National survey for Salmonella in pigs, cattle and sheep at slaughter in Great Britain (1999-2000)

Abstract

Aims: The objective of these surveys was to estimate the prevalence of faecal carriage of Salmonella in healthy pigs, cattle and sheep at slaughter, and of pig carcase contamination with Salmonella. These data can be used as a baseline against which future change in Salmonella prevalence in these species at slaughter can be monitored. Methods and Results: In this first randomized National Survey for faecal carriage of Salmonella in slaughter pigs, cattle and sheep in Great Britain, 2509 pigs, 891 cattle and 973 sheep were sampled in 34 pig abattoirs and 117 red meat abattoirs in England, Scotland and Wales. Carriage of Salmonella in 25 g caecal contents was identified in 578 (23AE0% pigs) but in only 134 (5AE3%) of carcase swabs. The predominant Salmonella serovars found in both types of sample were S. Typhimurium (11AE1% caeca, 2AE1% carcases) and S. Derby (6AE3% caeca, 1AE6% carcases). The main definitive phage types (DT) of S. Typhimurium found were DT104 (21AE9% of caecal S. Typhimurium isolates), DT193 (18AE7%), untypable strains (17AE6%), DT208 (13AE3%) and U302 (13AE3%). Three isolates of S. Enteritidis (PTs 13A and 4) and one enrofloxacin-resistant S. Choleraesuis were also isolated. A positive Ômeat-juice ELISAÔ was obtained from 15AE2% of pigs at 40% optical density (O.D.) cut-off level and 35AE7% at 10% cut-off. There was poor correlation between positive ELISA results or carcase contamination and the caecal carriage of Salmonella. The ratio of carcase contamination to caecal carriage rates was highest in abattoirs from the midland region of England and in smaller abattoirs. In cattle and sheep 1 g samples of rectal faeces were tested. Two isolates (i.e. 0AE2%) were recovered from cattle, one each of S. Typhimurium, DT193 and DT12. One sheep sample (0AE1%) contained a Salmonella, S. Typhimurium DT41. In a small subsidiary validation exercise using 25 g of rectal faeces from 174 cattle samples, three (1AE7%) isolates of Salmonella (S. Typhimurium DT104, S. Agama, S. Derby) were found. Conclusions: The carriage rate of Salmonella in prime slaughter cattle and sheep in Great Britain was very low compared with pigs. This suggests that future control measures should be focused on reduction of Salmonella infection on pig farms and minimizing contamination of carcases at slaughter. Significance and Impact of the Study: This work has set baseline figures for Salmonella carriage in these species slaughtered for human consumption in Great Britain. These figures were collected in a representative way, which enables them to be used for monitoring trends and setting control targets.

Molecular insights into farm animal and zoonoticSalmonellainfections

“…Although consumption of contaminated poultry meat and eggs is the primary risk factor for human nontyphoidal salmonellosis, other food-producing animals also pose a threat of zoonotic transmission. For example, serovar Typhimurium is highly prevalent in pig production, with caecal samples of 11.1 per cent of pigs testing positive for S. Typhimurium in a UKwide year-long survey in 1999-2000 (Davies et al 2004). S. Typhimurium has also been associated with lamb, beef and dairy produce, albeit low levels were recorded in the above survey.…”

“…For example, S. Derby was common in UK pigs in 1999-2000 (6.3 per cent of caeca and 1.6 per cent of carcasses) yet in the same period it was rarely observed in humans even though pork products are considered to be an important food vehicle of Salmonella (Davies et al 2004). Similarly, serovars Livingstone, Senftenberg, Agarna, Kedougou and Mbandaka were each responsible for 7-13 per cent of Salmonella-positive tests in chickens in 2007 (compared with 18.8 per cent for Enteritidis), yet none appear in the top 10 serovars causing human disease in the same period (http://www.defra.gov.uk/animalh/ diseases/zoonoses/zoonoses_reports/zoonoses2007.pdf).…”

Prevalence of Salmonella enterica in slaughtered pigs in Serbia: Serotyping, PFGE-genotyping and antimicrobial resistance

“…The occurrence of Salmonella in pig carcasses after processing is different from country to country. The reported percentage of the occurrence was 6% in Italy [15], 0.2% in Switzerland [16], 5.3% in Great Britain [17] and 4.7% in Germany [18] during the period from 2000 to 2003.…”

Serology as an Epidemiological Tool for Salmonella Abortusovis Surveillance in the Wild-Domestic Ruminant Interface

“…The agglutination test is considered the preferred method in export and diagnostic purposes for samples from all species of farm animals (Davies, 2004;OIE, 2010). Our research demonstrated the possibility of performing it alongside the analysis scheme established in the brucellosis official eradication program.…”

“…Flock diagnosis of S. Abortusovis in sheep can be performed by serological tests conducted on a statistically representative sample of the population, but results are not always indicative of active infection (OIE, 2010). These include serum agglutination test (SAT), hemagglutination inhibition, complement fixation, indirect immunofluorescence, gel immunodiffusion, and enzyme-linked immunosorbent assay (ELISA) (Davies, 2004).…”