Clinical Microbiology 1 MCQS

November 2019

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. The bacterial species that has cocci in clusters is

(A) Treponema spp.

(B) Streptococcus spp.

(D) Staphylococcus spp.*

2. Which of the following is the result when culture microorganism utilize citrate as their sole carbon source on Simmons-Citrate agar?

(A) The agar change color from blue to black.

(B) The agar change color from red to yellow.

(D) The agar change color from blue to "Prussian blue".*

3. Which of the following media is NOT differential?

(A) Blood agar

(B) Nutrient agar*

(D) Mannitol Salt agar

4. Which of the following organism will give positive reaction in the coagulase test?

(A) Staphylococcus aureus*

(B) Streptococcus agalactiae

(D) Staphylococcus saprophyticus

5. Which of the following antimicrobial sensitivity test can distinguished

Staphylococcus epidermidis from other coagulase-negative Staphylococci?

(A) niacin susceptible

(B) optochin susceptible

(D) novobiocin susceptible*

6. What would be the final colour of Gram stained for Staphylococcus saprophyticus if the decolorizing step is done properly?

(A) blue*

(B) pink

(D) yellow

7. Which of the following organism in a Lancefield Group B?

(A) Echerichia coli

(B) Campylobacter jejuni

(D) Streptococcus agalactiae*--beta hemolysis, bacitracin negative, CAMP test positive

8. An organism isolated from a vaginal swab is oxidase-positive and on Gram stain appeared as Gram-negative diplococci. The organism metabolizes only glucose.

What is the presumptive identification of this organism?

(A) Salmonella typhi

(B) Neisseria lactamica

(D) Corynebacterium diphteriae

Which of the following MOST likely the causative organism based on results in

Figure 1?

(A) Campylobacter coli

(B) Treponema pallidum

(D) Mycobacterium leprae

10. Loeffler’s serum slope is normally used to isolate

(A) Bacillus anthracis

(B) Helicobacter pylori

(D) Corynebacterium diphtheriae*

11. Which of the following is the color of Vibrio cholerae colonies on Thiosulfate Citrate Bile Salts (TCBS) agar?

(A) blue

(B) green

(D) yellow*--sucrose fermenter

12. Which of the following organism will give high isotope Urea C13 or C14 reading in the carbon dioxide (CO2) emitted in the breath for Urea Breath test?

(A) Vibro cholerae

(B) Helicobacter pylori*

(D) Streptococcus pyogenes

13. Which of the following organism requires only "V (nicotinamide adenine dinucleotide)" factor for growth?

(A) Haemophilus ducreyi--X factor (haemin)

(B) Haemophilus influenza--X & V

(D) Haemophilus parahaemolyticus

14. Which of the following senario can cause Haemophilus influenzae satellite around colonies of Staphylococcus aureus?

(A) Over crowded plate

(B) Act as normal flora, Staphylococcus

(D) Secretion of NAD (V factor) by Staphylococcus*

15. Which of the following characteristic is shared by all enterobacteriaceae?

(A) Gram positive

(B) ferment lactose

(D) facultative anaerobes*

16. Which of the following is TRUE about Proteus vulgaris?

(A) Gram-positive bacilli

(B) lactose fermenting organism

(D) non-glucose fermenting organism

17. Which of the following is characteristic of Shigella boydii?

(A) It is non-motile*

(B) It can produce gas

(D) It is a lactose fermenting organism

18. Which of the following is a result for Salmonella typhi in Double Sugar Iron agar?

(A) Does not produce gas*

(B) Lactose fermenting organism

(D) Cannot produce hydrogen sulfide

19. Which of the following is the characteristic genus Mycobacterium?

(A) It is motile.

(B) It is capsulated.

(D) It is an acid-fast bacteria.*

20. Which of the following enriched medium is used to isolate Mycobacterium tuberculosis?

(A) MacConkey agar

(B) Loeffler’s serum slope

(D) Xylose-Lysine-Deoxycholate agar

21. What sample can be used to diagnose pulmonary tuberculosis?

(A) hair

(B) urine

(D) sputum*

22. Which of the following is TRUE regarding Mycobacterium leprae?

(A) It is cocci in chain.

(B) It is Gram positive bacteria.

(D) It has been grown in artificial media.

23. Which of the following is the characteristic genus Actinomyces?

(A) It form endospores.

(B) It is a cocci in clusters.

(D) It is a Gram negative bacteria.

24. Which of the following microscope can be used to see Treponema pallidum?

(A) Confocal microscopy

(B) Dark-field microscopy*

(D) Phase-contrast microscopy

25. Which of the following is a NOT a characteristic of Leptospira interrogans?

(A) motile

(B) cocci bacteria*

(D) Gram negative

26. Which disease is detected by the Venereal Disease Research Laboratory (VDRL) test?

(A) Syphilis*--Treponema pallidum

(B) Chancroid

(D) Whooping cough

27. Which of the following is TRUE about Mycoplasma pneumoniae?

(A) It can be stained with Dienes stain.*

(B) It’s normal flora in the human lungs.--genital tract

(D) It cannot hemolyze guinea pig red blood cells.

28. Which of the following staining techniques is commonly used to identify Chlamydia trachomatis?

(A) Gram stain

(B) Diene’s stain

(D) Acid-fast stain

29.

When stained this organism is large, gram positive rods with square end, found in chains, non motile and has antiphagocytic capsule composed of D-glutamate. It causes anthrax.

Figure 2

What is the presumptive identification of the organism described in figure 2?

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30. Which genus has a characteristic of "Chinese letter" arrangement?

(A) Haemophilus

(B) Campylobacter

(D) Corynebacterium.*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. a. List FOUR (4) basic biochemical tests in bacteria identification. (2 Marks)

OF-glucose, Simmon-Citrate Agar, Urease test, Phenylaline Deaminase test

b. Briefly explain the purpose and the principle of the FOUR (4) basic biochemical tests stated in 1 (a). (8 Marks)

OF-glucose: identify oxidative and fermentative, pH low, bromthymol blue turns yellow, acid

Simmon-Citrate Agar: citrate utilization ass carbon source, bromthymol blue turns into Prussian blue, citrate utilization occurs

Urease test: identify Proteus from non-lactose fermenting enterics, urease produced by microbes attacks nitrogen and carbon bond in amine compounds, phenol red changes to deep pink, alkaline end product ammonia produced

Phenylaline Deaminase test: ability to deaminate phenylaline into phenylpyruvic acid, dark green color is a positive result, ferric acid react with phenylpyruvic acid after incubation

2. a. List FIVE (5) general characteristics of the Serratia marcescens (5 Marks)

Gram negative

Opportunistic pathogen with nosocomial outbreaks

Ferments lactose slowly

TSA: pink to red pigment (prodigiosin)

Cause hospital acquired infections of urinary/respiratory tract

b. Briefly describe the identification of Proteus vulgaris. (5 Marks)

Specimen collected: urine, pus

Blood: Swarming growth

MacConkey: lactose -

DSI: red slant lactose-, yellow butt ferment glucose, black H2S

Gram stain: negative

Urease: positive

Oxidase: negative

3. A 55 year old woman developed severe vomiting and diarrhoea approximately 12 hours after her return from a one day vacation in Bangkok. She went into shock and was brought to the emergency room by her family members. Outbreaks of cholera were reported in Bangkok and neighbouring regions during the woman's visit.

a. Name the organism suspected of causing this cholera outbreak. (2 Marks)

Vibrio cholera

b. How do you perform a laboratory diagnosis on this case? Name the type of specimen suitable for her diagnosis. (8 Marks)

TCBS: yellow, ferments sucrose

Transport medium: Venkathraman-Ramakrishnan, Cary-Blair, Alkaline peptone water

MacConkey: colorless then pink

Blood Agar: no hemolysis

Nutrient Agar: moist, round discs

catalase, oxidase positive

SECTION C: ESSAY QUESTIONS (40 MARKS)

ANSWER ALL QUESTIONS

1. Describe the characteristics of Streptococcus species and with a schematic diagram describe the identification procedure for Streptococcus species. (10 Marks)

Gram positive, pairs/chains

Alpha hemolysis: penumoniae bile solubility optochin, viridans

Beta hemolysis: pyogenes A bacitracin PYR, agalactiae B CAMP

Gamma hemolysis: enterococcus bile esculin

Catalase negative

2. Describe FIVE (5) general characteristics of Enterobacter aerogenes and its laboratory diagnosis procedures. (10 Marks)

Facultative anaerobic, ferments glucose, none have cytochrome oxidase, non spore forming, motile

MacConkey: red, lactose fermenting colonies

DSI: yellow slant, yellow butt, produces gas, no H2S

3. Describe important properties of Haemophilus influenza including morphological characteristics and laboratory investigation. (20 Marks)

Haemophilus, small pleomorphic gram- rod or coccobacilli, catalase & oxidase +, glucose +, growth factor, meningitis, pneumonia, optimum temperature 37

X hemin V nicotinamide adenine dinuceotide: influenza

Blood Agar: convex, smooth, pale, grey, transparent colonies

Demonstrate satellitism around Staphylococcus aureus which excrete V factor

Specimen collected: CSF, blood, throat swab, sputum, pus, never be refrigerated

August 2019

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. Which of the following characteristic of microorganism that change the medium color of glucose test from green to yellow?

(A) aerobic

(B) oxidative

(D) microaerophilic

2. What is the BEST temperature for incubate clinical specimen in the laboratory?

(A) 27° C

(B) 37° C*

(D) 57° C

3. What would be the final colour of Gram stain for Gram negative bacteria?

(A) blue

(B) pink*

(D) purple

4. Which of the following statement is TRUE about identification of Staphylococcus species?

(A) Staphylococcus epidermidis is resistant to 5ug novobiocin.--sensitive

(B) Coagulase test is the confirmation test for Staphylococcus aureus.*

(D) Oxidase test is used to differentiate Staphylococcus from Streptococcus.--catalase

5. Staphylococcus species can be differentiated from streptococcus species by

(A) Gram reactivity

(B) catalase reaction*

(D) acid fast staining

A bacteria culture from a newborn with pneumonia reveals the characteristics in

Figure 1. What is the MOST likely organism responsible?

(A) Streptococcus pyogenes--bacitrin sensitive

(B) Streptococcus agalactiae*

(D) Staphylococcus saprophyticus

7. Which of the following test can differentiate Streptococcus pneumonia and Streptococcus viridians?

(A) catalase test

(B) oxidase test

(D) bile solubility test*--optochin

8. Which of the following is TRUE about Neisseria gonorrhoeas?

(A) it is bacillus in shape.

(B) it metabolizes only glucose.*

(D) it can grow on New York City agar.*

9. Which of the following medium is NOT a transport media for Vibrio cholerae?

(A) Cary-Blair medium

(B) Loeffler’s serum slope*

(D) Venkatraman-Ramakrishnan medium

10.

Figure 2

Gram-positive rod-like forms", may appear end to end giving a bamboo appearance arrangement, the colonies on blood agar is non hemolytic on 5% blood agar, raised large and grayish white.

Which of the following organisms is related to Figure 2?

(A) Escherichia coli

(B) Bacillus anthracis*

(D) Staphylococcus aureus

11.

Figure 3

By referring the characteristics in Figure 3, choose from the following the MOST likely causative organism?

(A) Bacillus anthracis

(B) Shigella dysenteriae

(D) Mycobacterium tuberculosis

12. What is the special component in chocolate agar that provides supplement for the isolation of Haemophilus species?

(A) beta aminolevulinic acid and hematin.

(B) heme group and polyribose ribotol phosphate.

(D) alpha aminolevulinic acid and nicotinamide adenine dinucleotide.

13.

Figure 4

A Gram-negative bacilli, actively motile, positive oxidase test, growth on Skirrow’s medium but failure to grow at 25 °C.

Which of the following bacteria is related to Figure 4?

(A) Vibro cholerae

(B) Echerichia coli

(D) Propionibacterium granulosum

14. Which of the following is TRUE regarding Haemophilus ducreyi?

(A) it is a coccus

(B) it is a Gram-positive

(D) it does require factor V

15. Which of the characteristic of Vibrio cholerae is similar with Helicobacter pylori?

(A) non-motile

(B) Gram-positive

(D) oxidase negative

16. Which of the following is NOT TRUE about Proteus vulgaris?

(A) Gram-negative bacilli

(B) non lactose fermented

(D) swarming growth on blood agar

17. Which of the following is characteristic of Shigella boydii?

(A) motile

(B) lactose fermented

(D) produces hydrogen sulfide

18.

Figure 5

Caused gastric ulcer, positive urease, catalase and oxidase.

Which of the following bacteria is MOST likely related to Figure 5?

(A) Echerichia coli

(B) Vibrio cholera

(D) Campylobacter jejuni

19. All of the following enriched media are used to isolate Mycobacterium tuberculosis EXCEPT

(A) blood agar*

(B) Dorset Egg

(D) Lowenstein-Jensen medium

20. Leprotamous leprosy is caused by

(A) Mycobacterium leprae*

(B) Neisseria gonorrhoeae

(D) Mycobacterium tuberculosis

21. Mycobacterium tuberculosis is transmitted by

(A) sexual intercourse

(B) ingestion of eggs in the food

(D) ingestion of cysts in contaminated water

22. Which of the following staining is required for diagnosis Mycobacterium tuberculosis?

(A) Gram staining

(B) Albert staining

(D) acid fast staining*

23. The etiological agent for acne is

(A) Actinomyces species

(B) Staphylococcus species

(D) Propionibacterium species*

24. What disease can caused by Treponema pallidum?

(A) syphilis*

(B) meningitis

(D) tuberculosis

25. Which of the following characteristic describe the Leptospira interrogan?

(A) non motile

(B) spiral shape*

(D) Gram-positive bacteria

26. Venereal Disease Research Laboratory (VDRL) test is used to detect

(A) leprosy

(B) syphilis*

(D) tuberculosis

27. Which of the following is TRUE about Mycoplasma pneumoniae?

(A) It cannot hemolyze red blood cells.

