FPGEE FPGEE Microbiology and Immunology 3

Question 1

Which of the following best describes herd immunity?

Accepted Answer

A sufficient proportion of a population is immune, reducing pathogen spread to unvaccinated individuals

Answer

All individuals in a population are vaccinated

Answer

Only healthcare workers are vaccinated to protect patients

Answer

Immunity acquired after natural infection only

Question 2

Neisseria gonorrhoeae is resistant to penicillin mainly because of:

Accepted Answer

Altered PBPs and beta-lactamase production

Answer

Efflux pumps only

Answer

Capsule preventing drug entry

Answer

Altered 30S ribosomal subunit

Question 3

The live attenuated varicella (chickenpox) vaccine is a contraindication in pregnancy primarily because:

Accepted Answer

Live vaccine virus may cross the placenta and infect the fetus

Answer

It causes teratogenic malformations via direct drug toxicity

Answer

It reduces maternal antibody transfer

Answer

It induces preterm labor

Question 4

Which innate immune cell is the primary phagocyte responsible for clearing bacterial infections in the bloodstream?

Accepted Answer

Neutrophils

Answer

B lymphocytes

Answer

Natural killer (NK) cells

Answer

Eosinophils

Question 5

Which antiviral agent inhibits the neuraminidase enzyme of influenza A and B viruses?

Accepted Answer

Oseltamivir

Answer

Acyclovir

Answer

Ribavirin

Answer

Ganciclovir

Question 6

The Mantoux tuberculin skin test (TST) detects prior exposure to Mycobacterium tuberculosis by measuring which immune response?

Accepted Answer

Type IV delayed-type hypersensitivity (DTH)

Answer

Type I IgE-mediated hypersensitivity

Answer

Type II antibody-mediated cytotoxicity

Answer

Complement activation