Medical Dictionary


noun be·ta–lac·ta·mase
variants: also


\-ˈlak-tə-ˌmās, -ˌmāz\play

Medical Definition of beta–lactamase

  1. :  any of various bacterial enzymes that inactivate beta-lactam antibiotics (such as penicillin and cephalosporin) by hydrolyzing them When confronted with an antibiotic, a number of disease-causing bacteria will retaliate by making an enzyme called beta-lactamase …—Diana Morgan and Terence Monmaney, Science, July/August 1985 The most common mechanism of resistance to β-lactam antibiotics is the bacterial production of an enzyme called β-lactamase, which breaks one of the antibiotic's chemical bonds, changing its structure and preventing it from inhibiting the enzyme transpeptidase.—K. C. Nicolaou et al., Scientific American, May 2001 Beta-lactamase was originally used only to refer to bacterial enzymes that inactivated penicillin. As additional types of beta-lactam antibiotics were introduced, other bacterial beta-lactamases were identified. —compare penicillinase

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a brief usually trivial fact

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