(B) It can be stained with Gram staining.--Diene's

(D) It cannot be transmitted via aerosolized droplets.

28. Which of the following staining technique is commonly used to identify Chlamydia trachomatos?

(A) Gram staining

(B) Giemsa staining*--direct fluorescent antibody

(D) Acid-fast staining

29.

Figure 6

Large Gram-positive rods with square ends, found in chains, and its antiphagocytic capsule is composed of D-glutamate.

The presumptive characteristics of bacteria in Figure 6 is

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30.

Figure 7

Large Gram-positive rods bacilli, chinese letter pattern, grow on Tellurite blood agar and Airbone droplets transmission.

The presumptive identification of bacteria in Figure 7 is

(A) Echerichia coli

(B) Helicobacter pylori

(D) Corynebacterium diphtheriae*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. Describe the species of Haemophilus aegyptius based on the following topics:

a. Staining characteristics of Haemophilus aegyptius. (2 Marks)

gram - rod

b. Morphology of Haemophilus aegyptius. (3 Marks)

Pleomorphic gram - rods

Small, uniform coccobacillus in specimens

Long, filamentous rods in culture

c. Diseases cause by Haemophilus aegyptius. (5 Marks)

Conjunctivitis

Purpuric fever

Meningitis

Pneumonia

Cellulitis

Bacteremia

2. a. Identify the general characteristics of the Proteus vulgaris. (5 Marks)

NF of intestine

Opportunistic pathogen

Cause nosocomial UTI

Gram - rod

Ferments glucose

Non lactose fermenter

Oxidase negative

b. Briefly describe the laboratory diagnosis of Escherichia Coli. (5 Marks)

Facultative anaerobe

DSI: yellow slant, yellow butt, gas, no H2S

MacConkey: red, lactose+

Gram stain: negative rod

Oxidase -

Motile

3. a. Outline the general characteristics of Shigella dysenteriae. (4 Marks)

Cause dysentry

Gram - rod

Oxidase -

Lactose -

Glucose +

b. Briefly explain the laboratory identification of Shigella boydii. (6 Marks)

Specimen collected: stool

Gram stain: - rod

Oxidase -

Urease: -

TSI: red slant, yellow butt, n H2S

MacConkey: clear, colorless

CLED: blue

XLD: red to pink without black center

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER ALL QUESTIONS

1. Describe in details the identification with schematic diagram of Staphylococcus species. (10 Marks)

aureus: coagulase +, DNAse +, MSA ferments mannitol acid products pH low phenol red indicator turns yellow

epidermidis: novobiocin +

saprophyticus: novobiocin -

Catalase +

2. Explain about important properties of Mycobacterium tuberculosis for microbial identification and laboratory diagnosis. (10 Marks)

Acid-fast

Fungus like

Obligate aerobe

Non motile, non capsulated, non sporing

Slow growing

Resistant to acids, alkalis, dehydration

Cause TB

Lowenstein-Jensen medium 8 w

no growth on Blood Agar

BACTEC medium 2 w produce radioactive CO2

Specimen collected: sputum

Catalase-peroxidase positive

Niacin test: Canary yellow

3. Describe in details SEVEN (7) biochemical tests in microbiology laboratory. Provide purpose and the principle of each test. (20 Marks)

September 2018

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. The bacterial species that has cocci in clusters is

(A) Treponema spp.

(B) Streptococcus spp.

(D) Staphylococcus spp.*

2. Which of the following is the results bacteria culture utilize citrate as their sole carbon source on Simmons-Citrate agar?

(A) The agar change color from blue to black.

(B) The agar change color from red to yellow.

(D) The agar change color from blue to "Prussian blue".*

3. Which of the following media is NOT differential?

(A) Blood agar

(B) Nutrient agar*

(D) Mannitol Salt agar

4. Which of the following organisms will give positive reaction in the coagulase test?

(A) Staphylococcus aureus*

(B) Streptococcus agalactiae

(D) Staphylococcus saprophyticus

5. Which of the following antimicrobial sensitivity test can distinguished

Staphylococcus epidermidis from other coagulase-negative Staphylococci?

(A) niacin susceptible

(B) optochin susceptible

(D) novobiocin susceptible*

6. What would be the final colour of Gram stained for Staphylococcus saprophyticus if the decolorizing step is done properly?

(A) blue*

(B) pink

(D) yellow

7. Which of the following organism in a Lancefield Group B?

(A) Echerichia coli

(B) Campylobacter jejuni

(D) Streptococcus agalactiae*

An organism isolated from a vaginal swab is oxidase-positive, Gram stain appeared as Gram-negative diplococci and metabolizes only glucose.

Figure 1

What is the presumptive identification of the organism described in Figure 1?

(A) Salmonella typhi

(B) Neisseria lactamica

(D) Corynebacterium diphteriae

9. Loeffler’s serum slope is normally used to isolate

(A) Bacillus anthracis

(B) Helicobacter pylori*

(D) Corynebacterium diphtheriae

10. Which of the following is the color of Vibrio cholera colonies on Thiosulfate Citrate Bile Salts agar?

(A) blue

(B) green--V. parahaemolyticus and V. vulnificus

(D) yellow*

11.

Which of the following MOST likely causative organism on Figure 2?

(A) Campylobacter coli

(B) Treponema pallidum

(D) Mycobacterium leprae

12. Which of the following organisms will gives high isotope Urea C13 or C14 in the breath for Urea Breath test?

(A) Vibro cholera

(B) Helicobacter pylori*

(D) Streptococcus pyogenes

13. Which of the following organisms requires only "V (nicotinamide adenine dinucleotide)" factor for growth?

(A) Haemophilus ducreyi

(B) Haemophilus influenza

(D) Haemophilus parahaemolyticus

14. Which of the following can cause Haemophilus influenzae satellite around colonies of Staphylococcus aureus?

(A) secretion of heam

(B) act as normal flora

(D) secretion of NAD (V factor)*

15. Which of the following the characteristic share by all Enterobacteriaceae?

(A) Gram positive--negative

(B) ferment lactose--glucose

(D) facultative anaerobes*

16. Which of the following is TRUE about Proteus vulgaris?

(A) Gram-positive bacilli

(B) lactose fermenting organism

(D) non glucose fermenting organism

17. Which of the following is characteristic of Shigella boydii?

(A) It is non motile.*

(B) It can produce gas.

(D) It is a lactose fermenting organism.

18. Which of the following is a result for Salmonella typhi in Double Sugar Iron agar?

(A) Does not produce gas.*

(B) Lactose fermenting organism.

(D) Cannot produces hydrogen sulfide.

19. Which of the following is the characteristic genus Mycobacterium?

(A) It is a motile.

(B) It is a capsulated.

(D) It is an acid-fast bacteria.*

20. Which of the following medium are enriched media which is used to isolate Mycobacterium tuberculosis?

(A) MacConkey agar

(B) Loeffler’s serum slope

(D) Xylose-Lysine-Deoxycholate agar

21. What sample can be used to diagnose tuberculosis?

(A) hair

(B) urine

(D) sputum*

22. Which of the following is TRUE about Mycobacterium leprae?

(A) It is cocci in chain.

(B) It is Gram positive bacteria.

(D) It has been grown in artificial media.

23. Which of the following characteristic of genus Actinomyces?

(A) It is slow growing.*

(B) It is form endospores.

(D) It is a Gram negative bacteria.

24. Which of the following microscope used to observe Treponema pallidum?

(A) confocal microscopy

(B) dark-Field microscopy*

(D) phase-Contrast microscopy

25. Which of the following is a NOT characteristic of Leptospira interrogans?

(A) motile

(B) cocci bacteria*

(D) Gram negative

26. Which disease is detected by the VDRL (Venereal Disease Research Laboratory) test?

(A) syphilis*

(B) chancroid

(D) whooping cough

27. Which of the following is TRUE about Mycoplasma pneumoniae?

(A) It can be stained with Dienes stain.*

(B) It can be transmitted to by insect bites.--droplets

(D) It cannot hemolyze guinea pig red blood cells.--hominis

28. Chlamydia trachomatis is the causative organism for

(A) Chancroid

(B) Gonorrhea

(D) Lymphogranuloma venereum*

29.

When stained this organism is large, gram positive rods with square end, found in chains, non motile and has antiphagocytic capsule composed of D-glutamate.

It’s causes anthrax.

Figure 3

What is the presumptive identification of the organism described in Figure 3?

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30. Which genus has a characteristic of "Chinese letter" arrangement?

(A) Haemophilus

(B) Campylobacter

(D) Corynebacterium.*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. a. Identify FOUR (4) basic biochemical tests. (2 Marks)

b. Based on 1 (a), explain the purpose and principle of FOUR (4) basic biochemical test. (8 Marks)

2. a. Determine the general characteristics of the Serratia marcescens. (5 Marks)

b. Briefly describe the laboratory diagnosis of Proteus vulgaris. (5 Marks)

a. Name the organism suspected of causing this cholera outbreak. (2 Marks)

b. Explain the laboratory diagnosis procedure regarding the above case including type of specimen collected. (8 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

With the aid of schematic diagram discuss the identification of Streptococcus species included appearances on blood agar with alpha, beta and gamma haemolysis. Give ONE (1) example of an organism for each of the haemolysis. (20 Marks)

Question 2

Describe the general characteristics and laboratory diagnosis of Enterobacterm aerogenes. (20 Marks)

Question 3

Describe the general characteristics and laboratory identifications of Haemophilus influenzae. (20 Marks)

February 2018

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. Which of the following characteristic of microorganism that change the medium color of glucose test from green to yellow?

(A) aerobic

(B) oxidative

(D) microaerophilic

2. What is the BEST temperature for incubate clinical specimen in the laboratory?

(A) 27° C

(B) 37° C*

(D) 57° C

3. What would be the final colour of Gram stain for Gram negative bacteria?

(A) blue

(B) pink*

(D) purple

4. Which of the following statement is TRUE about identification of Staphylococcus species?

(A) Staphylococcus epidermidis is resistant to 5ug novobiocin.

(B) Coagulase test is the confirmation test for Staphylococcus aureus.*

(D) Bacitracin sensitivity test is the confirmation test for Staphylococcus saprophyticus.

5. Staphylococcus species can be differentiate from streptococcus species by

(A) Gram reactivity

(B) catalase reaction*

(D) acid fast staining

A bacteria culture from a newborn with pneumonia reveals the characteristics in Figure 1. What is the MOST likely organism responsible?

(A) Streptococcus pyogenes

(B) Streptococcus agalactiae*

(D) Staphylococcus saprophyticus

7. Which of the following test can differentiate Streptococcus pneumonia and Streptococcus viridians?

(A) catalase test

(B) oxidase test

(D) bile solubility test*

8. Which of the following is TRUE about Neisseria gonorrhoeas?

(A) It is bacillus in shape

(B) It metabolizes only glucose*

(D) It can grow on New York City agar*

9. Which of the following medium is NOT a transport media for Vibrio cholerae?

(A) Cary-Blair medium

(B) Loeffler’s serum slope*

(D) Venkatraman-Ramakrishnan medium

10.

Figure 2

Gram-positive rod-like forms", may appear end to end giving a bamboo appearance arrangement, the colonies on blood agar is non hemolytic on 5% blood agar, raised large and grayish white.

Which of the following organisms is related to Figure 2?

(A) Escherichia coli

(B) Bacillus anthracis*

(D) Staphylococcus aureus

11.

Figure 3

By referring the characteristics in Figure 3, choose from the following the MOST likely causative organism?

(A) Bacillus anthracis

(B) Shigella dysenteriae

(D) Mycobacterium tuberculosis

12. What is the special component in chocolate agar that provides supplement for the isolation of Haemophilus species?

(A) Beta aminolevulinic acid and hematin

(B) Heme group and polyribose ribotol phosphate

(D) Alpha aminolevulinic acid and nicotinamide adenine dinucleotide

13.

Figure 4

A Gram-negative bacilli, actively motile, positive oxidase test, growth on Skirrow’s medium but failure to grow at 25 °C.

Which of the following bacteria is related to Figure 4?

(A) Vibro cholerae

(B) Echerichia coli

(D) Propionibacterium granulosum

14. Which of the following is TRUE regarding Haemophilus ducreyi?

(A) It is a coccus

(B) It is a Gram-positive

(D) It does require factor V

15. Which of the characteristic of Vibrio cholerae is similar with Helicobacter pylori?

(A) non-motile

(B) Gram-positive

(D) oxidase negative

16. Which of the following is NOT TRUE about Proteus vulgaris?

(A) Gram-negative bacilli

(B) non lactose fermented

(D) swarming growth on blood agar

17. Which of the following is characteristic of Shigella boydii?

(A) motile

(B) lactose fermented

(D) produces hydrogen sulfide

18.

Figure 5

Caused gastric ulcer, positive urease, catalase and oxidase.

Which of the following bacteria is MOST likely related to Figure 5?

