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BackgroundMultiresistant Gram-negative bacteria producing extended-spectrum β-lactamases (ESBLs) are an emerging problem in human and veterinary medicine. This study focused on comparative molecular characterization of β-lactamase and ESBL-producing Enterobacteriaceae isolates from central Hesse in Germany. Isolates originated from humans, companion animals (dogs and cats) and horses.ResultsIn this study 153 (83.6%) of the human isolates (n = 183) and 163 (91.6%) of the animal isolates (n = 178) were confirmed as ESBL producers by PCR and subsequent sequencing of the PCR amplicons. Predominant ESBL subtypes in human and animal samples were CTX-M-15 (49.3%) and CTX-M-1 (25.8%) respectively. Subtype blaCTX-M-2 was found almost exclusively in equine and was absent from human isolates. The carbapenemase OXA-48 was detected in 19 ertapenem-resistant companion animal isolates in this study. The Plasmid-encoded quinolone resistance (PMQR) gene aac(‘6)-Ib-cr was the most frequently detected antibiotic- resistance gene present in 27.9% of the human and 36.9% of the animal ciprofloxacin-resistant isolates. Combinations of two or up to six different resistance genes (penicillinases, ESBLs and PMQR) were detected in 70% of all isolates investigated. The most frequent species in this study was Escherichia coli (74%), followed by Klebsiella pneumoniae (17.5%), and Enterobacter cloacae (4.2%). Investigation of Escherichia coli phylogenetic groups revealed underrepresentation of group B2 within the animal isolates.ConclusionsIsolates from human, companion animals and horses shared several characteristics regarding presence of ESBL, PMQR and combination of different resistance genes. The results indicate active transmission and dissemination of multi-resistant Enterobacteriaceae among human and animal populations.

BackgroundPost-weaning diarrhoea (PWD), due to Escherichia coli, is an important cause of economic losses to the pig industry primarily as a result of mortality and worsened productive performance. In spite of its relevance, recent data about the prevalence of virulence genes and pathotypes among E. coli isolates recovered from cases of PWD in Europe are scarce.ResultsThis study investigates the prevalence of fimbrial and toxin genes of E. coli by PCR among 280 farms with PWD across Europe. A total of 873 samples collected within the first 48 h after the onset of PWD (occurring 7–21 days post weaning) were submitted to the laboratory for diagnostic purposes. Isolation and identification of E. coli were performed following standard bacteriological methods and PCR assays for the detection of genes encoding for fimbriae (F4, F5, F6, F18 and F41) and toxins (LT, STa, STb and Stx2e). The prevalence of fimbriae and toxins among E. coli isolates from cases of PWD was: F4 (45.1 %), F18 (33.9 %), F5 (0.6 %), F6 (0.6 %), F41 (0.3 %), STb (59.1 %), STa (38.1 %), LT (31.9 %) and Stx2e (9.7 %). E. coli isolates carrying both fimbrial and toxin genes were detected in 52.5 % of the cases (178 out of 339 isolates), with 94.9 % of them being classified as enterotoxigenic E. coli (ETEC). The most common virotype detected was F4, STb, LT.ConclusionsThis study confirms that ETEC is frequently isolated in pig farms with PWD across Europe, with F4- and F18-ETEC variants involved in 36.1 % and 18.2 % of the outbreaks, respectively.

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Out of 174 bovine Shiga toxin-producing Escherichia coli (STEC) strains isolated from diarrheic calves in Germany and Belgium, 122 strains (70.1%) were selected because of their reactivity with the eae (E. coli attaching and effacing gene) probe ECW1-ECW2. One hundred seven of these eae-positive strains (87.7%) harbored stx1 genes, 13 strains (10.7%) had stx2 genes, and 2 strains (1.6%) had both stx genes. The strains displayed 17 different O types, the majority (97 strains [79.5%]) belonging to O5 (5 strains), O26 (21 strains), O111 (13 strains) O118 (36 strains), O145 (9 strains), and O157 (13 strains). In the HEp-2 cell adhesion assay, 99 strains (81.1%) showed a localized adhesion, and 80 strains (65.6%) stimulated actin accumulation, as determined in the fluorescence actin staining test. None of the strains harbored genes coding for bundle-forming pili (bfpA), clearly differentiating them from enteropathogenic E. coli. espB gene sequences were only detectable in 23 (18.9%) of the eae-positive bovine STEC strains. Three different PCRs were established, differentiating between eae sequences of enteropathogenic E. coli strain E2348/69 (O127:H6) and STEC strain EDL933 (O157: H7). Primers matching in the more heterologous downstream eae sequences gave amplicons in only 8 of the 17 O types (O84: