beta (beta)-lactam antibiotics
be·ta (β)-lac·tam an·ti·bi·ot·ics(bā'tă-lak'tam an'tē-bī-ot'iks)
A group of natural and semisynthetic agents that inhibit the final stage of cell wall synthesis by binding with transpeptidases essential in the formation of peptide bonds. These antibiotics have a common chemical structure called the beta-lactam ring. Beta-lactam antibiotics include the penicillins and cephalosporins.