sentences:  Another more efficient form of resistance to cefoxitin is provided by the mecA gene in bacteria.This gene codes for an alternative penicillin binding protein, PBP2a.This PBP has a lower binding affinity for penicillin-based antibiotics such as cefoxitin and will continue to cross-link the peptidoglycan layers of the cell wall even in the presence of the beta-lactam antibiotics.