We investigated Salmonella contamination in a slaughterhouse in Jiangsu province (China) by analysing prevalences, loads, and serotypes of Salmonella isolates. In total, 480 samples were collected, with total prevalence of 25.4%. High Salmonella prevalence and load were observed at exsanguination and splitting stages (40.6% and 75.0%; 2.50 ± 0.94 and 2.24 ± 0.72 logMPN/m², respectively), with low prevalence and load at dehairing, flaming, and chilling stages (2.5%, 5.0%, and 15.0%; 1.39 ± 0.42, 1.36 ± 0.31, and 1.38 ± 0.30 logMPN/m², respectively). The Salmonella prevalence and load increased substantially from flaming to splitting stage. Six serovars were represented among 122 Salmonella isolates; S. Derby and S. Typhimurium were predominant and were subtyped using PFGE and CRISPR typing approaches. Fourteen PFGE clusters were identified, with discrimination indices (DI) of 0.929 and 0.976 for S. Derby and S. Typhimurium, respectively. Clusters A1, A2, B, C1, C3, C4, D1, F, I, J, L1, M2, and N2 indicated the isolates from same sampling visit were distributed in same cluster. Cluster D1 and K showed that the strains isolated from splitter and carcass swab-samples were highly resemble. Salmonella serovars with the same CRISPR type were mostly isolated after splitting (represented by Dercr 1, Dercr 2, Dercr 3, Tycr 1, Tycr 2, Tycr 3, Tycr 4, and Tycr 6). Our findings revealed that introduced Salmonella was the major source of swine carcass contamination; three slaughtering steps (polishing, rectal drilling, and evisceration) between flaming and splitting were important risk points for Salmonella release, post-splitting slaughtering processes were major contamination risk points, and the splitter was a contamination factor. Our data suggest routes for controlling Salmonella contamination in a swine slaughterhouse.

我们通过分析沙门氏菌分离株的流行，负荷和血清型，调查了江苏省一家屠宰场中的沙门氏菌污染。总共收集了480个样本，总患病率为25.4％。高沙门氏菌在放血和分割级（40.6％和75.0％; 2.50±0.94和2.24±0.72 logMPN /米观察患病率和负载²分别）中，用在脱毛，燃烧，和冷却阶段低发病率和负载（2.5％ ，5.0％和15.0％；分别为1.39±0.42、1.36±0.31和1.38±0.30 logMPN / m ²）。从燃烧到分裂阶段，沙门氏菌的患病率和负荷显着增加。122名代表中有6名Serovar沙门氏菌分离物；小号。德比和小号。鼠伤菌占主导地位，并使用PFGE和CRISPR分型方法进行亚型分型。鉴定出14个PFGE簇，其S的鉴别指数（DI）为0.929和0.976 。德比和小号。鼠伤寒。聚类A1，A2，B，C1，C3，C4，D1，F，I，J，L1，M2和N2表示来自相同采样访问的分离株分布在同一聚类中。聚类D1和K表明，从分离器和car体拭子样品中分离出的菌株非常相似。沙门氏菌具有相同CRISPR类型的血清型在分裂后大多被分离（由Dercr 1，Dercr 2，Dercr 3，Tycr 1，Tycr 2，Tycr 3，Tycr 4和Tycr 6表示）。我们的研究结果表明，引入沙门氏菌是猪cas体污染的主要来源。燃烧和分解之间的三个屠宰步骤（抛光，直肠钻孔和内脏清除）是沙门氏菌释放的重要风险点，分解后的屠宰过程是主要的污染风险点，而分解器是一个污染因素。我们的数据提出了控制猪屠宰场中沙门氏菌污染的途径。