<prompt> Methicillin-resistant staphylococci do not respond to βlactam antibiotics because :They produce a βlactamase which destroys methicillin and related drugsThey elaborate an amidase which destroys methicillin and related drugsThey have acquired penicillin binding protein which has low affinity for β-lactam antibioticsThey are less permeable to β-lactam antibiotics  <response>: 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. 