title: Prevalence and types of extended-spectrum beta-lactamases among urinary Escherichia coli and Klebsiella spp. in New Zealand.
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.
authors.affiliation: Antibiotic Reference Laboratory, Institute of Environmental Science and Research (ESR), Wellington, New Zealand. helen.heffernan@esr.cri.nz
authors.forename: Helen M
authors.initials: HM
authors.lastname: Heffernan
authors.forename: Rosemary E
authors.initials: RE
authors.lastname: Woodhouse
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Pope
authors.forename: Timothy K
authors.initials: TK
authors.lastname: Blackmore
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D017714:Community-Acquired Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D005838:Genotype; D006801:Humans; D007711:Klebsiella pneumoniae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D014552:Urinary Tract Infections / Q000382:microbiology*; D055815:Young Adult; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000145:classification*
chemical_list: D004269:DNA, Bacterial; D001618:beta-Lactamases