(A) Echerichia coli

(B) Vibrio cholerae

(D) Campylobacter jejuni

19. All of the following enriched media are used to isolate Mycobacterium tuberculosis EXCEPT

(A) blood agar*

(B) Dorset Egg

(D) Lowenstein-Jensen medium

20. Leprotamous leprosy is caused by

(A) Mycobacterium leprae*

(B) Neisseria gonorrhoeae

(D) Mycobacterium tuberculosis

21. Mycobacterium tuberculosis is transmitted by

(A) sexual intercourse

(B) ingestion of eggs in the food

(D) ingestion of cysts in contaminated water

22. Which of the following staining is required for diagnosis Mycobacterium tuberculosis?

(A) Gram staining

(B) Albert staining

(D) acid fast staining*

23. The etiological agent for acne is

(A) Actinomyces species

(B) Staphylococcus species

(D) Propionibacterium species*

24. What disease can caused by Treponema pallidum?

(A) syphilis*

(B) meningitis

(D) tuberculosis

25. Which of the following characteristic describe the Leptospira interrogan?

(A) non motile

(B) spiral shape*

(D) Gram-positive bacteria

26. Venereal Disease Research Laboratory (VDRL) test is used to detect

(A) leprosy

(B) syphilis*

(D) tuberculosis

27. Which of the following is TRUE about Mycoplasma pneumoniae?

(A) It cannot hemolyze red blood cells

(B) It can be stained with Gram staining

(D) It cannot be transmitted via aerosolized droplets

28. Which of the following staining technique is commonly used to identify Chlamydia trachomatos?

(A) Gram staining

(B) Giemsa staining*

(D) Acid-fast staining

29.

Figure 6

Large Gram-positive rods with square ends, found in chains, and its antiphagocytic capsule is composed of D-glutamate.

The presumptive characteristics of bacteria in Figure 6 is

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30.

Figure 7

Large Gram-positive rods bacilli, chinese letter pattern, grow on Tellurite blood agar and Airbone droplets transmission.

The presumptive identification of bacteria in Figure 7 is

(A) Echerichia coli

(B) Helicobacter pylori

(D) Corynebacterium diphtheriae*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. Describe the species of Haemophilus aegyptius based on the following topics:

a. Staining characteristics of Haemophilus aegyptius. (2 Marks)

b. Morphology of Haemophilus aegyptius. (3 Marks)

c. Diseases cause by Haemophilus aegyptius. (5 Marks)

2. a. Identify the general characteristics of the Proteus vulgaris. (5 Marks)

b. Briefly describe the laboratory diagnosis of Escherichia Coli. (5 Marks)

3. a. Outline the general characteristics of Shigella dysenteriae. (4 Marks)

b. Briefly explain the laboratory identification of Shigella boydii. (6 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

Describe in detail SEVEN (7) biochemical tests in microbiology laboratory. Provide purpose and the principle of each test. (20 Marks)

Question 2

Describe in detail the characteristics and identification of Streptococcus species. Provide the schematic diagram for the identification of Streptococcus species. (20 Marks)

Question 3

Discuss the important properties of Mycobacterium tuberculosis for microbial identification and laboratory diagnosis. (20 Marks)

September 2017

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. Streptococcus are Gram positive cocci that tend to grow in

(A) pairs

(B) single

(D) clusters

2. A known culture of Micrococcus appears pink in Gram stain and coccus in shape.

This result could be

(A) incorrect as the bacteria are not cocci

(B) correct as the bacteria is Gram negative

(D) correct because the bacteria show variability in colour and shape

3. What would be the final colour of Gram stained bacteria if the decolorizing step is not done properly?

(A) Pink

(B) White

(D) Yellow

4. Identify the statement which is NOT TRUE.

(A) Staphylococcus saprophyticus is resistant to 5ug novobiocin.

(B) Streptococcus pneumoniae produces beta hemolysis on blood agar.*--alpha

(D) Optochin sensitivity test is the confirmation test for Streptococcus pneumoniae.

5. Which of the following organisms will give positive reaction in the coagulase test?

(A) Staphylococcus aureus*

(B) Streptococcus pyogenes

(D) Staphylococcus epidermidis

6. The Lancefield grouping of streptococci is based on the

(A) proteins found in cell walls*

(B) precipitation of cell wall carbohydrate

(D) fermentation/oxidation of specific carbohydrate

7. The Christie, Atkins, and Munch-Peterson (CAMP) test is used as a presumptive test to identify

(A) enterococcus

(B) group D streptococci

(D) Streptococcus agalactiae*

Organism "X" isolated from a vaginal swab appeared as gram negative diplococci. The organism metabolizes only glucose and oxidase are positive.

Figure 1

What is the presumptive identification of organism "X" in Figure 1?

(A) Neisseria lactamica

(B) Neisseria gomorrhoea*

(D) Pseudomonas aeruginosa

9. Culture on Modified Thayer Martin (MTM) medium of a vaginal swab produced several colonies of diplococci that were oxidase positive. Given the following carbohydrate reactions, select the MOST likely causative organism.

(A) Bacillus anthracis

(B) Neisseria meningitidis*

(D) Mycobacterium tuberculosis

10.

The genus for the group of organisms which is defined as "gram-positive rod-like forms", has a characteristic "Chinese letter" arrangement; often with club-shaped swellings at the poles with irregularly staining segments or granules.

Figure 2

Which of the following organism is likely describe in Figure 2?

(A) Bacillus

(B) Haemophilus

(D) Corynebacterium*

11. Which of the following medium is MOST suitable to culture Vibrio spp?

(A) DCA Agar

(B) TCBS agar*

(D) Lowestein Jensen Medium

12.

A bacteria may produces a very powerful urease, catalase and oxidase positive. They also can cause gastric ulser.

Figure 3

Which of the following organism is MOST likely described in Figure 3?

(A) Vibro cholerae

(B) Echerichia coli

(D) Campylobacter jejuni

13. The colonies that exhibit satellite formation near colonies of staphylococci belong to

(A) Neissena meningitidis

(B) Neissena gonorrhoeae

(D) Streptococcus agalactiae

14. Which of the following organisms requires both "X" and "V" factors for growth?

(A) Haemophilus ducreyi--X factor

(B) Haemophilus aegyptius*--H. influenzae

(D) Haemophilus parahaemolyticus

15. Which of the following characteristic share for all Enterobacteriaceae?

(A) Gram-positive

(B) ferment glucose*

(D) reduce nitrates to nitrites

16. Which of the following is TRUE about Proteus mirabilis?

(A) lactose fermented

(B) Gram-positive bacilli

(D) Can produce swarming growth on blood agar medium*

17. The Shigella boydii

(A) is motile

(B) is lactose fermented

(D) can produce hydrogen sulfida

18. Which of the following may positive in oxidase test?

(A) Salmonella typhi

(B) Proteus mirabilis

(D) Pseudomonas aeruginosa*--vibrio

19. Which of the following stain is required to prepare a direct smear of sputum suspected of Mycobacterium tuberculosis?

(A) Indian ink

(B) Gram stain

(D) Carbol fuchsin

20. What microbe can cause Tuberculoid Leprosy?

(A) Mycobacterium leprae*

(B) Neisseria gonorrhoeae

(D) Mycobacterium tuberculosis

21. Lowenstein-Jensen medium are enriched media which is used to isolate

(A) Neisseria gonorrhoeae.

(B) Haemophilus influenzae.

(D) Corynebacterium diphtheriae.

22. Which of the following stain is required to prepare smear of skin suspected of Mycobacterium leprae?

(A) Indian ink

(B) Gram stain

(D) Acid fast stain*

23.

Physician ordered a set of three blood cultures drawn on his patient. After 48 hours of incubation, one of the bottles was positive for Propionibacterium acnes while the other two remained negative.

Figure 4

What is the MOST likely explanation for this observation in Figure 4?

(A) The patient has sepsis.

(B) The two negative bottles belonged to another patient.

(D) Propionibacterium acnes are skin contaminants due to improper venipuncture technique.*

24. Treponema pallidum can cause

(A) syphilis*

(B) meningitis

(D) tuberculosis

25. Which of the following is a characteristic for Leptospira interrogans?

(A) non motile

(B) Gram-positive

(D) seen under dark ground microscope*

26. Which of the following disease is detected by the Venereal Disease Research Laboratory test?

(A) leprosy

(B) syphilis*

(D) tuberculosis

27. Which of the following is NOT TRUE about Mycoplasma pneumoniae?

(A) resemble fried eggs

(B) can be stained with Dienes stain

(D) can be transmitted to close contact via aerosolized droplets

28. Which of the following staining techniques is commonly used to identify Chlamydia trachomatos?

(A) Gram stain

(B) Diene’s stain

(D) Acid-fast stain

29.

Gram-positive rods with square ends, found in chains, non-motil, its antiphagocytic capsule is composed of D-glutamate and cause anthrax.

Figure 5

Which of the following bacteria is MOST likely described in Figure 5?

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30. Tellurite medium is normally used to isolate

(A) Neisseria gonorrhoeae

(B) Staphylococcus aureus

(D) Corynebacterium diphtheriae*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. a. Draw and name shape of bacteria. (4 Marks)

b. Explain the general steps in diagnostic isolation and identification of bacteria. (6 Marks)

2. A 55 year old woman developed severe vomiting and diarrhoea approximately 12 hours after her return from a one day vacation in Bangkok. She went into shock and was brought to the emergency room by her family members. Outbreaks of cholera were reported in Bangkok and neighbouring regions during the woman's visit.

a. Name the organism suspected of causing the cholera outbreak. (2 Marks)

b. Explain the laboratory diagnosis on the cholera outbreak and state the type of specimen received. (8 Marks)

3. a. Describe the general characteristics of Mycobacterium tuberculosis. (5 Marks)

b. Describe about laboratory diagnosis of Mycobacterium tuberculosis. (5 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

With the aid of diagram, discuss the identification methods of Staphylococcus and Streptococcus species. (20 Marks)

Question 2

Explain the properties and laboratory diagnosis of Haemophilus influenzae. (20 Marks)

Question 3

Discuss general features and laboratory diagnosis of Escherichia coli. (20 Marks)

January 2017

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. Which of the following characteristic of microorganism that change the medium color of glucose test from green to yellow?

(A) aerobic

(B) oxidative

(D) microaerophilic

2. What is the BEST temperature for incubate clinical specimen in the laboratory?

(A) 27° C

(B) 37° C*

(D) 57° C

3. What would be the final colour of Gram stain for Gram negative bacteria?

(A) blue

(B) pink*

(D) purple

4. Which of the following statement is TRUE about identification of Staphylococcus species?

(A) Staphylococcus epidermidis is resistant to 5ug novobiocin.

(B) Coagulase test is the confirmation test for Staphylococcus aureus.*

(D) Oxidase test is used to differentiate Staphylococcus from Streptococcus.

5. Staphylococcus species can be differentiate from streptococcus species by

(A) Gram reactivity

(B) catalase reaction*

(D) acid fast staining

Figure 1

A bacteria culture from a newborn with pneumonia reveals the characteristics in Figure 1. What is the MOST likely organism responsible?

(A) Streptococcus pyogenes

(B) Streptococcus agalactiae*

(D) Staphylococcus saprophyticus

7. Which of the following test can differentiate Streptococcus pneumonia and Streptococcus viridians?

(A) catalase test

(B) oxidase test

(D) bile solubility test*

8. Which of the following is TRUE about Neisseria gonorrhoeas?

(A) It is bacillus in shape.

(B) It metabolizes only glucose.*

(D) It can grow on New York City agar.*

9. Which of the following medium is NOT a transport media for Vibrio cholerae?

(A) Cary-Blair medium

(B) Loeffler’s serum slope*

(D) Venkatraman-Ramakrishnan medium

10.

Figure 2

Gram-positive rod-like forms", may appear end to end giving a bamboo appearance arrangement, the colonies on blood agar is non hemolytic on 5% blood agar, raised large and grayish white.

Which of the following organisms is related to Figure 2?

(A) Escherichia coli

(B) Bacillus anthracis*

(D) Staphylococcus aureus

11.

Figure 3

By referring the characteristics in Figure 3, choose from the following the MOST likely causative organism?

(A) Bacillus anthracis

(B) Shigella dysenteriae

(D) Mycobacterium tuberculosis

12. What is the special component in chocolate agar that provides supplement for the isolation of Haemophilus species?

(A) Beta aminolevulinic acid and hematin.

(B) Heme group and polyribose ribotol phosphate.

(D) Alpha aminolevulinic acid and nicotinamide adenine dinucleotide.

13.

Figure 4

A Gram-negative bacilli, actively motile, positive oxidase test, growth on Skirrow’s medium but failure to grow at 25 °C.

Which of the following bacteria is related to Figure 4?

(A) Vibro cholerae

(B) Echerichia coli

(D) Propionibacterium granulosum

14. Which of the following is TRUE regarding Haemophilus ducreyi?

(A) It is a coccus

(B) It is a Gram-positive

(D) It does require factor V

15. Which of the characteristic of Vibrio cholerae is similar with Helicobacter pylori?

(A) non-motile

(B) Gram-positive

(D) oxidase negative

16. Which of the following is NOT TRUE about Proteus vulgaris?

(A) Gram-negative bacilli

(B) non lactose fermented

(D) swarming growth on blood agar

17. Which of the following is characteristic of Shigella boydii?

(A) motile

(B) lactose fermented

(D) produces hydrogen sulfide

18.

Figure 5

Caused gastric ulcer, positive urease, catalase and oxidase.

Which of the following bacteria is MOST likely related to Figure 5?

