Survival in the environment is a possible key factor for the expansion of Escherichia coli strains producing extended-spectrum beta-lactamases
2014 (English)In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 122, no 1, 59-67 p.Article in journal (Refereed) Published
Acquired resistance to cephalosporins in Enterobacteriaceae is a global problem. After an outbreak at Uppsala University Hospital of extended-spectrum -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, -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.
Place, publisher, year, edition, pages
2014. Vol. 122, no 1, 59-67 p.
E-coli, AmpC, ESBL, environment, virulence genes, plasmids
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-216726DOI: 10.1111/apm.12102ISI: 000328909100008OAI: oai:DiVA.org:uu-216726DiVA: diva2:691212