Jayarao B M, Henning D R
Minnesota-South Dakota Dairy Food Research Center, Department of Dairy Science, South Dakota State University, Brookings 57007-0647, USA.
J Dairy Sci. 2001 Oct;84(10):2157-62. doi: 10.3168/jds.S0022-0302(01)74661-9.
Bulk tank milk from 131 dairy herds in eastern South Dakota and western Minnesota was examined for the presence of for foodborne pathogens. Campylobacter jejuni, shiga-toxin producing Escherichia coli, Listeria monocytogenes, Salmonella spp., and Yersinia enterocolitica were detected in 9.2, 3.8, 4.6, 6.1, and 6.1% of bulk tank milk samples, respectively. Thirty-five of 131 (26.7%) bulk tank milk samples contained one or more species of pathogenic bacteria. Isolates of Salmonella belonged to group D (n = 4), B (n = 2), C (n = 1), and E (n = 1) "O" serogroups. All six isolates of Listeria monocytogenes were identified as O antigen type 1. Four of five isolates of E. coli encoded for the shiga-toxin 2 gene, while one strain encoded for the shiga-toxin 1 gene. Escherichia coli O157:H7 was not isolated from bulk tank milk samples. Based on autoagglutination testing, it was inferred that all eight isolates of Yersinia enterocolitica were likely to be virulent. Non A-grade (manufacturing grade) raw milk producers were at a higher risk (odd's ratio, 4.98; confidence interval, 1.96 to 12.22) of having one or more pathogens in their bulk tank milk than were Grade A producers. It was observed that 21 of 79 (26.6%) dairy producers who consumed raw milk had one or more pathogenic bacteria in their bulk tank milk. The findings of the study warrant the need for educational programs for dairy producers about the risks associated with consumption of raw milk.
对南达科他州东部和明尼苏达州西部131个奶牛场的散装罐奶进行了食源性病原体检测。空肠弯曲菌、产志贺毒素大肠杆菌、单核细胞增生李斯特菌、沙门氏菌属和小肠结肠炎耶尔森菌在散装罐奶样品中的检出率分别为9.2%、3.8%、4.6%、6.1%和6.1%。131个散装罐奶样品中有35个（26.7%）含有一种或多种病原菌。沙门氏菌分离株属于D组（n = 4）、B组（n = 2）、C组（n = 1）和E组（n = 1）“O”血清群。所有6株单核细胞增生李斯特菌分离株均被鉴定为O抗原1型。5株大肠杆菌分离株中有4株编码志贺毒素2基因，1株编码志贺毒素1基因。未从散装罐奶样品中分离出大肠杆菌O157:H7。基于自身凝集试验，推断所有8株小肠结肠炎耶尔森菌分离株可能具有致病性。非A级（生产级）原料奶生产商的散装罐奶中含有一种或多种病原体的风险（优势比，4.98；置信区间，1.96至12.22）高于A级生产商。据观察，79名饮用原料奶的奶农中有21名（26.6%）的散装罐奶中含有一种或多种病原菌。该研究结果表明有必要为奶农开展关于饮用原料奶相关风险的教育项目。
