Extended-spectrum beta-lactamase in Proteus mirabilis

J Antimicrob Chemother. 1994 May;33(5):925-35. doi: 10.1093/jac/33.5.925.

Abstract

Over a period of one month, five isolates of Proteus mirabilis resistant to extended-spectrum cephalosporins colonized or infected five patients of the same intensive care unit. The antibiotic resistance phenotype and the metabolic profiles of the five strains were identical. All five produced a plasmid-mediated extended-spectrum beta-lactamase closely related to TEM-3/CTX-1 according to its pI (6.3), to its substrate profile and to the hybridization of the corresponding gene with blaTEM-3 specific oligonucleotide probes. Ability to produce this enzyme transferred by conjugation to Escherichia coli along with aminoglycoside and sulphonamide resistance. These resistance markers were encoded by a plasmid, (pAP1) which was identical in all five isolates but which was different from the TEM-3 beta-lactamase plasmids found in other Enterobacteriaceae. Plasmid pAP1 differed by its smaller size (47 kb), its EcoRI restriction pattern, its resistance co-markers (AAC(6') and sulphonamide only) and its much lower transfer frequency (2 x 10(-8)). Furthermore this plasmid did not belong to any known Enterobacteriaceae incompatibility group.

MeSH terms

  • Cephalosporinase / metabolism*
  • Cephalosporins / pharmacology
  • Cross Infection / microbiology
  • DNA, Bacterial / isolation & purification
  • Drug Resistance, Microbial
  • Electrophoresis, Polyacrylamide Gel
  • Escherichia coli / genetics
  • Genetic Markers
  • Humans
  • Intensive Care Units
  • Microbial Sensitivity Tests
  • Nucleic Acid Hybridization
  • Pancreatitis-Associated Proteins
  • Plasmids
  • Proteus Infections / microbiology
  • Proteus mirabilis / drug effects
  • Proteus mirabilis / enzymology*
  • Proteus mirabilis / genetics

Substances

  • Cephalosporins
  • DNA, Bacterial
  • Genetic Markers
  • Pancreatitis-Associated Proteins
  • REG3A protein, human
  • Cephalosporinase