Epidemiology of ESBL-producing Escherichia coli in Sweden 2007-2011.
Clin Microbiol Infect. 2013 Oct 3;
Authors: Brolund A, Edquist PJ, Mäkitalo B, Olsson-Liljequist B, Söderblom T, Tegmark Wisell K, Giske CG
ESBL-producing Enterobacteriaceae are notifiable according to the Swedish communicable disease act since 2007. A major increase of the number of cases has been observed, with 2,099 cases in 2007 and 7,225 cases in 2012. The majority of the isolates are Escherichia coli. Additionally, Swedish data on the prevalence of ESBL-producing invasive isolates of E. coli are available through EARS-Net, and through biannual point prevalence studies, where molecular characterization of isolates from the entire country is carried out. This paper describes major trends in the Swedish epidemiology of ESBL-producing E. coli in the period 2007-2012. Isolates from the point prevalence studies were subjected to antimicrobial susceptibility testing, ESBL genotyping, pulsed-field gel electrophoresis, multi-locus sequence typing and phylogenetic grouping with PCR. The distribution of sequence types, resistance genes, and susceptibility levels were all stable over the three study periods. The dominating resistance gene conferring ESBL was blaCTX -M-15 found in 54-58% of the isolates. ST131 represented 34-38% of the isolates. Other major STs were ST38, ST69, ST405, ST617 and ST648, each representing 2-6% of the isolates. Phylogenetic group B2 was the most common, and observed in 41-47% of the isolates. However, amongst ST131 isolates the B2 phylogenetic group represented 90-98% of the isolates. The most important epidemiological difference seen over time was that the median age of infected women decreased from 62 to 52 years (p<0.0001) and infected men from 67 to 64 years. A potential explanation might be the shift towards a higher proportion of community-acquired infections in individuals lacking comorbidities. This article is protected by copyright. All rights reserved.
PMID: 24118431 [PubMed - as supplied by publisher]