Evolution of plasmid-coded resistance to broad-spectrum cephalosporins

Antimicrob Agents Chemother. 1985 Aug;28(2):302-7. doi: 10.1128/AAC.28.2.302.

Abstract

A clinical isolate of Klebsiella ozaenae with transferable resistance to broad-spectrum cephalosporins produces a beta-lactamase determined by plasmid pBP60. The beta-lactamase had the same isoelectric point as SHV-1 (7.6). From heteroduplex analysis, an extensive homology between the two bla genes could be deduced; therefore, the new beta-lactamase was designated SHV-2. Enzymatic studies revealed that SHV-2 was able to hydrolyze broad-spectrum cephalosporins due to an increased affinity of these compounds for the enzyme. The assumption that SHV-2 is a natural mutant of SHV-1 was strongly supported by the isolation of a laboratory mutant of SHV-1 that showed activities similar to those of SHV-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cephalosporins / metabolism
  • Cephalosporins / pharmacology*
  • Cloning, Molecular
  • DNA, Bacterial / genetics
  • Drug Resistance, Microbial*
  • Genes
  • Genes, Bacterial
  • Klebsiella / drug effects
  • Klebsiella / genetics*
  • Mutation
  • Plasmids
  • Sequence Homology, Nucleic Acid
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism

Substances

  • Cephalosporins
  • DNA, Bacterial
  • beta-Lactamases