Perkins N R, Kelton D F, Hand K J, MacNaughton G, Berke O, Leslie K E
Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada.
J Dairy Sci. 2009 Aug;92(8):3714-22. doi: 10.3168/jds.2009-2030.
The objective of this study was to identify regions at high risk for bacterial water or milk contamination, as well as risk factors associated with high bacteria counts in raw milk in Ontario, Canada. Between 2003 and 2004, the Dairy Farmers of Ontario (DFO) tested water samples from 5,421 farms in Ontario for the presence of Escherichia coli and coliforms. The water samples were collected as "point-of-use" samples, meaning that each sample was taken from a tap or water hose in the milk house as soon as the water was turned on. Routine, monthly raw milk bacterial counts were determined by DFO using BactoScan (Foss, Hillerød, Denmark). BactoScan data were retrieved from DFO for all of the farms with water test results. The prevalence of samples with E. coli and coliforms in water and elevated bacteria counts in raw milk was 13.6, 53.8, and 2.8%, respectively. The spatial analysis, using a scan statistic, revealed 1 coliform and 3 E. coli clusters of contaminated water, but no clusters of elevated milk bacteria counts in raw milk in southern Ontario. The coliform water contamination cluster was the largest, with a radius of approximately 200 km. Regression analysis indicated that risk factors associated with the occurrence of high levels of bacteria in raw milk were elevated average monthly somatic cell count, increased total milk production, cooler seasons of the year, and the presence of E. coli in wash water.
本研究的目的是确定加拿大安大略省存在细菌污染风险较高的水域，以及与原奶中细菌数量偏高相关的风险因素。2003年至2004年期间，安大略省奶农协会（DFO）对安大略省5421个农场的水样进行了大肠杆菌和大肠菌群检测。水样作为“使用点”样本采集，即每个样本在水一打开时就从挤奶房的水龙头或水管中采集。安大略省奶农协会使用BactoScan（丹麦希勒勒德市福斯公司）测定原奶的常规月度细菌计数。从安大略省奶农协会获取了所有有水样检测结果的农场的BactoScan数据。水中含有大肠杆菌和大肠菌群以及原奶中细菌计数偏高的样本比例分别为13.6%、53.8%和2.8%。使用扫描统计量进行的空间分析显示，有1个大肠菌群污染水簇和3个大肠杆菌污染水簇，但安大略省南部原奶中细菌计数偏高的情况没有聚集现象。大肠菌群水污染簇最大，半径约200公里。回归分析表明，与原奶中细菌含量偏高相关的风险因素包括每月平均体细胞计数升高、总产奶量增加、一年中较凉爽的季节以及冲洗水中存在大肠杆菌。
