Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Taian, 201718, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Taian, 201718, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Taian, 271018, China.
Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Taian, 201718, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Taian, 201718, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Taian, 271018, China.
Microb Pathog. 2024 Oct;195:106816. doi: 10.1016/j.micpath.2024.106816. Epub 2024 Jul 19.
Salmonella is a zoonotic pathogen posing a serious risk to the farming industry and public health due to food animals serving as reservoirs for future contamination and spread of Salmonella. The present study is designed to monitor the contamination status of Salmonella in duck farms and the main control points during breeding. 160 strains of duck-derived Salmonella were isolated from the 736 samples (cloacal swabs, feces, water, feed, soil, air and dead duck embryos) collected in southwest Shandong Province and the province's surrounding area. The percentage of Salmonella-positive samples collected was 21.74 % (160/736), and the greatest prevalence from duck embryo samples (40.00 %, 36/90). These Salmonella were classified into 23 serotypes depending on their O and H antigens, in which S. Typhimurium (30.15 %), S. Kottbus (13.97 %) and S. Enteritidis (10.29 %) were the prevailing serotypes. Subsequently, the molecular subtyping was done. Clustered regularly interspaced short palindromic repeats (CRISPR) analysis showed that 41 strains of S. Typhimurium and 14 strains of S. Enteritidis were classified into 13 and 3 genotypes, respectively. 19 S. Kottbus isolates from different sources featured ST1546, ST198, ST321, and ST1690 by multilocus sequence typing (MLST) analysis, among which ST1546 belongs to S. Kottbus was a new ST. The minimum spanning tree analysis based on the two CRISPR loci and seven MLST loci from all S. Typhimurium, S. Enteritidis and S. Kottbus isolates revealed that duck embryos, feed and water were key control points to the spread of Salmonella along the breeding chain. Meanwhile, the emergence of S. Kottbus in duck flocks was considered a potential public health hazard.
本研究旨在监测山东省西南部及周边地区鸭场养殖过程中沙门氏菌的污染状况和主要控制环节。从采集的 736 份（泄殖腔拭子、粪便、水、饲料、土壤、空气和死胚鸭）样品中分离出 160 株鸭源沙门氏菌，阳性率为 21.74%（160/736），其中鸭胚样品阳性率最高（40.00%，36/90）。根据 O 抗原和 H 抗原，这些沙门氏菌分为 23 个血清型，其中鼠伤寒沙门氏菌（30.15%）、科特布斯沙门氏菌（13.97%）和肠炎沙门氏菌（10.29%）为优势血清型。随后进行分子亚型分析。聚类规则间隔短回文重复序列（CRISPR）分析显示，41 株鼠伤寒沙门氏菌和 14 株肠炎沙门氏菌分别分为 13 种和 3 种基因型。19 株不同来源的科特布斯沙门氏菌经多位点序列分型（MLST）分析分为 ST1546、ST198、ST321 和 ST1690，其中 ST1546 属于科特布斯沙门氏菌的新 ST 型。基于所有鼠伤寒沙门氏菌、肠炎沙门氏菌和科特布斯沙门氏菌分离株的两个 CRISPR 基因座和 7 个 MLST 基因座的最小生成树分析表明，鸭胚、饲料和水是沙门氏菌沿养殖链传播的关键控制点。同时，鸭群中出现科特布斯沙门氏菌被认为是潜在的公共卫生危害。
