Dueñas Fernando, Rivera Dácil, Toledo Viviana, Tardone Rodolfo, Hervé-Claude Luis P, Hamilton-West Christopher, Switt Andrea I Moreno
Escuela de Medicina Veterinaria, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello, Santiago, Chile 8320000.
Departamento de Ciencias Clínicas, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile 8820808.
J Dairy Sci. 2017 Mar;100(3):2196-2200. doi: 10.3168/jds.2016-11569. Epub 2016 Dec 29.
Salmonella enterica can cause disease and mortality in calves. This pathogen is also a zoonosis that can be transmitted by animal contact or by food. The prevalence of Salmonella in dairy farms has been reported to range from 0 to 64%, and, due to the diversity of Salmonella serovars that can be circulating, Salmonella is an important concern for dairy production. Bacteriophages that infect Salmonella have been documented to be abundant and widely distributed in the dairy environment. The current study investigated the diversity of Salmonella serovars and Salmonella phages in 8 dairy farms with a history of diarrhea in southern Chile. A total of 160 samples from sick calves, healthy calves, and the environment were analyzed for Salmonella and phage. Isolated phages were characterized and classified by their host range using a panel of 26 Salmonella isolates representing 23 serovars. Host ranges were classified according to lysis profiles (LP) and their spatial distribution was mapped. Salmonella-infecting phages were identified, but none of the 160 samples were positive for Salmonella. A total of 45 phage isolates were obtained from sick calves (11), healthy calves (16), or the environment (18). According to their host range, 19 LP were identified, with LP1 being the most common on all 8 farms; LP1 represents phages that only lyse serogroup D Salmonella. The identification of Salmonella phages but not Salmonella in the same samples could suggest that these phages are controlling Salmonella in these farms.
肠炎沙门氏菌可导致犊牛发病和死亡。这种病原体也是一种人畜共患病，可通过动物接触或食物传播。据报道，奶牛场中沙门氏菌的流行率在0%至64%之间，并且由于可能传播的沙门氏菌血清型的多样性，沙门氏菌是奶牛生产中的一个重要问题。已证明感染沙门氏菌的噬菌体在奶牛场环境中数量丰富且分布广泛。本研究调查了智利南部8个有腹泻病史的奶牛场中沙门氏菌血清型和沙门氏菌噬菌体的多样性。对来自患病犊牛、健康犊牛和环境的总共160个样本进行了沙门氏菌和噬菌体分析。使用一组代表23个血清型的26株沙门氏菌分离株，根据其宿主范围对分离出的噬菌体进行表征和分类。根据裂解谱（LP）对宿主范围进行分类，并绘制其空间分布图。鉴定出了感染沙门氏菌的噬菌体，但160个样本中没有一个沙门氏菌呈阳性。总共从患病犊牛（11个）、健康犊牛（16个）或环境（18个）中获得了45株噬菌体分离株。根据其宿主范围，鉴定出19种LP，其中LP1在所有8个农场中最为常见；LP1代表仅裂解D血清群沙门氏菌的噬菌体。在相同样本中鉴定出沙门氏菌噬菌体但未鉴定出沙门氏菌，这可能表明这些噬菌体在这些农场中控制着沙门氏菌。
