Jackson S G, Goodbrand R B, Johnson R P, Odorico V G, Alves D, Rahn K, Wilson J B, Welch M K, Khakhria R
Ontario Ministry of Health, Hamilton Public Health Laboratory, Canada.
Epidemiol Infect. 1998 Feb;120(1):17-20. doi: 10.1017/s0950268897008479.
A 16-month old female child living on an Ontario dairy farm was taken to hospital suffering from bloody diarrhoea. Escherichia coli O157:H7 was isolated from her stool. Initial tests of well water samples were negative for E. coli by standard methods but culture of selected coliform colonies on sorbitol-MacConkey agar led to isolation of E. coli O157:H7. E. coli O157:H7 was also isolated from 63% of cattle on the farm. The E. coli O157:H7 isolates from the child, the water and the cattle were phage type 14, produced verotoxins 1 and 2, and were highly related on analysis by pulsed field gel electrophoresis. The child did not have known direct contact with the cattle and did not consume unpasteurized milk. Hydrogeological investigation revealed the design and location of the well would allow manure-contaminated surface water to flow into the well. This investigation demonstrates that cattle farm well water is a potential source of E. coli O157:H7 which may not be identified by standard screening for E. coli in water.
一名居住在安大略省奶牛场的16个月大女童因血性腹泻被送往医院。从她的粪便中分离出了大肠杆菌O157:H7。井水样本的初步检测按标准方法对大肠杆菌呈阴性，但在山梨醇麦康凯琼脂上对选定的大肠菌群菌落进行培养后，分离出了大肠杆菌O157:H7。农场中63%的牛也分离出了大肠杆菌O157:H7。从该女童、井水和牛身上分离出的大肠杆菌O157:H7属于噬菌体14型，产生1型和2型志贺毒素，经脉冲场凝胶电泳分析，它们高度相关。该女童与牛没有已知的直接接触，也没有饮用未经巴氏消毒的牛奶。水文地质调查显示，水井的设计和位置会使受粪便污染的地表水流入水井。这项调查表明，奶牛场的井水是大肠杆菌O157:H7的一个潜在来源，通过水中大肠杆菌的标准筛查可能无法识别。
