Microbiology Theory Paper

  1. The following are characteristics of Staphylococcus aureus except:

a) Grows on ordinary culture media

b) It’s non-motile

c) It’s non-capsulated

d) It’s a gram-negative cocci


2. McFadyean’s reaction is employed for the presumptive diagnosis of:

a) Typhoid

b) Diptheria

c) Anthrax

d) Tetanus


3. A stormy clot reaction is useful in the identification of:

a) Clostridium perfringens

b) Clostridium difficile

c) Clostridium botulinum

d) Clostridium tetani


4. In bacillary dysentery, Shigella may be isolated from

a) Urine

b) CSF

c) Stool

d) Blood


5. Which of the following properties is not seen in the members of the family Enterobacteriaceae?

a) The reduce nitrates to nitrites

b) They ferment glucose

c) They are oxidase-positive

d) The are catalase negative


6. Which of the following bacteria is a lactose fermenter?

a) Shigella dysentery

b) Shigella sonnei

b) Salmonella typhi

d) Salmonella paratyphi A



7. The ability of some bacteria to retain crystal violet-iodine  complex in the Gram stain depends on:

a) Shape of the cell

b) Amount of outer membrane proteins present

c) Presence of a capsule

d) Amount of peptidoglycan


8. Streptococcus pyogenes can be differentiated from other hemolytic streptococci on the basis of sensitivity to:

a) Bacitracin

b) Optochin

c) Penicillis

d) Erythromycin


9. Ascoli’s thermoprecipitin test is a confirmatory test for:

a) Diptheria

b) Anthrax

c) Meningitis

d) Typhoid


10. texponential phase of the growth curve of bacteria is of limited duration because of:

a) Rise in pH

b) Rise in the cell membrane

c) Presence of nutrients

d) Accumulation of toxic metabolites


11. Moist heat is used for sterilization of:

a) Gloves

b) Glucose solution

c) Serum

d) Chemical powder


12. Inhibition of microorganisms in living tissues is known as:

a) Disinfection

b) Antisepsis

c) Sterilization

d) Sanitation


13. Koch’s postulates were identified for the first time with:

a) Bacillus anthracis

b) Heamophilus ducreyi

c) Haemophilus influenza

d) Bacillus subtilis


14. An elderly hospitalized patient has developed lobar pneumonia.  Which of the following organisms could be suspected?

a) Haemophillus influenza

b) Klebsiella pneumonia

c) Enterobacter aeogenes

d) Staphylococcus aureus


15. The process of rendering an article free from living organisms including bacterial, fungal spores, and viruses is known as:

a) Infection

b) Sepsis

c) Sterilization

c) Sanitation


16. Antibiotics act through the following ways EXCEPT:

a) Inhibit cell wall synthesis

b) Enhance plasmid replication

c) Inhibit DNA function

d) Inhibit cell membrane synthesis


17. Which of the following organisms is an opportunistic pathogen isolated from the urinary tract and wound infection in human beings?

a) Klebsiella pneumonia

b) Proteus Vulgaris

c) Streptococcus agalactiae

d) Salmonella enteritidis


18. Which of the following bacterial genus can be isolated in an acidic environment?

a) Vibrio

b) Salmonella

c) Lactobacillus

d) Shigella


20. Which of the following media serves as an enrichment medium for Salmonella?

a) Selenite F

b) Alkaline peptone water

c) Salmonella Shigella agar

d) Liver infusion broth


21. Which of the following organisms grow at a pH of 8.6?

a) Pseudomonas aeroginosa

b) Vibrio cholera

c) Bascillus anthracis

d) Mycobacterium avium