Prevalence and types of extended-spectrum beta-lactamases among urinary Escherichia coli and Klebsiella spp. in New Zealand

Int J Antimicrob Agents. 2009 Dec;34(6):544-9. doi: 10.1016/j.ijantimicag.2009.07.014. Epub 2009 Sep 11.

Abstract

The aims of this survey were (i) to determine the prevalence of extended-spectrum beta-lactamases (ESBLs) among urinary Escherichia coli and Klebsiella spp. in New Zealand (NZ), (ii) to identify the relative prevalence of ESBL types and (iii) to investigate clonality among ESBL-producing E. coli and Klebsiella spp. During a 4-week period in 2006, 86% of NZ hospital and community diagnostic microbiology laboratories participated in the survey and referred isolates to the national reference laboratory. A total of 86 ESBL-producing isolates were identified, comprising 55 E. coli and 31 Klebsiella spp. (all Klebsiella pneumoniae), equating to prevalence rates of 0.7% and 4.2%, respectively. The majority of the ESBL-producing E. coli (80.0%) and K. pneumoniae (58.6%) were reported to be from community-acquired urinary tract infections. CTX-M-15 and CTX-M-14 accounted for 75.9% and 13.3%, respectively, of the ESBL types identified. A novel ESBL, designated CTX-M-68, was identified. Most CTX-M-15-producing isolates were multiresistant to three or more antibiotic classes. Pulsed-field gel electrophoresis typing identified a wide diversity of strains among the ESBL-producing E. coli, whereas the K. pneumoniae were more clonal. The results of this survey show that the prevalence of ESBLs has increased in recent years in NZ, that CTX-M ESBLs are almost wholly dominant and that ESBL-producing organisms are already established as community-acquired pathogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Bacterial Typing Techniques
  • Child
  • Child, Preschool
  • Cluster Analysis
  • Community-Acquired Infections / microbiology
  • Cross Infection / microbiology
  • DNA Fingerprinting
  • DNA, Bacterial / genetics
  • Electrophoresis, Gel, Pulsed-Field
  • Escherichia coli / classification
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli / isolation & purification
  • Female
  • Genotype
  • Humans
  • Klebsiella pneumoniae / classification
  • Klebsiella pneumoniae / enzymology*
  • Klebsiella pneumoniae / genetics
  • Klebsiella pneumoniae / isolation & purification
  • Male
  • Middle Aged
  • New Zealand
  • Urinary Tract Infections / microbiology*
  • Young Adult
  • beta-Lactamases / biosynthesis*
  • beta-Lactamases / classification*

Substances

  • DNA, Bacterial
  • beta-Lactamases