Survival in the environment is a possible key factor for the expansion of Escherichia coli strains producing extended-spectrum β-lactamases
Article first published online: 12 JUN 2013
© 2013 APMIS. Published by John Wiley & Sons Ltd.
How to Cite
Survival in the environment is a possible key factor for the expansion of Escherichia coli strains producing extended-spectrum β-lactamases. APMIS 2013., , , .
- Article first published online: 12 JUN 2013
- Manuscript Accepted: 7 MAR 2013
- Manuscript Revised: 25 JAN 2013
- Manuscript Received: 3 DEC 2012
- Uppsala-Örebro Regional Research Council
- Collaborative Research Council in Uppsala-Västerås
- E. coli ;
- ESBL ;
- virulence genes;
Acquired resistance to cephalosporins in Enterobacteriaceae is a global problem. After an outbreak at Uppsala University Hospital of extended-spectrum β-lactamase (ESBL)-positive Klebsiella pneumoniae producing CTX-M-15, there was a shift from AmpC to ESBL production among Escherichia coli isolates. To explore the basis for this epidemiological shift, 46 E. coli isolates (ESBLs, n = 23; AmpC, n = 23) were characterized with regard to genetic relatedness, β-lactamase, replicon and integron types, antibiotic resistance profiles, and genes encoding virulence factors. In addition, the survival in the environment and on hospital-associated materials was analysed. CTX-M-15 was the most frequent ESBL (78%). Only three (13%) of the AmpC enzymes were harboured on plasmids (CMY-2, DHA-1). Independent of plasmid-mediated beta-lactamase, IncF plasmids predominated and only class I integrons were detected. The ESBL producers carried more virulence genes (p = 0.04), exhibited a broader resistance phenotype (p = 0.01) and survived significantly longer (p = 0.03) on different materials than the AmpC-producing isolates. In conclusion, ESBL-producing isolates had properties which are likely to augment their competitiveness. Apart from antibiotic resistance and virulence factors, extended survival in the environment could be a selective trait for successful ESBL-producing E. coli strains.