Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Pennsylvania 19348, USA.
J Dairy Sci. 2013 Sep;96(9):5756-61. doi: 10.3168/jds.2012-6499. Epub 2013 Jun 28.
A survey was conducted on 13 dairies to determine the occurrence of 5 animal-borne pathogens (Salmonella enterica, Escherichia coli O157:H7, Campylobacter jejuni, Mycobacterium avium ssp. paratuberculosis, and Cryptosporidium parvum) and their distributions across farm elements (feces, bedding, milk filters, stored manure, field soil, and stream water). Presence of C. parvum was measured only in feces and stored manure. All but one farm were positive for at least one pathogen species, and 5 farms were positive for 3 species. Escherichia coli O157:H7 was detected on 6 farms and in all farm elements, including milk filters. Mycobacterium avium ssp. paratuberculosis was detected on 10 of 13 farms and in all farm elements except for milk filters. Salmonella enterica and C. jejuni were detected at lower frequencies and were not identified in soil, stream water, or milk filters on any of the 13 farms. Cryptosporidium parvum was detected in feces but not in stored manure. Stored manure had the highest occurrence of pathogens (73%), followed by feces (50%), milk filters, bedding, soil, and water (range from 23 to 31%). Association of pathogen presence with farm management factors was examined by t-test; however, the small number of study farms and samples may limit the scope of inference of the associations. Pathogens had a higher prevalence in maternity pen bedding than in calf bedding, but total pathogen occurrence did not differ in calf compared with lactating cow feces or in soils with or without manure incorporation. Herd size and animal density did not appear to have a consistent effect on pathogen occurrence. The extent of pathogen prevalence and distribution on the farms indicates considerable public health risks associated with not only milk and meat consumption and direct animal contact, but also potential dissemination of the pathogens into the agroecosystem.
对 13 家奶牛场进行了一项调查，以确定 5 种动物源性病原体（沙门氏菌、大肠杆菌 O157：H7、空肠弯曲菌、禽分枝杆菌副结核亚种和微小隐孢子虫）的发生情况及其在农场要素（粪便、垫料、牛奶过滤器、储存的粪便、田间土壤和溪流）中的分布。仅在粪便和储存的粪便中检测到微小隐孢子虫。除了一个农场外，所有其他农场都至少有一种病原体呈阳性，有 5 个农场有 3 种病原体呈阳性。在 6 个农场和所有农场要素（包括牛奶过滤器）中检测到大肠杆菌 O157：H7。在 13 个农场中的 10 个农场和所有农场要素（除了牛奶过滤器）中检测到禽分枝杆菌副结核亚种。沙门氏菌和空肠弯曲菌的检出率较低，在 13 个农场中的任何一个农场的土壤、溪流或牛奶过滤器中均未检测到。微小隐孢子虫仅在粪便中检测到，而在储存的粪便中未检测到。储存的粪便中病原体的检出率最高（73%），其次是粪便（50%）、牛奶过滤器、垫料、土壤和水（范围为 23%至 31%）。通过 t 检验检查了病原体存在与农场管理因素的关系；然而，研究农场和样本数量较少可能限制了关联推断的范围。与小牛垫料相比，产仔围栏垫料中的病原体更为普遍，但小牛粪便中的总病原体发生率与哺乳期奶牛粪便或有无粪便掺入的土壤中的病原体发生率没有差异。畜群规模和动物密度似乎对病原体的发生没有一致的影响。农场中病原体的流行程度和分布表明，不仅与牛奶和肉类消费以及直接动物接触有关，而且还与病原体潜在地传播到农业生态系统有关，存在相当大的公共卫生风险。