(A) Echerichia coli

(B) Vibrio cholerae

(D) Campylobacter jejuni

19. All of the following enriched media are used to isolate Mycobacterium tuberculosis EXCEPT

(A) blood agar*

(B) Dorset Egg

(D) Lowenstein-Jensen medium

20. Leprotamous leprosy is caused by

(A) Mycobacterium leprae*

(B) Neisseria gonorrhoeae

(D) Mycobacterium tuberculosis

21. Mycobacterium tuberculosis is transmitted by

(A) sexual intercourse

(B) ingestion of eggs in the food

(D) ingestion of cysts in contaminated water

22. Which of the following staining is required for diagnosis Mycobacterium tuberculosis?

(A) Gram staining

(B) Albert staining

(D) acid fast staining*

23. The aetiological agent for acne is

(A) Actinomyces species

(B) Staphylococcus species

(D) Propionibacterium species*

24. What disease can caused by Treponema pallidum?

(A) syphilis*

(B) meningitis

(D) tuberculosis

25. Which of the following characteristic describe the Leptospira interrogan?

(A) non motile

(B) spiral shape*

(D) Gram-positive bacteria

26. Venereal Disease Research Laboratory (VDRL) test is used to detect y

(A) leprosy

(B) syphilis*

(D) tuberculosis

27. Which of the following is TRUE about Mycoplasma pneumoniae?

(A) It cannot hemolyze red blood cells.

(B) It can be stained with Gram staining.

(D) It cannot be transmitted via aerosolized droplets.

28. Which of the following staining technique is commonly used to identify Chlamydia trachomatos?

(A) Gram staining

(B) Giemsa staining*

(D) Acid-fast staining

29.

Figure 6

Large Gram-positive rods with square ends, found in chains, and its antiphagocytic capsule is composed of D-glutamate.

The presumptive characteristics of bacteria in Figure 6 is

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30.

Figure 7

Large Gram-positive rods bacilli, chinese letter pattern, grow on Tellurite blood agar and Airbone droplets transmission.

The presumptive identification of bacteria in Figure 7 is

(A) Echerichia coli

(B) Helicobacter pylori

(D) Corynebacterium diphtheriae*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. Describe the species of Haemophilus aegyptius based on the following topics:

a. Staining characteristics of Haemophilus aegyptius. (2 Marks)

b. Morphology of Haemophilus aegyptius. (3 Marks)

c. Diseases cause by Haemophilus aegyptius. (5 Marks)

2. a. Identify the general characteristics of the Proteus vulgaris. (5 Marks)

b. Briefly describe the laboratory diagnosis of Escherichia Coli. (5 Marks)

3. a. Outline the general characteristics of Shigella dysenteriae. (4 Marks)

b. Briefly explain the laboratory identification of Shigella boydii. (6 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

Describe in detail SEVEN (7) biochemical tests in microbiology laboratory. Provide purpose and the principle of each test. (20 Marks)

Question 2

Describe in detail the characteristics and identification with schematic diagram of Staphylococcus species. (20 Marks)

Question 3

Discuss the important properties of Mycobacterium tuberculosis for microbial identification and laboratory diagnosis. (20 Marks)

August 2016

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. The bacterial species that has cocci in clusters is

(A) Treponema spp.

(B) Streptococcus spp.

(D) Staphylococcus spp.*

2. Which of the following is the results when culture microorganism that can utilize citrate as their sole carbon source on Simmons-Citrate agar?

(A) The agar change color from blue to black.

(B) The agar change color from red to yellow.

(D) The agar change color from blue to "Prussian blue".*

3. Which of the following media is NOT differential?

(A) Blood agar

(B) Nutrient agar*

(D) Mannitol Salt agar

4. Which of the following organisms will give positive reaction in the coagulase test?

(A) Staphylococcus aureus*

(B) Streptococcus agalactiae

(D) Staphylococcus saprophyticus

5. Which of the following antimicrobial sensitivity test can distinguished Staphylococcus epidermidis from other coagulase-negative Staphylococci?

(A) niacin susceptible

(B) optochin susceptible

(D) novobiocin susceptible*

6. What would be the final colour of Gram stained for Staphylococcus saprophyticus if the decolorizing step is done properly?

(A) blue*

(B) pink

(D) yellow

7. Which of the following organism in a Lancefield Group B?

(A) Echerichia coli

(B) Campylobacter jejuni

(D) Streptococcus agalactiae*

8. An organism isolated from a vaginal swab is oxidase-positive and on Gram stain appeared as Gram-negative diplococci. The organism metabolizes only glucose.

What is the presumptive identification of this organism?

(A) Salmonella typhi

(B) Neisseria lactamica

(D) Corynebacterium diphteriae

Which of the following MOST likely causative organism on figure 3?

(A) Campylobacter coli

(B) Treponema pallidum

(D) Mycobacterium leprae

10. Loeffler’s serum slope is normally used to isolate

(A) Bacillus anthracis

(B) Helicobacter pylori

(D) Corynebacterium diphtheriae*

11. Which of the following is the color of Vibrio cholera colonies on Thiosulfate Citrate Bile Salts agar?

(A) blue

(B) green

(D) yellow*

12. Which of the following organisms will gives high isotope Urea C13 or C14 reading in the carbon dioxide (CO2) emitted in the breath for Urea Breath test?

(A) Vibro cholera

(B) Helicobacter pylori*

(D) Streptococcus pyogenes

13. Which of the following organisms requires only "V (nicotinamide adenine dinucleotide)" factor for growth?

(A) Haemophilus ducreyi

(B) Haemophilus influenza

(D) Haemophilus parahaemolyticus

14. Which of the following can cause Haemophilus influenzae satellite around colonies of Staphylococcus aureus?

(A) over crowded plate

(B) act as normal flora, Staphylococcus

(D) secretion of NAD (V factor) by Staphylococcus*

15. Which of the following the characteristic share by all Enterobacteriaceae?

(A) Gram positive

(B) ferment lactose

(D) facultative anaerobes*

16. Which of the following is TRUE about Proteus vulgaris?

(A) Gram-positive bacilli

(B) lactose fermenting organism

(D) non glucose fermenting organism

17. Which of the following is characteristic of Shigella boydii?

(A) It is non motile.*

(B) It can produce gas.

(D) It is a lactose fermenting organism.

18. Which of the following is a result for Salmonella typhi in Double Sugar Iron agar?

(A) Does not produce gas.*

(B) Lactose fermenting organism.

(D) Cannot produces hydrogen sulfide.

19. Which of the following is the characteristic genus Mycobacterium?

(A) It is a motile.

(B) It is a capsulated.

(D) It is an acid-fast bacteria.*

20. Which of the following medium are enriched media which is used to isolate Mycobacterium tuberculosis?

(A) MacConkey agar

(B) Loeffler’s serum slope

(D) Xylose-Lysine-Deoxycholate agar

21. What sample can be used to diagnose tuberculosis?

(A) hair

(B) urine

(D) sputum*

22. Which of the following is TRUE about Mycobacterium leprae?

(A) It is cocci in chain.

(B) It is Gram positive bacteria.

(D) It has been grown in artificial media.

23. Which of the following is the characteristic genus Actinomyces?

(A) It is slow growing.*

(B) It is form endospores.

(D) It is a Gram negative bacteria.

24. Which of the following microscope can be used to see Treponema pallidum?

(A) confocal microscopy

(B) dark-Field microscopy*

(D) phase-Contrast microscopy

25. Which of the following is a NOT characteristic of Leptospira interrogans?

(A) motile

(B) cocci bacteria*

(D) Gram negative

26. Which disease is detected by the VDRL (Venereal Disease Research Laboratory) test?

(A) syphilis*

(B) chancroid

(D) whooping cough

27. Which of the following is TRUE about Mycoplasma pneumoniae?

(A) It can be stained with Dienes stain.*

(B) It can be transmitted to by insect bites.

(D) It cannot hemolyze guinea pig red blood cells.

28. Chlamydia trachomatis is the causative organism for

(A) Chancroid

(B) Gonorrhea

(D) Lymphogranuloma venereum*

29.

When stained this organism is large, gram positive rods with square end, found in chains, non motile and has antiphagocytic capsule composed of D-glutamate.

It’s causes anthrax.

Figure 2

What is the presumptive identification of the organism described in figure 2?

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30. Which genus has a characteristic of "Chinese letter" arrangement?

(A) Haemophilus

(B) Campylobacter

(D) Corynebacterium.*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. a. Identify FOUR (4) basic biochemical tests. (2 Marks)

b. Provide the purpose and the principle of FOUR (4) basic biochemical tests. (8 Marks)

2. a. Determine the general characteristics of the Serratia marcescens. (5 Marks)

b. Briefly describe the laboratory diagnosis of Proteus vulgaris. (5 Marks)

a. Name the organism suspected of causing this cholera outbreak. (2 Marks)

b. Explain the laboratory diagnosis procedure regarding the above case including type of specimen collected. (8 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

Question 2

Describe the general characteristics and laboratory diagnosis of Enterobacter aerogenes. (20 Marks)

Question 3

Describe the general characteristics and laboratory identifications of Haemophilus influenzae. (20 Marks)

January 2016

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. Which of the following characteristic of microorganism that change the medium color of glucose test from green to yellow?

(A) aerobic

(B) oxidative

(D) microaerophilic

2. What is the BEST temperature for incubate clinical specimen in the laboratory?

(A) 27° C

(B) 37° C*

(D) 57° C

3. What would be the final colour of Gram stain for Gram negative bacteria?

(A) blue

(B) pink*

(D) purple

4. Which of the following statement is TRUE about identification of Staphylococcus species?

(A) Staphylococcus epidermidis is resistant to 5ug novobiocin.

(B) Coagulase test is the confirmation test for Staphylococcus aureus.*

(D) Oxidase test is used to differentiate Staphylococcus from Streptococcus.

5. Staphylococcus species can be differentiate from streptococcus species by

(A) Gram reactivity

(B) catalase reaction*

(D) acid fast staining

A bacteria culture from a newborn with pneumonia reveals the characteristics in

Figure 1. What is the MOST likely organism responsible?

(A) Streptococcus pyogenes

(B) Streptococcus agalactiae*

(D) Staphylococcus saprophyticus

7. Which of the following test can differentiate Streptococcus pneumonia and Streptococcus viridians?

(A) catalase test

(B) oxidase test

(D) bile solubility test*

8. Which of the following is TRUE about Neisseria gonorrhoeas?

(A) It is bacillus in shape.

(B) It metabolizes only glucose.*

(D) It can grow on New York City agar.*

9. Which of the following medium is NOT a transport media for Vibrio cholerae?

(A) Cary-Blair medium

(B) Loeffler’s serum slope*

(D) Venkatraman-Ramakrishnan medium

10.

Figure 2

Gram-positive rod-like forms", may appear end to end giving a bamboo appearance arrangement, the colonies on blood agar is non hemolytic on 5% blood agar, raised large and grayish white.

Which of the following organisms is related to Figure 2?

(A) Escherichia coli

(B) Bacillus anthracis*

(D) Staphylococcus aureus

11.

Figure 3

By referring the characteristics in Figure 3, choose from the following the MOST likely causative organism?

(A) Bacillus anthracis

(B) Shigella dysenteriae

(D) Mycobacterium tuberculosis

12. What is the special component in chocolate agar that provides supplement for the isolation of Haemophilus species?

(A) Beta aminolevulinic acid and hematin.

(B) Heme group and polyribose ribotol phosphate.

(D) Alpha aminolevulinic acid and nicotinamide adenine dinucleotide.

13.

Figure 4

A Gram-negative bacilli, actively motile, positive oxidase test, growth on Skirrow’s medium but failure to grow at 25 °C.

Which of the following bacteria is related to Figure 4?

(A) Vibro cholerae

(B) Echerichia coli

(D) Propionibacterium granulosum

14. Which of the following is TRUE regarding Haemophilus ducreyi?

(A) It is a coccus.

(B) It is a Gram-positive.

(D) It does require factor V.

15. Which of the characteristic of Vibrio cholerae is similar with Helicobacter pylori?

(A) non-motile

(B) Gram-positive

(D) oxidase negative

16. Which of the following is NOT TRUE about Proteus vulgaris?

(A) Gram-negative bacilli

(B) non lactose fermented

(D) swarming growth on blood agar*

17. Which of the following is characteristic of Shigella boydii?

(A) motile

(B) lactose fermented

(D) produces hydrogen sulfide

18.

Figure 5

Caused gastric ulcer, positive urease, catalase and oxidase.

Which of the following bacteria is MOST likely related to Figure 5?

(A) Echerichia coli

(B) Vibrio cholerae

(D) Campylobacter jejuni

19. All of the following enriched media are used to isolate Mycobacterium tuberculosis EXCEPT

(A) blood agar*

(B) Dorset Egg

(D) Lowenstein-Jensen medium

20. Leprotamous leprosy is caused by

(A) Mycobacterium leprae*

(B) Neisseria gonorrhoeae

(D) Mycobacterium tuberculosis

21. Mycobacterium tuberculosis is transmitted by

(A) sexual intercourse

(B) ingestion of eggs in the food

(D) ingestion of cysts in contaminated water

22. Which of the following staining is required for diagnosis Mycobacterium tuberculosis?

(A) Gram staining

(B) Albert staining

(D) acid fast staining*

23. The aetiological agent for acne is

(A) Actinomyces species

(B) Staphylococcus species

(D) Propionibacterium species*

24. What disease can caused by Treponema pallidum?

(A) syphilis*

(B) meningitis

(D) tuberculosis

25. Which of the following characteristic describe the Leptospira interrogan?

(A) non motile

(B) spiral shape*

(D) Gram-positive bacteria

26. Venereal Disease Research Laboratory (VDRL) test is used to detect

(A) leprosy

(B) syphilis*

(D) tuberculosis

27. Which of the following is TRUE about Mycoplasma pneumoniae?

(A) It cannot hemolyze red blood cells.

(B) It can be stained with Gram staining.

(D) It cannot be transmitted via aerosolized droplets.

