Bacteriology Sample Exam

Institute of Clinical Laboratory Sciences SILLIMAN UNIVERSITY Rotational Examination Microbiology Set A Name: ________________________

Score: ___________

Institution: _____________________

Date: ____________

INSTRUCTIONS: Choose the letter of the correct answer from the choices provided under each question. Write your answers on the space before each item. Superimpositions are strictly not allowed.

___1. Bacteria characterized by the presence of Teichoic Acid and a think Peptidoglycan layer in the cell wall. a)

Gram Negative Bacteria

c)

Gram Positive Bacteria

b)

Fungi

d)

Archeobacteria

e)

___2. An unusual component in the cell wall of Mycobacteria that results in its inability to be gram stained.

a)

Teichoic Acid

c)

Porins

b)

Mycolic Acid

d)

Murein

e)

___3. What reagent in gram staining differentiates gram positive and gram negative bacteria, and is considered to be the most important reagent in gram staining.

a)

Crystal Violet

c)

Ethanol

b)

Gram’s Iodine

d)

Safranin

f) a) b) e) a) b) e) a) b) e) a) b) e) a) b) e)

___4. This is the stage in the bacterial life cycle in which metabolic activities occur but the organisms do not divide. Lag phase c) Stationary phase Log phase d) Death phase ___5. All are common normal flora found in the urinary tract of females except: S. agalactiae c) E. coli G. vaginalis d) AOTA ___6. Which of the ff. organisms is NOT found in the respiratory tract of humans? Neisseria spp. c) Enterobacter spp. Streptococcus spp. d) Staphylococcus spp. ___7. Which of the ff agar plates would NOT be used in the culture of a urine specimen? Blood Agar c) Salmonella-Shigella Agar MacConkey Agar d) Both A and B ___8. What is the total magnification of the microscope when using the HPO? 400 c) 40 100 d) 1000 ___9. What is the true bacterial count/ml if a total 100 organisms were counted on an agar plate inoculated with 0.1ml from a 1:10,000 dilution? 100,000/ml d) No count should be made because the sample was diluted 1,000,000/ml making it invalid 10,000,000/ml ___10. It is the complete destruction of all microorganisms including spores. Sterilization c) AOTA Disinfection d) NOTA ___11. At what temperature can an autoclave kill all organisms? 100 degrees Celsius at 15 PSI c) 135 degrees Celsius at 10 PSI 121 degrees Celsius at 15 PSI d) 125 degrees Celsius at 15 PSI

a) b) c) f) a) b) e) a) b)

f) a) b) e) a) b) f) a) b) e) a) b) e) a) b) e) a) b) e) a) b) f) a) b) e) a) b) f) g) h) a) b) e) a) b) e) a) b) f) a) b) e) a) b) f) a) b) e) a) b) c) d)

___12. True antibiotics are substances that can kill or inhibit the growth of susceptible organisms and are produced by: Bacteria c) Laboratories Fungi d) Both A and B ___13. In Ziehl Neilsen acid fast staining, what acts as the mordant? Heat c) Iodine Acid alcohol d) Tergitol ___14. Ziehl Neilsen acid fast staining, what do acid fast bacilli look like? Blue against a red background c) Blue against a blue background Red against a blue background d) Many different colors depending on the type of bacteria ___15. This biosafety cabinet is closed and air enters and exits through HEPA filters. Class I c) Class II A Class II B d) Class III ___16. What is the most specific test for the identification of S. aureus? Catalase test c) Bound coagulase Culture on MSA d) Free coagulase ___17. Which test differentiates Staphylococcus from Streptococcus? Catalase test c) Blood agar growth Culture on MSA d) NOTA ___18. What is the characteristic colony color S. aureus on MSA? Yellow c) White Blue d) Red ___19. This test is used to differentiate group D strep from other groups. Bile esculin c) Hemolytic Pattern CAMP d) Acetamide test ___20. This test is used to differentiate Enteric group D from Non-enteric group D strep. 6.5% NaCl tolerance c) Bile Esculin Catalase test d) PYR test ___21. Differentiates S. pyogenes from S. agalactiae Beta hemolysis on BAP c) Bile hydrolysis Bacitracin Susceptibility d) Coagulase + ___22. The only sugar N. gonorrheae is able to ferment. Maltose c) Lactose Glucose d) Sucrose ___23. Which of the ff. enterobacteriaceae generally does not ferment lactose? Escherichia spp. c) Salmonella spp. Klebsiella spp. d) Enterobacter spp ___24. Which of the ff. enterobacteriaceae generally does not produce H 2S in TSI? Salmonella spp. c) E. coli Proteus spp. d) Edwardsiella spp. ___25. What is the positive reaction of the indole test? Blue color development after addition of Erlich’s rgt. c) Yellow color development after addition of Erlich’s rgt. Pink color development after addition of Erlich’s rgt. d) Green color development after addition of Erlich’s rgt. ___26. What is the positive reaction of the citric acid utilization test? Blue color of the slant c) AOTA Growth on slant d) NOTA ___27. What is the positive reaction of the Urease test? No color change Purple color change Yellow color change Blue color change

f) a) b) e) a) b) f) a) b) e)

___28. In the CAMP test, what is the organism that is inoculated to enhance hemolysis? S. epidermidis c) S. sanguis S.aureus d) S. campinii ___29. What bacteria produces the V factor? S. epidermidis c) S. sanguis S.aureus d) S. campinii ___30. This bacteria is commonly transmitted sexually in young females. Trichomonas vaginalis c) Neisseria meningitides E. coli d) S. saprophyticus ___31. What species of Mycobacterium causes Leprosy?

e) f) 41-48. Enumerate the four IMViC Tests and their positive reactions. g) h) i) j) k) l) m) n) o) 49-50. Give two tests used in the work-up of beta-hemolytic strep. p) q) r)

s)