Kuhnert Peter, Dubosson Christoph R, Roesch Markus, Homfeld Esther, Doherr Marcus G, Blum Jürg W
Institute of Veterinary Bacteriology, Laenggass-Str. 122, Vetsuisse Faculty, University of Bern, CH-3001 Bern, Switzerland.
Vet Microbiol. 2005 Aug 10;109(1-2):37-45. doi: 10.1016/j.vetmic.2005.02.015.
Cattle are a natural reservoir for Shiga toxigenic Escherichia coli (STEC), however, no data are available on the prevalence and their possible association with organic or conventional farming practices. We have therefore studied the prevalence of STEC and specifically O157:H7 in Swiss dairy cattle by collecting faeces from approximately 500 cows from 60 farms with organic production (OP) and 60 farms with integrated (conventional) production (IP). IP farms were matched to OP farms and were comparable in terms of community, agricultural zone, and number of cows per farm. E. coli were grown overnight in an enrichment medium, followed by DNA isolation and PCR analysis using specific TaqMan assays. STEC were detected in all farms and O157:H7 were present in 25% of OP farms and 17% of IP farms. STEC were detected in 58% and O157:H7 were evidenced in 4.6% of individual faeces. Multivariate statistical analyses of over 250 parameters revealed several risk-factors for the presence of STEC and O157:H7. Risk-factors were mainly related to the potential of cross-contamination of feeds and cross-infection of cows, and age of the animals. In general, no significant differences between the two farm types concerning prevalence or risk for carrying STEC or O157:H7 were observed. Because the incidence of human disease caused by STEC in Switzerland is low, the risk that people to get infected appears to be small despite a relatively high prevalence in cattle. Nevertheless, control and prevention practices are indicated to avoid contamination of animal products.
牛是产志贺毒素大肠杆菌（STEC）的天然宿主，然而，关于其流行率以及与有机或传统养殖方式之间可能存在的关联，目前尚无相关数据。因此，我们通过收集来自60个有机生产（OP）农场和60个综合（传统）生产（IP）农场的约500头奶牛的粪便，研究了瑞士奶牛中STEC特别是O157:H7的流行情况。IP农场与OP农场进行了匹配，在社区、农业区域和每个农场的奶牛数量方面具有可比性。大肠杆菌在富集培养基中过夜培养，随后进行DNA提取，并使用特异性TaqMan分析法进行PCR分析。所有农场均检测到STEC，25%的OP农场和17%的IP农场存在O157:H7。在58%的个体粪便中检测到STEC，4.6%的个体粪便中检测到O157:H7。对250多个参数进行的多变量统计分析揭示了STEC和O157:H存在的几个风险因素。风险因素主要与饲料交叉污染和奶牛交叉感染的可能性以及动物年龄有关。总体而言，未观察到两种农场类型在STEC或O157:H7的流行率或携带风险方面存在显著差异。由于瑞士由STEC引起的人类疾病发病率较低，尽管牛群中的流行率相对较高，但人们感染的风险似乎较小。尽管如此，仍需采取控制和预防措施以避免动物产品受到污染。
