Molecular epidemiology and antimicrobial resistance pattern of extended-spectrum-β-lactamase-producing Enterobacteriaceae in Glasgow, Scotland

Khanna, N., Boyes, J., Lansdell, P.M., Hamouda, A. and Amyes, S.G.B. (2012) Molecular epidemiology and antimicrobial resistance pattern of extended-spectrum-β-lactamase-producing Enterobacteriaceae in Glasgow, Scotland. Journal of Antimicrobial Chemotherapy, 67(3), pp. 573-577. (doi: 10.1093/jac/dkr523)

Abstract

<b>Objectives</b> To establish the molecular epidemiology and antimicrobial resistance pattern of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae harbouring blaCTX-M in Glasgow, Scotland.<p></p> <b>Methods</b> During a 12 week period, Enterobacteriaceae isolates obtained from urine samples were collected and susceptibility testing performed. Isolates were screened for the presence of blaCTX-M by multiplex PCR and selected Escherichia coli genes were subsequently sequenced. PFGE analysis was performed on selected E. coli isolates in order to identify clonal relationships.<p></p> <b>Results</b> There were 155 phenotypically confirmed non-duplicate Enterobacteriaceae isolates obtained from urine samples. blaCTX-M was identified in 131/155 (84.5%) of the ESBL-producing isolates, with CTX-M group 1 enzymes accounting for 103/131 (78.6%) of these. The remaining 24 isolates carried other blaCTX-M types, including CTX-M group 2, CTX-M group 9 and an unidentifiable combination designated CTX-M group G2/Gx. A sample of 46/97 (47.4%) CTX-M-positive E. coli isolates was chosen for PFGE and demographic information regarding the source of the isolates was collated. Eight E. coli clusters were identified by PFGE; however, they did not achieve the 85% cut-off to demonstrate clonality. Nitrofurantoin resistance was significantly greater in the E. coli isolates expressing a non-CTX-M group 1 ESBL when compared with the E. coli isolates expressing a CTX-M group 1 ESBL.<p></p> <b>Conclusions</b> As seen in other British studies, blaCTX-M has become the predominant ESBL type in Glasgow, Scotland. The PFGE results show that four different CTX-M groups appear to be circulating in the community and within all four hospitals in the locality. There is little correlation between strain genotype and CTX-M group, thus it is unlikely that cross-infection alone is the driver. It is possible that plasmid migration of CTX-M genes within the E. coli population is occurring.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Boyes, Dr John and Khanna, Dr Nitish
• Authors: Khanna, N., Boyes, J., Lansdell, P.M., Hamouda, A., and Amyes, S.G.B.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Journal of Antimicrobial Chemotherapy
• Journal Abbr.: J. Antimicrob. Chemother.
• ISSN: 0305-7453
• ISSN (Online): 1460-2091
• Published Online: 14 December 2011