A prevalence study of Salmonella spp., Yersinia spp., Toxoplasma gondii and porcine reproductive and respiratory syndrome virus in UK pigs at slaughter.

An abattoir-based study was undertaken between January and May 2013 to estimate the prevalence of Salmonella spp. and Yersinia spp. carriage and seroprevalence of antibodies to Toxoplasma gondii and porcine reproductive and respiratory syndrome virus (PRRSv) in UK pigs at slaughter. In total, 626 pigs were sampled at 14 abattoirs that together process 80% of the annual UK pig slaughter throughput. Sampling was weighted by abattoir throughput and sampling dates and pig carcasses were randomly selected. Rectal swabs, blood samples, carcass swabs and the whole caecum, tonsils, heart and tongue were collected. Salmonella spp. was isolated from 30·5% [95% confidence interval (CI) 26·5-34·6] of caecal content samples but only 9·6% (95% CI 7·3-11·9) of carcass swabs, which was significantly lower than in a UK survey in 2006-2007. S. Typhimurium and S. 4,[5],12:i:- were the most commonly isolated serovars, followed by S. Derby and S. Bovismorbificans. The prevalence of Yersinia enterocolitica carriage in tonsils was 28·7% (95% CI 24·8-32·7) whereas carcass contamination was much lower at 1·8% (95% CI 0·7-2·8). The seroprevalence of antibodies to Toxoplasma gondii and PRRSv was 7·4% (95% CI 5·3-9·5) and 58·3% (95% CI 53·1-63·4), respectively. This study provides a comparison to previous abattoir-based prevalence surveys for Salmonella and Yersinia, and the first UK-wide seroprevalence estimates for antibodies to Toxoplasma and PRRSv in pigs at slaughter.

Cross-sectional survey of antibiotic resistance in Escherichia coli isolated from diseased farm livestock in England and Wales.

Between 2005 and 2007, E. coli obtained from clinical diagnostic submissions from cattle, goats, pigs and sheep to government laboratories in England and Wales were tested for sensitivity to 16 antimicrobials. Resistance was most commonly observed against ampicillin, streptomycin, sulphonamides and tetracyclines. Resistance levels varied significantly between species, with isolates from cattle frequently showing the highest levels. Verocytotoxigenic E. coli (VTEC) expressed less resistance than non-VTEC. Only 19·3% of non-VTEC and 43·5% of VTEC were susceptible to all antimicrobials, while 47·1% and 30·4%, respectively, were resistant to ⩾5 antimicrobials. The resistance phenotype SSuT was commonly observed, and isolates resistant to third-generation cephalosporins were also identified. We recommend judicious antimicrobial usage in the livestock industry in order to preserve efficacy.

Prevalence of extended-spectrum-ß-lactamase-producing Escherichia coli from pigs at slaughter in the UK in 2013.

OBJECTIVES: To determine the prevalence and types of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli occurring in pigs at slaughter in the UK in 2013. METHODS: Caecal samples from 637 pigs, sampled via a UK-wide monitoring programme in 2013, were enriched overnight in buffered peptone water, before plating to CHROMagar CTX and Oxoid Brilliance ESBL agar. Presumptive ESBL-producing E. coli from both media were tested for ESBL phenotype using MAST ESßL ID discs. Isolates with an ESBL phenotype were examined for the presence of blaCTX-M, blaOXA, blaSHV and blaTEM genes using a multiplex PCR. All blaCTX-M and blaSHV genes identified by PCR were sequenced. RESULTS: A total of 23.4% (95% CI 19.2-27.6) of pigs were positive for ESBL-producing E. coli; 22% (95% CI 17.8-26.1) of the pigs carried E. coli producing CTX-M enzymes [comprising enzyme types 1 (18.7% of pigs), 3 (0.2%), 14 (0.5%), 15 (1.4%), 27 (0.5%), 32 (0.5%) and 55 (0.3%)] and 2.2% (95% CI 0.8-3.6) of the pigs carried E. coli producing SHV-12. Five pigs carried both CTX-M- and SHV-12-producing E. coli as different isolates. There were no statistically significant differences observed between the two medium types in terms of the proportions of each CTX-M enzyme type isolated. CONCLUSIONS: In this UK study, 23.4% of pigs were found to be positive for ESBL-producing E. coli using selective culture media. The use of two different commercially available ESBL isolation media was found to improve the detection of ESBL-producing E. coli.

Verocytotoxin-producing and attaching and effacing activity of Escherichia coli isolated from diseased farm livestock.

Between May 2005 and June 2008, strategically selected isolates of Escherichia coli obtained from clinical submissions to Veterinary Laboratories Agency (VLA) regional laboratories in England and Wales were serogrouped and examined by PCR for verocytotoxin (VT) production and attaching and effacing (eae) genes, both of which are zoonotic determinants. VT-encoding genes were detected in 54 (5.3 per cent) of the 1022 isolates examined. Only one isolate (0.1 per cent) was identified as verocytotoxigenic E coli (VTEC) O157. Non-O157 VTECs were present in 4.7 per cent of isolates from cattle, compared with 7.9 per cent in pigs, 2.3 per cent in sheep and 6.7 per cent in goats. The predominant serogroup identified in cattle was O26 and the predominant serogroup in pigs was O2. Attaching and effacing activity was attributed to 69 (6.8 per cent) of all isolates.