28. Which of the following staining technique is commonly used to identify Chlamydia trachomatos?

(A) Gram staining

(B) Giemsa staining*

(D) Acid-fast staining

29.

Figure 6

Large Gram-positive rods with square ends, found in chains, and its antiphagocytic capsule is composed of D-glutamate.

The presumptive characteristics of bacteria in Figure 6 is

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30.

Figure 7

Large Gram-positive rods bacilli, chinese letter pattern, grow on Tellurite blood agar and Airbone droplets transmission.

The presumptive identification of bacteria in Figure 7 is

(A) Echerichia coli

(B) Helicobacter pylori

(D) Corynebacterium diphtheriae*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. Describe the species of Haemophilus aegyptius based on the following topics:

a. Staining characteristics of Haemophilus aegyptius. (2 Marks)

b. Morphology of Haemophilus aegyptius. (3 Marks)

c. Diseases cause by Haemophilus aegyptius. (5 Marks)

2. a. Identify the general characteristics of the Proteus vulgaris. (5 Marks)

b. Briefly describe the laboratory diagnosis of Escherichia Coli. (5 Marks)

3. a. Outline the general characteristics of Shigella dysenteriae. (4 Marks)

b. Briefly explain the laboratory identification of Shigella boydii. (6 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

Describe in detail SEVEN (7) biochemical tests in microbiology laboratory. Provide purpose and the principle of each test. (20 Marks)

Question 2

Describe in detail the characteristics and identification of Streptococcus species. Provide the schematic diagram for the identification of Streptococcus species. (20 Marks)

Question 3

Discuss the important properties of Mycobacterium tuberculosis for microbial identification and laboratory diagnosis. (20 Marks)

August 2015

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. Which of the following microorganism has a coccus in chain?

(A) Streptococcus spp.*

(B) Pneumococcus spp.

(D) Corynebacterium spp.

2. A known culture of Micrococcus appears pink in Gram stain and coccus in shape.

This result could be

(A) incorrect as the bacteria are not cocci

(B) correct as the bacteria is Gram negative

(D) correct because the bacteria show variability in colour and shape

3. What would be the final colour of Gram stained bacteria if the decolorizing step is not done properly?

(A) red

(B) pink

(D) purple*

4. Identify the statement which is NOT TRUE.

(A) Staphylococcus saprophyticus is resistant to 5ug novobiocin.

(B) Optochin sensitivity test is the confirmation test for Streptococcus pneumoniae.

(D) Catalase test is used to differentiate Staphylococcus from Streptococcus.

5. The Lancefield grouping of streptococci is based on the

(A) proteins found in cell walls*

(B) precipitation of cell wall carbohydrate

(D) fermentation/oxidation of specific carbohydrate

6. The Christie, Atkins, and Munch-Peterson (CAMP) test is used as a presumptive test to identify

(A) enterococcus

(B) group D streptococci

(D) Streptococcus agalactiae*

7. Which of the following test can be differentiated Staphylococcus aureus from Staphylococcus epidermidis?

(A) Motility

(B) Catalase

(D) Coagulase*

8. An organism isolated from a vaginal swab is oxidase-positive and on Gram stain appeared as Gram-negative diplococci. The organism metabolizes only glucose.What is the presumptive identification of this organism?

(A) Salmonella enteric

(B) Neisseria gonorrhoeas*

(D) Corynebacterium diphteriae

Culture on Modified Thayer Martin (MTM) medium of a vaginal swab produced several colonies of Gram-negative diplococci that were oxidase positive. Given the following carbohydrate reactions.

Glucose = Positive

Lactose = Negative

Sucrose = Negative

Maltose = Positive

Figure 1

Which of the following is the most likely causative organism describe in Figure 1?

(A) Salmonella enteric.

(B) Moraxella catarrhalis.

(D) Corynebacterium diphteriae.

10.

Figure 2

Which of the following organism is likely describe in Figure 2?

(A) Bacillus

(B) Haemophilus

(D) Corynebacterium*

11. Which of the following medium is MOST suitable to culture Vibrio spp?

(A) DCA Agar

(B) TCBS agar*

(D) Lowestein Jensen Medium

12. A bacteria may produces a very powerful urease, catalase and oxidase positive. They also can cause gastric ulser. Which of the following organism is most likely describe as above?

(A) Vibro cholerae

(B) Echerichia coli

(D) Campylobacter jejuni

13. Which of the following organisms requires both "X" and "V" factors for growth?

(A) Haemophilus ducreyi--X

(B) Haemophilus aegyptius*

(D) Haemophilus parahaemolyticus

14. All of the following statements are true on Haemophilus influenzae EXCEPT it

(A) requires growth factor

(B) does not require factor X*

(D) can cause meningitis among children

15. Which of the following may positive in oxidase test?

(A) Salmonella typhi

(B) Proteus mirabilis

(D) Pseudomonas aeruginosa*

16.

An organism isolated from wound is non lactose fermented and produced swarming growth on blood agar medium. Gram stain appeared as Gram-negative bacilli.

Figure 3

What is the presumptive identification of an organism in Figure 3?

(A) Echerichia coli

(B) Proteus vulgaris*

(D) Klebsiella pneumoniae

17. The selective media for the isolation of Salmonella typhi is

(A) blood agar

(B) MacConkey agar*

(D) deoxycholate citrate agar

18.

An organism isolated from wound is lactose fermented and produced Gram-negative bacilli, non-motile, capsulated and mucoid colonies appeared on blood agar.

Figure 4

What is the presumptive identification of an organism in Figure 4?

(A) Echerichia coli

(B) Bacillus subtilis

(D) Staphylococcus aureus

19. All of the following characteristics describe the genus Mycobacterium EXCEPT that it

(A) is an acid-fast

(B) is an obligate anaerobe

(D) has high cell wall lipid content*

20. Dorset Egg and Lowenstein-Jensen medium are enriched media which is used to isolate

(A) Neisseria gonorrhoeae

(B) Haemophilus influenzae

(D) Corynebacterium diphtheriae

21. What the disease cause by Mycobacterium leprae?

(A) Malaria

(B) Syphilis

(D) Tuberculoid Leprosy*

22. What type of sample can be used to diagnosis Mycobacterium tuberculosis?

(A) Urine

(B) Feces

(D) Nail clippings

23.

Gram positive branching or diphteroid-like bacilli, do not form endospores, Anaerobic and require CO2 for growth, Will grow on anaerobic Blood agar, slow growing. morphologically colonies form fungus-like branched networks of hyphae.

Figure 5

What is the presumptive identification of an organism in Figure 5?

(A) Enterobacter

(B) Actinomycetes*

(D) Campylobacter

24. Treponema pallidum can be demonstrated by

(A) Indian ink

(B) Gram stain

(D) Dark fluid examination*

25.

Elongated, motile, spiral bacteria, Gram-negative, Seen under Dark Ground Microscope

Figure 6

What is the presumptive identification of an organism in Figure 6?

(A) Echerichia coli

(B) Shigella dysenteriae

(D) Mycobacterium tuberculosis

26. Which disease is detected by the Rapid Plasma Reagin (RPR) test?

(A) Leprosy

(B) Syphilis*

(D) Tuberculosis

27. Man normally get infected with Mycoplasma pneumonia through

(A) ingestion of eggs in the food

(B) close contact via aerosolized droplets*

(D) Anopheles mosquito injects promastigotes into the skin

28. What the disease cause by Chlamydia trachomatos?

(A) Malaria

(B) Chancroid

(D) Lymphogranuloma venereum*

29.

In Gram staining, large square ended gram positive rods, may appear end to end giving a bamboo appearance.

Figure 7

What is the presumptive identification of an organism in Figure 7?

(A) Bacillus antracis*

(B) Actinomyces israeli

(D) Listeria monocytogenes

30. Which of the following staining techniques is commonly used to identify Corynebacterium diphtheriae?

(A) spore stain

(B) Albert stain*--blood agar, gram stain, Loeffler's serum slope

(D) negative stain

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. a. Draw and name morphology of bacteria according to shape. (4 Marks)

b. Explain the general steps in diagnostic isolation and identification of bacteria. (6 Marks)

2. a. Describe the general characteristics of Salmonella species. (4 Marks)

Gram - rods

Facultative anaerobe

Oxidase -

Lactose -

Glucose +

Most produce H2S

b. Explain the laboratory identification of typhoid fever. (6 Marks)

Salmonella enteriditis

MacConkey: clear colorless

DSI: red slant, yellow butt, black H2S

Confirm with entertube

3. Describe briefly the general characteristics and important properties Mycobacterium TB (10 marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

Discuss and draw the schematic diagram for the identification of Staphylococcus and Streptococcus species. (20 Marks)

Question 2

Describe the important properties of Haemophilus influenzae in term of gram staining reaction, morphological characteristics and laboratory diagnosis. (20 Marks)

Question 3

Discuss general features and laboratory diagnosis of Escherichia coli. (20 Marks)

January 2015

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. The oval shaped bacteria are known as

(A) cocci

(B) bacilli

(D) coccobacilli*

2. Bacteria A is cultured in Phenol Red Fermentation Broth and the medium in the

test tubes change colour from red to yellow. The bacteria A is

(A) aerobic

(B) oxidative

(D) microaerophilic

3. What would be the final colour of Gram stained for Gram Negative bacteria if the decolorizing step is done properly?

(A) pink*

(B) white

(D) yellow

4. Which of the following organism will give beta hemolysis on blood agar?

(A) Staphylococcus aureus

(B) Streptococcus agalactiae*

(D) Staphylococcus epidermidis

5. Staphylococcus aureus can be differentiated from Staphylococcus saprophyticus using the following test

(A) oxidase

(B) catalase

(D) novobiocin

6. A culture from a newborn with pneumonia reveals the following characteristics:

Figure 1

From the results on the Figure 1, what is the most likely organism responsible?

(A) Streptococcus viridans*

(B) Streptococcus pyogenes

(D) Staphylococcus saprophyticus

7. The colonies are small, opaque and complete lysis of the red blood cells surrounding a colony on blood agar plates. The colonies are probably

(A) beta streptococci*

(B) delta streptococci

(D) gamma streptococci

Figure 2

Organism "X" isolated from a cebrospinal fluid appeared as gram negative diplococci. The organism metabolizes glucose, maltose and is oxidase positive. The organisms did not metabolizes sucrose and can growth on New York City Agar.

8. What is the presumptive identification of organism "X" on Figure 2?

(A) Neisseria meningitidis*

(B) Neisseria gomorrhoea

(D) Pseudomonas aeruginosa

9. Culture on Modified Thayer Martin (MTM) medium of a vaginal swab produced several colonies of diplococci that were oxidase positive.

Figure 3

Given the following carbohydrate reactions, select the most likely causative organism on Figure 3.

(A) Bacillus anthracis

(B) Neisseria meningitidis

(D) Mycobacterium tuberculosis

Figure 4

10. What is the presumptive identification of genus on Figure 4?

(A) Proteus

(B) Klebsiella

(D) Corynebacterium*

11. Which of the following medium is a transport media to Vibrio spp?

(A) Nutrient agar

(B) Normal saline water

(D) Venkatraman-Ramakrishnan medium*

12. A organism "Y" which can culture on Chocolate agar medium, a Gram- negative bacilli, actively motile, oxidase positive, urease positive, oxidase positve and identified by Biopsy Urease test and Urea Breath test.

What is the presumptive identification of organism "Y" on Figure 5?

(A) Vibro cholerae

(B) Helicobacter pylori*

(D) Propionibacterium granulosum

13. Which of the following organisms requires both "X" and "V" factors for growth?

(A) Haemophilus ducreyi

(B) Haemophilus aegyptius*

(D) Haemophilus parahaemolyticus

14. Chocolate agar is used for the isolation of Haemophilus species because it provides the organism with

(A) beta aminolevulinic acid and hematin

(B) heme group and polyribose ribotol phosphate

(D) alpha aminolevulinic acid and nicotinamide adenine dinucleotide

15. All Enterobacteriaceae share the following characteristic which is

(A) Gram-positive

(B) ferment glucose*

(D) ferment maltose

16. Which of the following is TRUE about Proteus mirabilis?

(A) Lactose fermented

(B) Gram-positive bacilli

(D) Produce swarming growth on blood agar medium*

17. The Salmonella enterica

(A) is oxidise positive

(B) is lactose fermented

(D) can produce hydrogen sulfida*

Figure 6

An organism "Z" isolated from wound is lactose fermented and produced Gram-negative bacilli, non-motile, capsulated and mucoid colonies appeared on blood agar.

