Diversity of chromosomal AmpC beta-lactamases from Enterobacter cloacae isolates in a Portuguese hospital

FEMS Microbiol Lett. 2004 Jan 30;230(2):197-202. doi: 10.1016/S0378-1097(03)00891-7.

Abstract

Six clinical isolates of Enterobacter cloacae isolated in a Portuguese hospital, between April 1999 and November 2000, demonstrated resistance to almost all broad-spectrum cephalosporins, except to cefepime. These isolates were susceptible to quinolones and to aminoglycosides. Isoelectric focusing demonstrated production of beta-lactamases with pIs > 8.0 and by all six isolates, exhibiting a cephalosporinase phenotype. The results of pulsed field gel electrophoresis revealed that these isolates were genetically unrelated. The amino acid sequence of six AmpC beta-lactamases (Eclo1FF, Eclo6FF, Eclo9FF, Eclo10FF, Eclo11FF and Eclo15FF) shared 97-99% homology with the chromosomal AmpC beta-lactamase from E. cloacae P99 and 86-87% homology with those of two plasmid-mediated AmpC beta-lactamases, MIR-1 and ACT-1. This is the first report of chromosomal AmpC beta-lactamase production by E. cloacae isolates in a Portuguese hospital.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins*
  • Cephalosporin Resistance
  • Chromosomes, Bacterial*
  • Enterobacter cloacae / drug effects
  • Enterobacter cloacae / enzymology*
  • Enterobacter cloacae / genetics
  • Enterobacteriaceae Infections / epidemiology*
  • Enterobacteriaceae Infections / microbiology
  • Genetic Variation*
  • Genotype
  • Hospitals, Urban*
  • Humans
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Phylogeny
  • Polymerase Chain Reaction
  • Portugal / epidemiology
  • Prevalence
  • Transformation, Bacterial
  • beta-Lactamases / genetics
  • beta-Lactamases / metabolism*
  • beta-Lactams / pharmacology

Substances

  • Bacterial Proteins
  • beta-Lactams
  • AmpC beta-lactamases
  • beta-Lactamases