resistance to beta-lactam antibiotics can be related to many beta-lactamase-mediated phenomena , including increased frequency of beta-lactamase production in clinical isolates , wider distribution of beta-lactamase-mediating plasmids , production of multiple beta-lactamases , induction of chromosomal class 1 cephalosporinases , selection of depressed mutants for production of class 1 enzymes , leakage of beta-lactamase from gram-negative organisms , functions of penicillin-binding proteins as beta-lactamases , and identification of novel beta-lactamases .
C0728805
cephalosporinases
C0597979
beta-lactamases