18. What is the presumptive identification of this organism "Z" on Figure 6?

(A) Echerichia coli

(B) Bacillus subtilis

(D) Staphylococcus aureus

19. What type of sample can be used to diagnosis Mycobacterium tuberculosis?

(A) hair

(B) urine

(D) sputum*

20. What microbe can cause Leprotamous leprosy?

(A) Mycobacterium leprae*

(B) Neisseria gonorrhoeae

(D) Mycobacterium tuberculosis

21. All of the following enriched media are used to isolate Mycobacterium tuberculosis EXCEPT

(A) Dorset Egg

(B) Nutrient agar*

(D) Lowenstein-Jensen medium

22. Which of the following stain is required to prepare smear of sputum suspected of Mycobacterium tuberculosis?

(A) Indian ink

(B) Gram stain

(D) Acid fast stain*

23. Which of the following organisms is the aetiological agent for acne?

(A) Actinomyces species

(B) Staphylococcus species

(D) Propionibacterium species*

24. Treponema pallidum can be demonstrated by

(A) Indian ink

(B) Gram stain

(D) Dark field microscopy*

25. All of the following characteristics are describe about Leptospira interrogans EXCEPT

(A) motile

(B) Gram-positive*

(D) seen under dark ground microscope

26. Which disease is detected by the RPR (Rapid Plasma Reagin) test?

(A) leprosy

(B) syphilis*

(D) tuberculosis

27. Which of the following is NOT TRUE about Mycoplasma pneumoniae?

(A) gram positive cocci

(B) can be stained with Dienes stain

(D) can be transmitted to close contact via Anopheles mosquito

28. Which of the following staining techniques is commonly used to identify Chlamydia trachomatos?

(A) Gram stain

(B) Giemsa stain*

(D) Acid-fast stain

29. Which of the following staining techniques is commonly used to identify Corynebacterium diphtheriae?

(A) Albert stain*

(B) Acid fast stain

(D) Haematoxylin-Eosin stain

30. What the disease cause by Chlamydia trachomatos?

(A) Malaria

(B) Chancroid

(D) Lymphogranuloma venereum*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. a. Describe the characteristics of Staphylococcus aureus. (5 Marks)

b. Describe the laboratory identification of Streptococcus pyogenes. (5 Marks)

2. a. Determine the general characteristics of Bacillus anthracis. (5 Marks)

b. Explain the laboratory confirmatory diagnosis on the anthrax. (5 Marks)

3. a. Describe the general characteristics of Haemophilus influenzae. (4 Marks)

b. Distinguish between Streptococcus pneumoniae, Neisseria gonorrhoeae and Haemophilus influenzae based on Gram stain and morphological characteristics? (6 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

Describe SEVEN (7) basic biochemical tests. State the purpose and the principle of the test. (20 Marks)

Question 2

Explain the general characteristics, important properties and laboratory diagnosis of Mycobacterium tuberculosis. (20 Marks)

Question 3

Discuss general features and laboratory diagnosis of Shigella boydii. (20 Marks)

August 2014

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

CHOOSE ONE BEST STATEMENT TO ANSWER THE QUESTIONS

1. Streptococcus are Gram positive cocci that tend to grow in

(A) pairs

(B) single

(D) clusters

2. In Oxidation-Fermentation (O-F) test, if the medium in the test tubes change colour from green to yellow. The causative agent is

(A) aerobic

(B) oxidative

(D) microaerophilic

3. What would be the final colour of Gram stained bacteria if the decolorizing step is not done properly?

(A) Pink

(B) White

(D) Yellow

4. Which of the following organisms will give positive reaction in the coagulase test?

(A) Staphylococcus aureus*

(B) Streptococcus pyogenes

(D) Staphylococcus epidermidis

5. Staphylococcus epidermidis can be differentiated from Staphylococcus saprophyticus using the following test:

(A) oxidase

(B) catalase

(D) novobiocin*

6. A throat swab sample onto a fresh blood agar plate and the results shown in a heavy growth of beta haemolysis is MOST likely to be due to

(A) Streptococcus viridans

(B) Haemophilus influenza

(D) Streptococcus pyogenes*

7. The colonies are small, greyish, opaque and are surrounded by a well-defined zone of hemolysis on blood agar plates. The colonies are probably

(A) beta streptococci*

(B) delta streptococci

(D) gamma streptococci

Organism "X" isolated from a vaginal swab appeared as gram negative diplococci. The organism metabolizes only glucose and is oxidase positive.

What is the presumptive identification of organism "X"?

(A) Neisseria lactamica

(B) Neisseria gomorrhoea*

(D) Pseudomonas aeruginosa

(A) Bacillus anthracis

(B) Neisseria meningitidis*

(D) Mycobacterium tuberculosis

10.

"Gram-positive rod-like forms", may appear end to end giving a bamboo appearance arrangement, the colonies on blood agar is non hemolytic on 5% blood agar, raised large and grayish white. Identify organism which is defined as

(A) Escherichia coli

(B) Bacillus anthracis*

(D) Staphylococcus aureus

11. Which of the following medium is NOT a transport media to Vibrio spp?

(A) Cary-Blair medium

(B) Loeffler’s serum slope*

(D) Venkatraman-Ramakrishnan medium

12. A bacteria which can culture on Skirrow’s medium, a Gram-negative bacilli, actively motile, oxidase positive and identified by failure to grow at 25 °C is

(A) Vibro cholerae

(B) Echerichia coli

(D) Propionibacterium granulosum

13. The colonies that exhibit satellite formation near colonies of staphylococci belong to

(A) Neissena meningitidis

(B) Neissena gonorrhoeae

(D) Streptococcus agalactiae

14. Which of the following is NOT TRUE regarding Haemophilus ducreyi?

(A) It requires growth factor.

(B) It does not require factor X.*

(D) It is a Gram-negative pleomorphic bacilli.

15. All Enterobacteriaceae share all of the following characteristics EXCEPT

(A) Gram-negative

(B) ferment glucose

(D) reduce nitrates to nitrites

16. Which of the following is NOT TRUE about Proteus mirabilis?

(A) Non lactose fermented

(B) Gram-negative bacilli

(D) Produce swarming growth on blood agar medium

17. The Shigella boydii

(A) is motile

(B) is lactose fermented

(D) can produce hydrogen sulfida

18. Identify the bacteria may produces very powerful urease, catalase and is oxidase positive. They can also cause gastric ulcer.

(A) Echerichia coli

(B) Vibrio Cholerae

(D) Campylobacter jejuni

19. Which of the following stain is required to prepare a direct smear of sputum suspected of Mycobacterium tuberculosis?

(A) Indian ink

(B) Gram stain

(D) Carbol fuchsin

20. What microbe can cause Tuberculoid Leprosy?

(A) Mycobacterium leprae*

(B) Neisseria gonorrhoeae

(D) Mycobacterium tuberculosis\

21. Lowenstein-Jensen medium are enriched media which is used to isolate

(A) Neisseria gonorrhoeae.

(B) Haemophilus influenzae.

(D) Corynebacterium diphtheriae.

22. Which of the following stain is required to prepare smear of skin suspected of Mycobacterium leprae?

(A) Indian ink

(B) Gram stain

(D) Acid fast stain*

23. Physician ordered a set of three blood cultures drawn on his patient. After 48 hours of incubation, one of the bottles was positive for Propionibacterium acnes while the other two remained negative.

What is the most likely explanation for this observation?

(A) The patient has sepsis.

(B) The two negative bottles belonged to another patient.

(D) Propionibacterium acnes are skin contaminants due to improper venipuncture technique.

24. Treponema pallidum can cause

(A) syphilis*

(B) meningitis

(D) tuberculosis

25. All of the following characteristics are describe about Leptospira interrogans EXCEPT

(A) motile

(B) Gram-positive*

(D) seen under dark ground microscope

26. Which disease is detected by the Venereal Disease Research Laboratory test?

(A) leprosy

(B) syphilis*

(D) tuberculosis

27. Which of the following is NOT TRUE about Mycoplasma pneumoniae?

(A) resemble fried eggs

(B) can be stained with Dienes stain

(D) can be transmitted to close contact via aerosolized droplets

28. Which of the following staining techniques is commonly used to identify Chlamydia trachomatos?

(A) Gram stain

(B) Diene’s stain

(D) Acid-fast stain

29. Identify the bacteria of large Gram-positive rods with square ends, found in chains, non-motil, its antiphagocytic capsule is composed of D-glutamate and cause anthrax.

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30. Tellurite medium is normally used to isolate

(A) Neisseria gonorrhoeae.

(B) Staphylococcus aureus.

(D) Corynebacterium diphtheriae.*

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

ANSWER ALL QUESTIONS

1. a. Name the organism suspected of causing the cholera outbreak. (2 Marks)

b. Explain the laboratory diagnosis on the cholera outbreak and state the type of specimen received. (8 Marks)

2. a. Identify the etiological agent cause meningitis. (2 Marks)

b. Explain the laboratory confirmatory diagnosis on the meningitis. (8 Marks)

3. a. Describe the general characteristics of Mycobacterium tuberculosis. (5 Marks)

b. Determines the important properties of Mycobacterium tuberculosis. (5 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

ANSWER TWO (2) QUESTIONS ONLY

Question 1

With the aid of diagram, discuss of identification of Staphylococcus and Streptococcus species. (20 Marks)

Question 2

Explain important properties of Haemophilus influenzae including staining and morphological characteristics and laboratory diagnosis. (20 Marks)

Question 3

Discuss general features and laboratory diagnosis of Klebsiella pneumoniae. (20 Marks)

January 2014

PART A: MULTIPLE CHOICE QUESTIONS (30 MARKS)

Choose ONE best statement to answer the questions.

1. The bacterial species that has cocci in chain is

(A) Streptococcus spp.*

(B) Pneumococcus spp.

(D) Corynebacterium spp.

2. A known culture of Salmonella typhi appears pink in Gram stain and bacilli in shape. This result could be

(A) incorrect as the bacteria are not bacilli

(B) correct as the bacteria is Gram negative*

(D) correct because the bacteria show variability in colour and shape

3. In slide preparation for staining, what is the process that allows the bacterial cells to adhere to the glass slide?

(A) fixation*

(B) smearing

(D) decolourization

4. By definition, a bacterial isolate is Staphylococcus aureus if it

(A) ferments glucose

(A) produces coagulase*

(B) produces free catalase

5. Which of the following statement is TRUE?

(A) Staphylococcus pyogens is resistant to 5µg bacitracin.

(B) Streptococcus viridans produces gamma hemolysis on blood agar.*

(D) Novobiocin test is used to differentiate Staphylococcus epidermidis from Staphylococcus saprophyticus.

6. Staphylococcus aureus can be differentiated from Streptococcus pyogenes using the following test

(A) motility

(B) catalase*

(D) coagulase

7. The Lancefield grouping of Streptococcus pyogenes is a

(A) Lancefield Group A*

(B) Lancefield Group B

(D) Lancefield Group D

8. Which of the following is TRUE about Neisseria gonorrhoea?

(A) It is a Gram positive

(B) It can produce oxidase*

(D) It metabolizes maltose and sucrose

9. Culture on Modified Thayer Martin (MTM) medium of a vaginal swab produced several colonies of Gram-negative diplococci that are oxidase positive. Given the following carbohydrate reactions. In the table 1, select the most likely causative organism.

(A) Salmonella enteric

(B) Moraxella catarrhalis

(D) Corynebacterium diphteriae

10. Tellurite medium is normally used to isolate

(A) Staphylococcus aureus

(B) Neisseria gonorrhoeae

(D) Corynebacterium diphtheriae*

11. Which of the following medium is NOT a transport media for Vibrio cholera?

(A) Cary-Blair Medium

(B) Loeffler’s serum slope*

(D) Venkatraman-Ramakrishnan medium

12. A bacteria which can be cultured on Skirrow’s medium, Gram-negative bacilli, actively motile, oxidase positive and identified by failure to grow at 25 °C is

(A) Vibro cholerae

(B) Echerichia coli

(D) Propionibacterium granulosum

13. Which of the following organisms requires "X (haemin)" factors for growth?

(A) Haemophilus ducreyi*

(B) Haemophilus influenza

(D) Haemophilus parahaemolyticus

14. The colonies that exhibit satellite formation near colonies of staphylococci belong to

(A) Shigella boydii

(B) Streptococcus pyogens

(D) Neisseria gonorrhoeae

15. All Enterobacteriaceae share all of the following characteristics EXCEPT

(A) Gram negative

(B) ferment glucose

(D) reduce nitrates to nitrites

16. Which of the following is FALSE about Proteus vulgaris?

(A) A Gram-negative bacilli

(B) A non lactose fermenting organism

(D) An organism can produced swarming growth on blood agar medium

17. The Shigella boydii

(A) is motile

(B) can produce gas

(D) is a glucose fermenting organism*

18.

An organism isolated from urine is non lactose fermenting, Gram-negative bacilli, motile, capsulated and appeared as swarming growth colonies on blood agar.

Figure 1

What is the presumptive identification of the organism described in figure 1?

(A) Proteus mirabilis*

(B) Moraxella catarrhalis

(D) Klebsiella pneumoniae

19. Which of the following is the characteristic genus Mycobacterium?

(A) is a cocci

(B) is a motile

(D) has high cell wall lipid content*

20. Dorset Egg and Lowenstein-Jensen medium are enriched media which is used to isolate

(A) Bacillus anthracis

(B) Salmonella bongori

(D) Mycobacterium tuberculosis*

21. The growth of Mycobacterium tuberculosis in the laboratory will normally take between

(A) 4-6 days

(B) 4-6 hours

(D) 4-6 month

22. Which of the following stain is required to prepare smear of sputum suspected of Mycobacterium leprae?

(A) Indian ink

(B) Gram stain

(D) Acid fast stain*

23. Which of the following organisms is the aetiological agent for acne?

(A) Actinomyces species

(B) Staphylococcus species

(D) Propionibacterium species*

24. Treponema pallidum can cause

(A) syphilis*

(B) meningitis

(D) tuberculosis

25. Which of the following characteristic describe the Leptospira interrogans?

(A) non motile

(B) cocci bacteria

(D) seen under Dark Ground Microscope*

26. Which disease is detected by the Wasserman complement fixation test?

(A) Leprosy

(B) Syphilis*

(D) Tuberculosis

27. Which of the following is TRUE about Mycoplasma pneumoniae?

(A) It can be stained with Dienes stain*

(B) It’s normal flora in the human lungs

(D) It cannot hemolyze guinea pig red blood cells

28. Which of the following staining techniques is commonly used to identify Chlamydia trachomatis?

(A) Gram stain

(B) Diene’s stain

(D) Acid-fast stain

29.

When stained this organism is large, gram positive rods with square end, found in chains, non motile and has antiphagocytic capsule composed of D-glutamate. It’s causes anthrax.

