Davis Margaret A, Hancock Dale D, Rice Daniel H, Call Douglas R, DiGiacomo Ronald, Samadpour Mansour, Besser Thomas E
Field Disease Investigation Unit, Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA 99164-6610, USA.
Vet Microbiol. 2003 Sep 1;95(3):199-210. doi: 10.1016/s0378-1135(03)00159-7.
Feed has been reported as a vehicle for transmission of Salmonella enterica in cattle and several lines of evidence suggest that feed can be a vehicle for transmitting Escherichia coli O157:H7 as well. To show whether microbial contamination of feeds could contribute to the populations of S. enterica and E. coli O157:H7 on a farm, we compared isolates from feed samples to bovine fecal isolates from the same farm using pulsed-field gel electrophoresis (PFGE). Four of 2365 component feed samples (0.2%) and 1 of 226 feed mill samples (0.4%) were positive for E. coli O157:H7. Twenty of 2405 (0.8%) component feed samples and none of 226 feed mill samples were positive for Salmonella. PFGE profiles from E. coli O157:H7 isolated from a component feed sample closely resembled that from a fecal isolate collected later from the same farm, and a similar observation was made of a Salmonella Tyhpimurium isolate from component feed on another farm. There were indistinguishable PFGE profiles from component feed Salmonella Tyhpimurium DT104 isolates and fecal isolates from the same farm. These results provide evidence for a role of cattle feed in transmission of E. coli O157:H7; S. enterica; cattle-bacteria.
据报道，饲料是牛肠道沙门氏菌传播的载体，并且有几条证据表明饲料也可能是大肠杆菌O157:H7传播的载体。为了证明饲料的微生物污染是否会导致农场中肠道沙门氏菌和大肠杆菌O157:H7的数量增加，我们使用脉冲场凝胶电泳（PFGE）将饲料样本中的分离株与同一农场的牛粪便分离株进行了比较。2365份配合饲料样本中有4份（0.2%）和226份饲料厂样本中有1份（0.4%）的大肠杆菌O157:H7呈阳性。2405份配合饲料样本中有20份（0.8%）的沙门氏菌呈阳性，而226份饲料厂样本中均未检测到阳性。从一份配合饲料样本中分离出的大肠杆菌O157:H7的PFGE图谱与后来从同一农场采集的粪便分离株的图谱非常相似，并且在另一个农场对配合饲料中的鼠伤寒沙门氏菌分离株也有类似的观察结果。来自同一农场的配合饲料鼠伤寒沙门氏菌DT104分离株和粪便分离株的PFGE图谱无法区分。这些结果为牛饲料在大肠杆菌O157:H7、肠道沙门氏菌传播中的作用提供了证据；牛-细菌。
