The revolving door between hospital and community: extended-spectrum beta-lactamase-producing Escherichia coli in Dublin.
BACKGROUND
Escherichia coli that produce extended-spectrum beta-lactamases (ESBLs) are an increasing cause of healthcare-associated infection, and community healthcare facilities may be a reservoir for important epidemic clones.


OBJECTIVE
To characterize retrospectively and investigate the epidemiology of ESBL-producing E. coli collected in a Dublin hospital, during 2009 and 2010, and to investigate the dissemination of specific clones within hospital and community healthcare facilities.


METHODS
Pulsed-field gel electrophoresis (PFGE) was used to determine the genetic relatedness of 100 ESBL-producing E. coli isolates. Phylogenetic groups were determined and the O25b-ST131 clone identified in the collection. The genetic data were correlated with antimicrobial susceptibility, clinical and demographic data to explore the epidemiology of specific clones.


RESULTS
Phylogenetic groups B2 (62%) and D (18%) were the most common and were associated with non-urinary isolates (P<0.0001 by Fisher's exact test). PFGE revealed 12 clusters (≥ 80% similarity), the largest of which clustered with the epidemic UK strain A. Residents of long-term care facilities (LTCFs) in the community exclusively carried the O25b-ST131 clone and phylogenetic groups B2 and D.


CONCLUSIONS
E. coli O25b-ST131 is largely responsible for ESBL-producing E. coli in LTCFs in Dublin. The distribution of ESBL-producing E. coli in our hospital and community highlights a 'revolving door' through which these resistant bacteria spread and disseminate.
Department of Clinical Microbiology, Royal College of Surgeons in Ireland Education and Research Centre, Beaumont Hospital, Dublin, Ireland. liamburke@rcsi.ie
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Burke
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Humphreys
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Fitzgerald-Hughes
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010802:Phylogeny; D055815:Young Adult; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases