Methicillin-resistant staphylococci do not respond to β–lactam antibiotics because :: (A) They produce a β–lactamase which destroys methicillin and related drugs, (B) They elaborate an amidase which destroys methicillin and related drugs, (C) They have acquired penicillin binding protein which has low affinity for β-lactam antibiotics, (D) They are less permeable to β-lactam antibiotics
Answer is C. Resistance to most penicillins is due to elaboration of beta-lactamase.
Methicillin is most resistant penicillin to β-lactamase.
Staphylococcus aureus develops resistance to methicillin by the acquisition of altered penicillin-binding proteins.