Prevalence of beta-lactamases among 1,072 clinical strains of Proteus mirabilis: a 2-year survey in a French hospital

Antimicrob Agents Chemother. 2000 Jul;44(7):1930-5. doi: 10.1128/AAC.44.7.1930-1935.2000.

Abstract

beta-Lactam resistance was studied in 1,072 consecutive P. mirabilis clinical strains isolated at the Clermont-Ferrand teaching hospital between April 1996 and March 1998. The frequency of amoxicillin resistance was 48.5%. Among the 520 amoxicillin-resistant isolates, three resistance phenotypes were detected: penicillinase (407 strains [78.3%]), extended-spectrum beta-lactamase (74 strains [14. 2%]), and inhibitor resistance (39 strains [7.5%]). The penicillinase phenotype isolates were divided into three groups according to the level of resistance to beta-lactams, which was shown to be related to the strength of the promoter. The characterization of the different beta-lactamases showed that amoxicillin resistance in P. mirabilis was almost always (97%) associated with TEM or TEM-derived beta-lactamases, most of which evolved via TEM-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amoxicillin / pharmacology
  • France
  • Gene Frequency
  • Hospitals, Teaching
  • Humans
  • Microbial Sensitivity Tests
  • Penicillin Resistance / genetics
  • Penicillinase / metabolism
  • Penicillins / pharmacology
  • Phenotype
  • Proteus mirabilis / drug effects
  • Proteus mirabilis / enzymology*
  • Proteus mirabilis / genetics
  • beta-Lactam Resistance
  • beta-Lactamase Inhibitors
  • beta-Lactamases / analysis*
  • beta-Lactamases / genetics

Substances

  • Penicillins
  • beta-Lactamase Inhibitors
  • Amoxicillin
  • Penicillinase
  • beta-Lactamases