Figure 2

What is the presumptive identification of the organism described in figure 2?

(A) Bacillus antracis*

(B) Campylobacter jejuni

(D) Listeria monocytogenes

30. Which of the following staining techniques is commonly used to identify Corynebacterium diphtheriae?

(A) Albert stain*

(B) Acid fast stain

(D) Haematoxylin-Eosin stain

PART B: SHORT ANSWER QUESTIONS (30 MARKS)

Answer ALL questions.

1. a. Draw and name morphology of bacteria according to shape. (6 Marks)

b. Briefly explain the general steps in diagnostic isolation and identification of bacteria. (4 Marks)

2. a. Determine FOUR (4) basic biochemical tests. (2 Marks)

b. Briefly explain the purpose and the principle of FOUR (4) basic biochemical tests. (8 Marks)

3. a. Determine the general characteristics of the Escherichia Coli. (5 Marks)

b. Briefly describe the laboratory diagnosis to detect Klebsiella pneumoniae. (5 Marks)

PART C: ESSAY QUESTIONS (40 MARKS)

Answer TWO (2) questions only.

Question 1

Discuss and draw the schematic diagram for the identification Streptococcus species and describe the appearances of alpha, beta and gamma haemolysis on blood agar.

Give ONE (1) example of an organism for each of the haemolysis. (20 marks)

Question 2

Describe the general characteristics, method of acquiring and laboratory investigation of Salmonella enterica. (20 marks)

Question 3

Describe important properties of Haemophilus influenzae including staining and morphological characteristics and laboratory investigation. (20 Marks)

August 2013

SECTION A : OBJECTIVE QUESTIONS (30 MARKS)

Choose ONE best statement to answer the questions.

1. Which of the following are the BEST to growth of Gram negative bacteria?

(A) blood agar*

(B) mac conkey*

(D) eosin methylene blue agar

2. Staphylococcus aureus is

(A) catalase positive

(B) coagulase negative

(D) the cause factor food poisoning*

3. Pyrogenic is a term for

(A) pus inducement

(B) fever inducement*

(D) acute glomerular nephritis

4. Which of the following is NOT considered as infection caused by Streptococcus pyogenes?

(A) cellulitis

(B) impetigo

(D) food poisoning*

5. What is the O antigen of Enterobacteriaceae?

(A) a flagellar protein.

(B) cell surface polysaccharide.*

(D) a peptidoglycan matrix important for cellular rigidity.

6. Identify the component which is MOST associated with the induction of septic shock caused by Gram positive bacteria cell.

(A) endotoxin

(B) peptidoglycan*

(D) capsular protein

7. The gram staining is NOT useful in the preliminary identification of

(A) Mycobacterium leprae*

(B) Legionella pneumophilia

(D) Cornebacterium diptheriae

8. The coagulase test is used to differentiate Staphylococcus aureus from

(A) enterococci species

(B) micrococci species

(D) other Staphylococcus species*

9. The single MOST important characteristic of diarrhea caused by Vibrio cholera is

(A) renal insufficiency

(B) severe abdominal pain

(D) profound watery diarrhea*

10. Which of the following virulence factors of Escherichia coli is important for attachment to host epithelial cells in the pathogenesis of urinary tract infections?

(A) pili

(B) urease

(D) alpha hemolysin

11. Which of the following microorganism causes scarlet fever?

(A) Streptococcus pyogenes*

(B) Staphylococcus aureus

(D) Pseudomonas aeruginosa

https://microbeonline.com/mcq-microbiology-bacteriology-bacterial-skin-infections/

12. Anaerobic infections are

(A) cause by Gram positive bacteria

(B) often continuous to mucosal surfaces*

(D) most likely to occur in the lung with its high oxygen level

13. Which of the following is negative production of catalase?

(A) Proteus spp.

(B) Salmonella spp.

(D) Staphylococcus spp.

14. Which of the following are NOT primary pathogens or organisms capable of causing disease in human?

(A) Salmonella spp.

(B) Shigella spp.

(D) Proteus spp.*--serratia, enterobacter, morganella, providencia

15.

An organism isolated from lung abscess is a gram negative bacilli, short and not motile and capsulate.

What is the presumptive identification of this organism?

(A) Escherichia coli*

(B) Bacillus subtilis

(D) Klebsiella pneumonia

16. Virulence factors of Escherichia coli

(A) contain clumping factor

(B) is the abilities in motility

(D) is the ability to adhere and produce endotoxin*

17. A throat swab sample was sent to the lab with orders to do an anaerobic culture.

What is the BEST action of staff to proceed?

(A) set culture immediately

(B) sent swab to a reference lab for culture

(D) reject specimen as inappropriate for anaerobic culture and call physician to further discuss orders*

https://quizlet.com/146094168/microbiology-specimen-collection-transport-processing-preliminary-identification-methods-flash-cards/

18. Which of the following statements about group B Streptococci (Streptococci agalactiae) is FALSE?

(A) beta hemolytic organisms

(B) cause of toxic streptococcus syndrome*--pyogenes

(D) screening for this pathogen during pregnancy has reduced the incidence of neonatal sepsis

19. Failure to respond of antimicrobial therapy in pneumonia is due to

(A) host factors

(B) incorrect diagnosis

(D) inappropriate choice of antibiotics*

20. Which of the following is TRUE about Salmonella typhi?

(A) cause enteric fever*

(B) sensitive to tetracycline

(D) is a saprophyte found in environmental sources

21. A common characteristic of Neisseria gonorrhea is

(A) to cause syphilis

(B) it is a gram positive cocci--negative

(D) it can be transmitted only by sexual route*

22. The presence of bacteria in the blood is termed

(A) toxemia

(B) bacterimia*

(D) secondary infection

23. Which of the following organisms is the common cause of urinary tract infection?

(A) Escherichia coli*

(B) Proteus mirabilis

(D) Klebsilla pneumonia

24.

A quality control gram stain smear was prepared using 18 hour old culture of Escherichia coli. On microscopic examination of the gram stained smear, the organisms appear blue.

What is the possible cause of these organisms?

(A) over decolorized

(B) under decolorized*

(D) probably too young to properly gram stain

25.

A 5 year old boy in the pediatric respiratory clinic has productive cough and a specimen is forwarded to the laboratory. Select the culture medium which would be MOST appropriate to isolate Haemophilus influenza from this patient.

(A) XLD agar

(B) blood agar*

(D) mac conkey agar

26. This urinary pathogen “swarms” across agar surface and may cause bladder and renal calculi.

What type of organism that suitable with the statement above?

(A) Proteus mirabilis*

(B) Klebsiella oxytoca

(D) Enterobacter aerogenes

27.

According to the picture at above, gas gangrene is most likely associated with infection with

(A) Neisseria gonorrhoeae

(B) Clostridium perfringenes*

(D) Pseudomonas aeruginosaa

28. Which of the following bacteria are MOST likely to cause meningitis during the first 2 years of life?

(A) N.fowleri

(B) H. influenzae

(D) M. tuberculosis

29. Each of the following statements concerning the normal flora is correct EXCEPT

(A) the major site where Bacteroides fragilis is found in the colon

(B) the most common organism found on the skin is Staphylococcus epidermidis

(D) one of the most common sites where Staphylococcus aureus is found in the nose

30. Each of the following statements concerning Mycobacterium tuberculosis is correct EXCEPT

(A) M. tuberculosis appears as a red rod in gram stained specimen*

(B) M. tuberculosis has large amount of mycolic acid in its cell wall

(D) after being stained with carbolfuschin, M. tuberculosis resists decolorization with acid alcohol

SECTION B : SHORT ANSWER QUESTIONS (30 MARKS)

Answer ALL questions.

1. a. Differentiate between opportunistic and primary pathogen and give an example for each category. (6 Marks)

b. Name the types of media that is contained in the double sugar iron agar slant. (4 Marks)

2. a. Name the antigenic structure of Salmonella species that can be used for bacterial identification. (6 Marks)

b. List FOUR (4) major diseases that are caused by Salmonella species. (4 Marks)

3. a. Determine the most important pathogen species and its related disease to human caused by Vibrio sp.. (6 Marks)

b. State the methods to control Campylobacter sp. spread to other humans. (4 Marks)

SECTION C : ESSAY QUESTIONS (40 MARKS)

Answer TWO (2) questions only.

Question 1

Describe in detail the morphology and basic features of Escherichia coli. Elaborate the laboratory diagnosis of Escherichia coli. (20 Marks)

Question 2

Scalded skin syndrome is caused by bacterial infections where it can produce blister and redness on the skin. Discuss in detail the laboratory techniques that used in identifying these organisms. (20 Marks)

Question 3

Discuss in detail at least FOUR (4) the principles, purpose and techniques that are used in the laboratory for bacterial identification. (20 Marks)

January 2013

SECTION A: OBJECTIVE QUESTIONS (30 MARKS)

Choose ONE best statement to answer the questions.

1. The bacterial species that has cocci in clusters is

(A) Streptococcus spp.

(B) Staphylococcus spp.*

(D) Corynebacterium spp.

2. A known culture of Micrococcus appears purple in Gram stain and coccus in shape. This result could be

(A) incorrect as the bacteria are not cocci.

(B) correct as the bacteria is Gram positive.*

(D) correct because the bacteria show variability in colour and shape.

3. What would be the final colour of Gram stained bacteria if the decolorizing step is done properly for gram negative bacteria?

(A) pink*

(B) purple

(D) yellow

4. Identify the statement which is NOT TRUE.

(A) Streptococcus pneumonia is resistant to 5ug optochin.

(B) Staphylococcus epidermidis is susceptible to 5ug novobiocin.

(D) Catalase test is used to differentiate Staphylococcus from Streptococcus.

5. The Lancefield grouping of streptococci is based on the

(A) proteins found in cell walls*

(B) precipitation of cell wall fat

(D) production of various haemolytic enzymes

6. The CAMP test is used as a presumptive test to identify

(A) Klebsiella pneumonia

(B) Enterobacter aerogenes

(D) Streptococcus agalactiae*

7. Staphylococcus aureus can be differentiated from Staphylococcus epidermidis using which of the following test?

(A) motility

(B) catalase

(D) coagulase*

8. An organism isolated from a vaginal swab is oxidase-positive and on Gram stain appeared as Gram-negative diplococci. The organism metabolizes only glucose.

What is the presumptive identification of this organism?

(A) Campylobacter jejuni

(B) Neisseria gonorrhoeas*

(D) Staphylococcus saprophyticus

9. Culture on Modified Thayer Martin (MTM) medium of a vaginal swab produced several colonies of Gram-negative diplococci that were oxidase positive. Given the following carbohydrate reactions, select the most likely causative organism.

(A) Escherichia coli

(B) Helicobacter pylori

(D) Neisseria gonorrhoeae*

10. The genus for the group of organisms which is defined as "gram-positive rod-like forms", has a characteristic "Chinese letter" arrangement; often with club-shaped swellings at the poles with irregularly staining segments or granules is

(A) Proteus

(B) Klebsiella

(D) Corynebacterium*

11. Which of the following medium is MOST suitable to culture Vibrio spp?

(A) MAC agar

(B) XLD agar

(D) CLED agar

12. A bacteria which produces a very powerful urease, catalase and oxidase positive and also can cause gastric ulser is

(A) Shigella boydii

(B) Proteus vulgaris

(D) Streptococcus viridans

13. Which of the following organisms requires both "X" and "V" factors for growth?

(A) Haemophilus ducreyi

(B) Haemophilus influenza*

(D) Haemophilus parahaemolyticus

14. Which of the following is NOT TRUE regarding Haemophilus parainfluenzae?

(A) it requires growth factor.

(B) it does not require factor V.*

(D) it is gram negative pleomorphic bacilli.

15. Which of the following bacteria species is negative for oxidase test?

(A) Shigella flexneri*

(B) Campylobacter jejuni

(D) Pseudomonas aeruginosa--oxidase +

An organism isolated from wound is non lactose fermented and produced swarming growth on blood agar medium. Gram stain appeared as Gram-negative bacilli.

16. What is the presumptive identification of this organism?

(A) Proteus mirabilis*

(B) Salmonella enteritidis

(D) Klebsiella pneumonia

17. The selective media for the isolation of Salmonella typhi is

(A) blood agar

(B) nutrient agar

(D) Lowenstein-Jensen agar

An organism isolated from wound is lactose fermented and produced Gram-negative bacilli, non-motile, capsulated and mucoid colonies appeared on blood agar.

18. What is the presumptive identification of this organism?

(A) Moraxella catarrhalis

(B) Listeria monocytogens

(D) Staphylococcus saprophyticus

19. All of the following are the characteristic genus Mycobacterium EXCEPT

(A) it is an acid-fast.

(B) it is an obligate anaerobe.

(D) it has high cell wall lipid content.*

20. Dorset Egg and Lowenstein-Jensen medium are enriched media which is used to isolate

(A) Bacillus anthracis

(B) Actinomyces israelii.

(D) Mycobacterium tuberculosis.*

21. What is the disease caused by Mycobacterium leprae?

(A) chancroid

(B) leishmaniasis

(D) lymphogranuloma venereum

22. What is the type of sample used in the diagnosis Mycobacterium tuberculosis?

(A) hair

(B) urine

(D) sputum*

Gram positive branching or diphteroid-like bacilli, do not form endospores, anaerobic and require CO2 for growth, will grow on anaerobic blood agar, slow growing, morphologically colonies form fungus-like branched networks of hyphae.

23. What is the presumptive identification of this organism?

(A) Serratia

(B) Enterobacter

(D) Mycobacterium

24. Treponema pallidum can be demonstrated by

(A) Gram stain

(B) dark fluid examination*

(D) Warthin-starry silver stain

Elongated, motile, spiral bacteria, Gram-negative, seen under Dark Ground Microscope.

