Type I beta-lactamases of gram-negative bacteria: interactions with beta-lactam antibiotics

J Infect Dis. 1986 Nov;154(5):792-800. doi: 10.1093/infdis/154.5.792.


The interaction of type I beta-lactamases with diverse beta-lactam compounds representing cephalosporins, cephamycins, penicillins, penams, penems, carbapenems, monobactams, and clavams was examined by using various Enterobacteriaceae and Pseudomonas aeruginosa as sources of the enzymes. The ability of a given drug to reversibly induce beta-lactamase was unrelated to its ability to select mutants stably derepressed for beta-lactamase production. Imipenem was one of the most-potent enzyme inducers, yet it did not select derepressed mutants. Many of the newer cephalosporins were poor enzyme inducers but readily selected derepressed mutants. Resistance to hydrolysis did not predict a drug's inhibitory activity against derepressed mutants. The activity of the penems, penams, and carbapenems was least affected by derepression of beta-lactamase, whereas the activity of anionic cephalosporins and aztreonam was most affected.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / metabolism*
  • Gram-Negative Bacteria / enzymology*
  • Hydrolysis
  • Microbial Sensitivity Tests
  • Mutation
  • beta-Lactamases / metabolism*
  • beta-Lactams


  • Anti-Bacterial Agents
  • beta-Lactams
  • beta-Lactamases