In vivo reversion to the wild-type beta-lactam resistance phenotype mediated by a plasmid carrying ampR and qnrA1 in Enterobacter cloacae

Antimicrob Agents Chemother. 2006 Sep;50(9):3175-8. doi: 10.1128/AAC.00273-06.

Abstract

Resistance to beta-lactams and quinolones in two isogenic Enterobacter cloacae isolates was studied. One was susceptible to cefoxitin and amoxicillin-clavulanate. The other one showed its natural beta-lactam resistance pattern. Both isolates had a nonfunctional AmpR regulator. However, within the second one, the presence of a plasmid carrying ampR and qnrA1 allowed reversion to the wild-type beta-lactam resistance phenotype and decreased susceptibility to fluoroquinolones.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amoxicillin-Potassium Clavulanate Combination / pharmacology
  • Bacterial Proteins / genetics*
  • Cefoxitin / pharmacology
  • Enterobacter cloacae / drug effects
  • Enterobacter cloacae / genetics*
  • Enterobacter cloacae / isolation & purification
  • Enterobacteriaceae Infections / microbiology
  • Humans
  • Microbial Sensitivity Tests
  • Plasmids / genetics
  • Polymerase Chain Reaction
  • Quinolones / pharmacology
  • beta-Lactam Resistance / genetics*

Substances

  • Bacterial Proteins
  • Quinolones
  • AmpR protein, Bacteria
  • Cefoxitin
  • Amoxicillin-Potassium Clavulanate Combination