Predominance and genetic diversity of community- and hospital-acquired CTX-M extended-spectrum beta-lactamases in York, UK.
OBJECTIVE
This study was conducted to detect the presence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae within the faecal flora of both community- and hospital-based patients in York and to characterize the bla(TEM), bla(SHV) and bla(CTX-M) genes present in these isolates.


METHODS
One thousand faeces samples were collected and screened at York Hospital during October-December 2003. Ninety-five non-duplicate Enterobacteriaceae isolates resistant to third-generation cephalosporins were recovered; 22 isolates were selected for further study on the basis of a positive double disc diffusion test for ESBL production. Antibiotic susceptibility testing was performed to a range of antibiotics. The TEM, SHV and CTX-M genes were detected by PCR and the DNA sequenced.


RESULTS
The distribution of ESBL-positive isolates from the hospital and community was 1.4:1. These included nine Escherichia coli, seven Enterobacter cloacae, four Citrobacter freundii and a single isolate each of Klebsiella spp. and Salmonella spp. A total of 17 isolates contained bla(CTX-M) (five bla(CTX-M-15), three bla(CTX-M-14) and nine bla(CTX-M-9)). ISEcp1 was present in isolates expressing CTX-M-14 and -15, but was absent upstream of In60-associated bla(CTX-M-9). E. coli isolates also contained either a bla(TEM-1) or bla(TEM-2), whereas six of the E. cloacae carried bla(SHV-12) and the Klebsiella spp. bla(SHV-36) in addition to bla(CTX-M-9). The single Salmonella spp. carried bla(SHV-12).


CONCLUSIONS
The overall prevalence of ESBL in isolates of Enterobacteriaceae from York was 1.9%. ESBL-producing isolates were found in both the community and hospital, with the CTX-M type most common. This is also the first report of an ESBL-producing Salmonella in the UK.
Antimicrobial Agents Research Group, Division of Immunobiology and Infection, The Medical School, University of Birmingham, Vincent Drive, Edgbaston, Birmingham, UK.
C J
CJ
Munday
G M
GM
Whitehead
N J
NJ
Todd
M
M
Campbell
P M
PM
Hawkey
D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology*; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology*; D014644:Genetic Variation; D006801:Humans; D008826:Microbial Sensitivity Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D006113:United Kingdom / Q000453:epidemiology; D001618:beta-Lactamases / Q000378:metabolism*
D004269:DNA, Bacterial; D001618:beta-Lactamases