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beta-lactam antibioticsAn important group of drugs that includes the penicillins and the cephalosporins. All have a 4-membered beta-lactam ring as part of the basic structure. Many organisms produce beta-lactamase enzymes that can destroy these antibiotics. This is a common cause of bacterial resistance to antibiotics. Certain molecules called BETA-LACTAM INHIBITORS, however, can bind to beta-lactamase enzymes and inactivate them.
a cyclic amide formed from aminocarboxylic acids by elimination of water; lactams are isomeric with lactims, which are enol forms of lactams.
includes the penicillins, cephalosporins, carbapenems and penems. See also β-lactam ring (below).
an integral part of the formula of β-lactam antibiotics. Disruption of the ring by β-lactamase produced by some bacteria, e.g. Escherichia coli, Bacillus anthracis, destroys the antimicrobial activity of the compound.