Nosocomial bacteremia and urinary tract infections caused by extended-spectrum beta -lactamase-producing Klebsiella pneumoniae with plasmids carrying both SHV-5 and TLA-1 genes

Clin Infect Dis. 2004 Apr 15;38(8):1067-74. doi: 10.1086/382354. Epub 2004 Mar 24.

Abstract

We describe the prevalence and molecular characteristics of extended-spectrum beta -lactamase (ESBL)-producing Klebsiella pneumoniae causing nosocomial bacteremia and urinary tract infections in a Mexican general hospital. We analyzed 82 episodes of bacteremia (approximately 60% of episodes) and urinary tract infection (approximately 40% of episodes) due to K. pneumoniae during a 23-month surveillance period. The neonatal intensive care unit accounted for 49% of all episodes. All strains were imipenem susceptible; 62.2% of the strains were resistant to ceftazidime, cefotaxime, and aztreonam; 69.5% were resistant to amikacin; 58.5% were resistant to gentamicin; and 7.3% were resistant to ciprofloxacin. All strains were associated with 28 pulsed-field gel electrophoresis patterns, and dissemination of 2 ceftazidime-resistant clones produced 44% of the cases. The ESBL phenotype in these clones was transferred by identical or highly related megaplasmids. The ESBL activity corresponded to SHV-5 and TLA-1. Cross-transmission of 2 ceftazidime-resistant clones and the horizontal spread of identical or highly related megaplasmids explain the high prevalence of ESBL phenotype in these infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteremia / microbiology
  • Cross Infection / microbiology*
  • Drug Resistance, Bacterial
  • Genotype
  • Hospitals
  • Humans
  • Klebsiella Infections / microbiology
  • Klebsiella pneumoniae / drug effects*
  • Microbial Sensitivity Tests
  • Plasmids / genetics
  • Urinary Tract Infections / microbiology*
  • beta-Lactam Resistance*
  • beta-Lactamases / genetics*

Substances

  • beta-Lactamases