25. What is the presumptive identification of this organism?

(A) Leptospira interrogans*

(B) Enterobacter aerogenes

(D) Corynebacterium diphtheria

26. Which of the following diseases is detected by the Rapid Plasma Reagin (RPR) test?

(A) Malaria

(B) Leprosy

(D) Genital herpes

27. Man would normally get infected with Mycoplasma Pneumoniae through

(A) ingestion of larva in the water

(B) close contact via aerosolized droplets*

(D) Aedes mosquito injects trypomastigotes into the skin

28. What is the disease caused by Chlamydia trachomatos?

(A) Warts

(B) Vaginitis

(D) Lymphogranuloma venereum*

In Gram staining, large square ended gram positive rods, may appear end to end giving a bamboo appearance.

29. What is the presumptive identification of this organism?

(A) Bacillus antracis*

(B) Klebsiella pneumonia

(D) Vibro parahaemolyticus

30. Which of the following staining techniques is commonly used to identify Corynebacterium diphtheriae?

(A) Albert stain*

(B) Acid fast stain

(D) Haematoxylin-Eosin stain

SECTION B: SHORT ANSWER QUESTIONS (30 MARKS)

Answer ALL questions.

1. Describe the species of Haemophilus aegyptius based on the following topics:

a. Staining characteristics of Haemophilus aegyptius. (2 Marks)

b. Morphology of Haemophilus aegyptius. (3 Marks)

c. Diseases caused by Haemophilus aegyptius. (5 Marks)

2. a. Determine the general characteristics of Klebsiella pneumoniae. (5 Marks)

b. Describe the laboratory diagnosis to detect Escherichia Coli. (5 Marks)

3. a. Explain the laboratory identification of typhoid fever. (6 Marks)

b. Describe the general characteristics of Salmonella species. (4 Marks)

SECTION C: ESSAY QUESTIONS (40 MARKS)

Answer TWO (2) questions only.

Question 1

Explain SEVEN (7) basic biochemical tests. State the purpose and the principle of each test. (20 Marks)

Question 2

Discuss and draw the schematic diagram for the identification of Staphylococcus and Streptococcus species. (20 Marks)

Question 3

Discuss the important properties of Mycobacterium tuberculosis including staining and morphological characteristics and laboratory diagnosis. (20 Marks)

2/2009/2010

PART A: OBJECTIVES QUESTIONS (30 Marks)

Choose the best option answer the questions.

1. Facultative anaerobes are bacteria, which are able to grow

A. in high concentration of oxygen.

B. with or without oxygen.*

C. in low concentration of oxygen.

D. without oxygen.

2. Which of the following microorganisms has NOT been linked to UTI's?

A. E. coli.*

B. Proteus mirabilis.

C. Klebsiella penumoniae.

D. Bacteroids fragilis.

3. Mycoplasmas are different from most other bacteria in that they have no

A. cell wall.*

B. cell membrane.

C. nucleic acid.

D. flagella.

4. Most cases of nongonococcal urethritis are caused by

A. Chlamydia trachomatis.*

B. Neisseria gonorhoea.

C. Treponema pallidum.

D. Staphylococcus aureus.

5. Guillain-Barre syndrome is associated with

A. Camplylobacter jejuni.*

B. Camplylobacter coli.

C. Helicobacter pylori.

D. Vibrio cholera.

6. A __________ infection is acquired in a hospital.

A. nosocomial*

B. zoonosis

C. focal

D. subclinical

7. Sepsis is a medical condition referring to the

A. systemic inflammatory response syndrome.*

B. presence of pathogenic organisms in the bloodstream.

C. inflammation of the protective membranes.

D. acute inflammation of the brain.

8. MacConkey agar contains the dye, crystal violet that inhibits the growth of Gram-positive bacteria and also contains lactose and a pH indicator that allow the detection of lactose fermenting bacteria. MacConkey agar is classified as

A. differential, selective.*

B. complex, sensitive.

C. differential.

D. enrich.

9. Penicillin

A. inhibit cell wall synthesis.*

B. inhibit protein synthesis.

C. inhibit nucleic acid synthesis.

D. inhibit metabolism activity.

10. _________________ is the capacity to produce disease

A. Pathogenecity*

B. Virulence

C. Attenuation

E. Passage

11. Each of the following statements concerning chlamydiae is correct EXCEPT

A. Chlamydiae are strict intracellular parasites.

B. they cannot synthesize sufficient ATP.

C. Chlamydiae possess both DNA and RNA.

D. most chlamydiae are transmitted by arthropods.

12. What is the most susceptible phase of growth for most microorganisms by an antimicrobial agent?

A. Lag phase.

B. Log phase.

C. Stationary phase.

D. Death phase.

13. Which of the following test results is correct for Bacillus anthracis?

A. Gram stain = Gram negative--positive

B. Motility = Non-motile*

C. Growth on PEMBA = Turqoise blue colonies

D. Hemolytic activity = Beta hemolysis--non hemolytic

14. The presence of a few, non multiplying, bacteria in the blood is termed

A. viremia.

B. septicemia.

C. bacterimia.*

D. sepsis.

15. Which of the following bacterial groups would you expect to be MOST likely associated with human infection?

A. Thermophiles.

B. Lactophiles.

C. Mesophiles.

D. Psychrophiles.

16. Salmonella typhi has the ability to persist within the gallbladder of human while causing no clinical symptoms. The infected individual is still contagious, however and would be considered a (n):

A. Pathogen.

B. Nuisance.

C. Endemic.

D. Carrier.

17. Each of the following statements concerning Gram-negative rods is correct EXCEPT

A. Escherichia coli is part of the normal flora of the colon; therefore, it does not cause diarrhea.

B. E. coli ferment lactose, whereas the enteric pathogens Shigella and Salmonella do not.

C. Klebsiella pneumoniae, although a cause of pneumonia, is part of the normal flora of the colon.

D. Proteus species are highly motile organisms that are found in the human colon and cause urinary tract infections.

18. The picture below shows a patient suffering from cervicofacial. The organism that MOST likely to cause this disease is

A. Eschirichia coli.

B. Nocardia asteroids.

C. Actinomycetes israelii.*

D. Treponerma pallidum.

19. An obligate psychrophile would produce a turbid culture at ________ degrees Celsius.

A. 15*

B. 30

C. 45

D. 60

20. Which one of the following organisms that infects the gastrointestinal tract is the MOST frequent cause of bacteremia?

A. Shigella flexneri.

B. Campylobacter jejuni.*

C. Vibrio cholerae.

D. Salmonella typhi.

21. Which of the following types of organisms is NOT an obligate intracellular parasite and therefore can replicate on bacteriologic media?

A. Chlamydia.

B. Mycoplasma.

C. Adenovirus.

D. Ricketsia.

22. Which of the following is FALSE regarding bacillus species

A. Bacillus subtilis cause food poisoning.

B. Bacillus anthracis cause anthrax.

C. Bacillus aureus cause food poisoning.

D. Bacillus producing spore.*--endospore

23. Which of the following types of organisms would be most likely found only in the large intestine, where there is a complete lack of free oxygen?

A. Obligate aerobe.

B. Obligate anaerobe.

C. Facultative anaerobe.*

D. Aerotolerant anaerobe.

24. Which of the following statements MOST accurately depicts the ability of the organism to be cultured in the laboratory?

A. Treponerma pallidum from a chancre can be grown on a special artificial medium supplemented with cholesterol.

B. Mycobacterium leprae can be grown in armadillo and the mouse foot pad but no on any artificial media.*

C. Mycobacterium tuberculosis can be grown on enriched artificial media and produces visible colonies in 48-96 h.

D. Atypical mycobacterium is found widely in soil and water but cannot be cultured on artificial media in the laboratory.

25. Blood agar is often used to observe changes in appearance of the agar around the colonies growing on this medium. This medium could then be called

A. selective.

B. differential.*

C. defined.

D. selective.

26. Bacillus cereus is most noted for causing

A. food poisoning.*

B. Meningitis.

C. Sexually transmitted disease.

D. Urinary tract infections.*

27. Which of the following organisms is MOST likely to be the cause of pneumonia in an immunocompetent patient?

A. Nocardia asteroids.

B. Serratia marcescens.

C. Mycoplasma pneumonia.*

D. Legionella pneumophilia.

28. Several pathogens are transmitted either during gestation or at birth. Which one of the following is LEAST likely to be transmitted at these times?

A. Haemophilus influenzae.

B. Treponema pallidum.*

C. Neiserria gonorrhea.

D. Chlamydia trachomatis.

29. Strict anaerobes, slow growing (5 to 14 days), and can grow at wide range of temperature refers to the characteristics of

A. Nocardia asteroids.

B. Chlamydia trachomatis.

C. Actinomycetes israelii.*

D. Haemophilus influenza.

30. Each of the following statement concerning Chlamydia trachomatis is correct EXCEPT

A. It is an important cause of nongonococcal urethritis.

B. It is the cause of lymphogranuloma venereum.

C. It is an important cause of subacute bacterial endocartitis.*

D. It is an important cause of conjunctivitis.

PART B. SHORT ANSWER QUESTIONS (40 Marks)

Answer ALL questions

1. List THREE (3) important properties of Gram-negative rod. (3 marks)

facultative anaerobes

ferment glucose

non spore forming

2. List FOUR (4) medically important pathogens in the group of enterobacteriacea. (4 marks)

Escherichia coli

Proteus vulgaris

Klebsiella penumonia

Shigella boydii

3. State special growth factors for Haemophilus sp. (4 marks)

X factor haemin

Y factor nicotinamide adenine dinucleotide (NAD)

4. Describe identification of gram-negative beginning with growth on MacConkey agar (use flow chart to aid your explanations) (5 marks)

5. State TWO (2) type of diseases that caused by Mycobacteria. (4 marks)

Tuberculosis

Tuberculoid leprosy

Leprotamous leprosy

6. List ONE (1) special media used to grow Camplylobacter samples. (1 mark)

Skirrow's medium

7. Describe TWO (2) type of non-cultural diagnosis of Helicobacter pylory. (4 marks)

Urea breath test: uses urea C13/14, if positive the isotopes give high reading in CO2 emitted in breath

Biopsy urease test: biopsy tissue is placed in urea solution containing pH indicator, positive within 2 min to 2 hrs

8. List FIVE (5) important characteristics of Actinomycetes israelii (5 marks)

slow growing

diptheroid-like bacilli

colonies form fungus-like branching (hyphae)

gram positive

some aerobic some anaerobic

non sporing

9. List TWO (2) exotoxin produced by Bacillus anthracis (2 marks)

lethal toxin

edema toxin

10. Define malignant pustule. (4 marks)

a form of anthrax causing sevre skin ulceration

11. List TWO (2) diseases caused by C. trachomatis (4 marks)

Lymphogranuloma venereum

Genital tract infection

Inclusion conjunctivitis

PART C : ESSAY QUESTIONS (30 Marks)

Answer THREE (3) questions out of FOUR (4) Questions.

QUESTION 1

A 25-year –old-woman has a popular rash on her trunk, arms and palms. She says the rash does not itch. Vaginal exam reveals two flat, moist, slightly raised lesion examined in a dark field microscope.

a. What is the final diagnosis (name of the disease) of this patient? (1 mark)

Syphilis

b. What is the MOST likely organism that cause the disease (1 mark)

Treponema pallidum

c. Describe on laboratory test to confirm your diagnosis (8 marks)

Dark field microscopy

Direct fluorescent antibody test detects antigen

Venereal Disease Research Lab checks blood or spinal fluid for antibody

Rapid Plasma Reagin finds antibody

Fluorescent treponemal antibody absorption checks for antibody in first 3 to 4 weeks

Treponema pallidum immobilisation/haemagglutination

QUESTION 2

a. Classify human pathogen’s spirochetes. (1 marks)

Trepenoma

Leptospira

Borrelia

b. Describe briefly non-specific and specific serological tests used for the diagnosis of syphilis. (9 marks)

Wasserman complement fixation

Kahn flocculation

Venereal Disease Research Lab checks blood or spinal fluid for antibody

Rapid Plasma Reagin finds antibody

Fluorescent treponemal antibody absorption checks for antibody in first 3 to 4 weeks

Treponema pallidum immobilisation/haemagglutination

QUESTION 3

a. Describe the morphology of Vibrio cholera. (4 marks)

gram negative

curved/rod

non sporing

non capsulated

unipolar flagellum

b. Describe cultural characteristic of Vibrio cholera on nutrient agar, TCBS, and MacConkey agar. (6 marks)

Nutrient: moist, round disc colonies

TCBS: yellow colonies, ferments sucrose

MacConkey: colorless then pink colonies

QUESTION 4

A 1-week-old neonate has yellowish exudates in the corners of both eyes. The child is otherwise well, afebrile and feeding normally. Gram stain of exudate reveals no Gram-negative diplococci. A Giemsa-stain smear of the exudate reveals a large cytoplasmic inclusion.

a. What is the most likely organism causing this infection? (1 marks)

Chalmydia

b. What laboratory test would you perform to confirm the identification of the causative organism? Give the expected results for that test. (8 marks)

Specimen: urine, swab

Direct microscopy: immunofluorescent/electron, demonstartion of inclusion

Direct fluorescent antibody

Nucleic acid amplification test: DNA-RNA hybirdization (genital)

Giemsa stain

Cytology

PCR

Serology: detect IgM antibodies against Chlamydia

c. What is the final diagnosis (name of the disease) of this patient? (1 marks)

Inclusion conjunctivitis

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