Division of Epidemiology and Microbial Genomics, National Food Institute, Technical University of Denmark, Denmark.
Int J Food Microbiol. 2013 Sep 2;166(2):231-7. doi: 10.1016/j.ijfoodmicro.2013.07.014. Epub 2013 Jul 26.
Faecal contamination of carcasses in the slaughterhouse is generally considered to be the source of Salmonella on pork. In this study the hygiene indicator Escherichia coli is used to quantify faecal contamination of carcasses and it is hypothesized that it can be used to predict the quantitative carcass contamination with Salmonella, when the distribution of Salmonella concentrations in faeces is known. Paired pig sample data (faecal samples and carcass swabs) were obtained from five slaughterhouses and analysed for prevalence and concentrations of E. coli and Salmonella. A simple model was developed to describe the faecal contamination of carcasses using the E. coli data. The E. coli results suggested different hygiene performances in different slaughterhouses, and showed that a model assuming that carcasses are predominantly contaminated by their own faeces was not appropriate. Observed Salmonella prevalences were low (on average 1.9% on carcasses) and between slaughterhouses the prevalences ranked differently than the hygiene performance based on the E. coli data suggested. Also, the Salmonella concentrations predicted using E. coli as a faecal indicator were lower than the observed Salmonella concentrations. It is concluded that the faecal carriage of Salmonella together with the faecal contamination of carcasses, as predicted from E. coli data in the animal faeces and hygiene performance of the slaughterhouse, is not sufficient to explain carcass contamination with Salmonella. Our extensive data set showed that other factors than the observed faecal carriage of Salmonella by the individual animals brought to slaughter, play a more important role in the Salmonella carcass contamination of pork.
屠宰场中胴体的粪便污染通常被认为是猪肉中沙门氏菌的来源。在这项研究中，卫生指标大肠杆菌被用来量化胴体的粪便污染，并假设当粪便中沙门氏菌浓度的分布已知时，它可以用于预测沙门氏菌定量污染胴体的情况。从五个屠宰场获得了配对的猪样本数据（粪便样本和胴体拭子），并对大肠杆菌和沙门氏菌的流行率和浓度进行了分析。使用大肠杆菌数据开发了一个简单的模型来描述胴体的粪便污染。大肠杆菌的结果表明不同屠宰场的卫生性能不同，并且表明假设胴体主要被其自身的粪便污染的模型是不合适的。观察到的沙门氏菌流行率较低（平均胴体上为 1.9%），并且在屠宰场之间，流行率的排名与基于大肠杆菌数据的卫生性能所暗示的不同。此外，使用大肠杆菌作为粪便指示物预测的沙门氏菌浓度低于观察到的沙门氏菌浓度。因此，结论是，从动物粪便中的大肠杆菌数据和屠宰场的卫生性能预测的沙门氏菌的粪便携带以及胴体的粪便污染，不足以解释沙门氏菌污染胴体的情况。我们广泛的数据集表明，除了个体动物带到屠宰场的观察到的粪便携带沙门氏菌之外，其他因素在猪肉中沙门氏菌污染胴体方面发挥了更重要的作用。
