Question

Oxacillin resistance of MRSA is due to production of which of the following penicillin binding proteins (PBPs)?

a) PBP2
b) PB2a
c) PBP3
d) PBP4

Answer 1

Oxacillin resistance in MRSA is due to the production of PBP2a, a penicillin-binding protein. PBP2a prevents ß-lactam antibiotics from effectively targeting MRSA, resulting in resistance to these antibiotics.

Step-by-step explanation:

The oxacillin resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) is due to the production of PBP2a, a penicillin-binding protein with low affinity for ß-lactam antibiotics. This new penicillin-binding protein is acquired through gene acquisition, meaning MRSA essentially becomes resistant to all ß-lactam drugs except for the newer fifth-generation cephalosporins. In the presence of this resistance mechanism, traditional antibiotics like oxacillin are ineffective against MRSA, which necessitates alternative treatments like vancomycin.