7 - microbiology basics (mcqs)

1. Name some Gram positive cocci.
- Staphylococcus spp, Streptococcus spp, Micrococcus spp and Enterococcus spp.

2. Name some Gram positive bacilli.
- Clostridium spp, Corynebacterium diphtheriae, Bacillus spp, Listeria sp and Lactobacillus sp.

3. Name some Gram negative bacilli.
- Escherichia coli, Shigella sp, Klebsiella sp, Pseudomonas sp, Vibrio sp and Haemophilus sp.

4. Name some aerobes.
- Mycobacterium tuberculosis, Pseudomonas sp, Micrococcus sp and Acinetobacter sp.

5. Name some obligate anaerobes.
- Clostridium sp, Bacteroides sp and Prevotella sp.

6. Name some facultative anaerobes.
- Staphylococcus aureus and members of Enterobacteriaceae.

7. Name some microaerophilic bacteria.
- Campylobacter sp and Helicobacter sp.

8. Name the capnophilic bacteria.
- Brucella abortus (5 -10% CO2), Pneumococcus, Haemophilus sp and Neisseria sp.

9. Name some motile bacilli.
- Escherichia coli, Vibrio cholerae, Salmonella sp and Proteus sp.

10. Name some non-motile bacilli.
- Klebsiella spp and Shigella spp.

11. Name some capsulated bacteria.
- Klebsiella sp, Pneumococcus, Neisseria meningitidis, Bacillus anthracis, Haemophilus influenzae type b and Vibrio parahaemolyticus.

12. What are the different arrangements of flagella?
- Monotrichous, Lophotrichous, Amphitrichous and Peritrichous.

13. Name some spore bearing bacteria.
- Bacillus spp (aerobic) and Clostridium spp (anaerobic).

14. Name some pigment-producing bacteria.
- Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcens, Chromobacterium violaceum, Prevotella melaninogenica, photochromogens and scotochromogens of Mycobacterium.

15. What is bacterial cell wall made up of?
- Peptidoglycan (mucopeptide).

16. Name bacteria that cannot be stained by Gram’s stain.
- Mycobacterium sp, Chlamydiae, Rickettsiae, Treponema sp, Leptospira sp and Calymmatobacterium granulomatis.

17. Name some bacteria that can not be cultured on artificial culture medium.
- Mycobacterium leprae, Chlamydiae, Rickettsiae, Calymmatobacterium granulomatis and Treponema sp.

18. Name some β–haemolytic bacteria.
- Staphylococcus aureus, Group A & B Streptococcus and Listeria sp.

19. Name some α–haemolytic bacteria.
- Pneumococcus, Viridans Streptococci and some species of Enterococcus.

20. What are “coliforms” and “paracolons”?
- Escherichia coli and Klebsiella sp, which inhabit the intestine are called coliforms. Paracolon is an old term, earlier referred to non-lactose fermenting enteric bacteria other than Salmonella sp, Shigella sp and Proteus sp. They include Enterobacter sp, Citrobacter sp, Hafnia sp etc.

21. What is the normal flora of intestine?
- Bacteroides sp, Escherichia coli, Clostridium sp etc.

22. What is the normal flora of skin?
- Staphylococcus epidermidis, Diphtheroids and Propionibacterium sp.

23. Name some fastidious bacteria.
- Haemophilus sp, Streprococcus sp, Brucella sp, Bordetella sp and Mycobacterium sp.

24. What are Protoplasts, spheroplasts and L-forms?
- Gram positive bacteria without cell wall forms protoplast while gram negative bacteria forms spheroplast. When such forms are able to multiply they are termed L-forms.

25. Name the bacteria that totally lack cell wall.
- Mycoplasma sp and Ureaplasma sp.

26. What is the significance of L–forms?
- They may remain latent in the body, are refractive to antibiotics against cell wall synthesis and causes relapse of infection.

27. How do bacteria multiply?
- Binary fission.

28. What is the nature of bacterial capsule?
- Usually the capsule is made up of polysaccharide, but in Bacillus anthracis the capsule is made up of ployglutamic acid (protein).