Question

Which of the following modes of action would not be fungicidal?

a. inhibition of peptidoglycan synthesis

b. inhibition of mitosis

c. injury to the plasma membrane

d. inhibition of nucleic acid synthesis

e. All of the above are fungicidal modes of action

Answer 1

Correct option is A: inhibition of peptidoglycan synthesis is not fungicidal

During normal bacterial growth, bacterial enzymes called autolysins put breaks in the peptidoglycan in order to allow for insertion of peptidoglycan building blocks (monomers of NAG-NAM-peptide). These monomers are then attached to the growing end of the bacterial cell wall with transglycosidase enzymes. Finally, transpeptidase enzymes join the peptide of one monomer with that of another in order to provide strength to the cell wall. Penicillins and cephalosporins bind to the transpeptidase enzyme and block the formation of the peptide cross-links. This results in a weak cell wall and osmotic lysis of the bacterium.

All the other options are fungicidal