Question

Which of following are NOT killed by pasteurization: a. Campylobacter jejuni b. Mycobacterium bovis & tuberculosis c. Staphylococcus aureus d. Brucella abortis

Which of the following is FALSE regarding Gluteraldehyde?

	a.	It is effective in presence of organic material
	b.	It has residual activity
	c.	It is virucidal but NOT sporicidal
	d.	It is toxic to humans
	e.	It is fungicidal and parasiticidal

Which of the following is NOT a direct mode of action of antimicrobial drugs?

	a.	inhibition of bacterial cell wall synthesis
	b.	inhibition of host folic acid synthesis
	c.	inhibition of bacterial protein synthesis
	d.	inhibition of bacterial nucleic acid synthesis

Answer 1

3. Answer: (b) inhibition of host folic acid synthesis

Explanation:

Antibiotic drugs are generally to two types bactericidal and bacterostatic. The bactericidal antibiotics kills the bacteria but the bacteriostatic antibiotic did not kill the bacteria but prevent or inhibit their growth.

In this case inhibiting bacterial cell wall synthesis, inhibiting bacterial protein synthesis and inhibition of bacterial nucleic acid synthesis are the direct mode of action which directly kills the bacteria.

But the inhibition of host (can be human or animals infected by the bacteria) folic acid synthesis, the bacteria may not be able to survive and grow inside the host. This is indirect mode of action which does not act directly on the bacteria.