Survival of Mycobacterium avium subspecies paratuberculosis in retail pasteurised milk
Survival of Mycobacterium avium subspecies paratuberculosis in retail pasteurised milk
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DOI：
10.1016/j.fm.2018.03.004
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发表时间：
2018-09-01
影响因子：
5.3
通讯作者：
Rees, Catherine E. D.
中科院分区：
文献类型：
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作者：
Gerrard, Zara E.;Swift, Benjamin M. C.;Rees, Catherine E. D.
2014年5月至2015年6月期间，使用噬菌体PCR检测法在英格兰中部地区对零售购买的半脱脂巴氏杀菌奶（n = 368）进行了鸟分枝杆菌副结核亚种（MAP）调查。总体而言，10.3%的总样本中含有活MAP细胞，证实巴氏灭菌法不能完全消除人类通过牛奶接触活MAP。使用噬菌体-PCR测定获得的结果与使用培养或直接PCR的调查结果的比较表明，噬菌体-PCR测定能够检测较低数量的细胞，导致检测到的MAP阳性样品的数量增加。散装牛奶样品中检测到的活菌计数和MAP水平的比较表明，MAP主要不是通过粪便污染引入牛奶中，而是直接进入乳房内的牛奶中。此外，结果检测到MAP的不对称分布存在于体细胞裂解前的牛奶基质中，表明在自然污染的牛奶中的细菌细胞聚集在一起，可能主要位于体细胞内。这后两个结果导致的假设，细胞内的MAP的体细胞内可能会受到保护，防止热灭活过程中巴氏杀菌，占零售牛奶中检测到的MAP的低水平的存在。(C)2018爱思唯尔有限公司版权所有
A survey of retail purchased semi-skimmed pasteurised milk (n = 368) for Mycobacterium avium subspecies paratuberculosis (MAP) was conducted between May 2014 and June 2015 across the midlands of England using the Phage-PCR assay. Overall, 10.3% of the total samples collected contained viable MAP cells, confirming that pasteurisation is not capable of fully eliminating human exposure to viable MAP through milk. Comparison of the results gained using the Phage-PCR assay with the results of surveys using either culture or direct PCR suggest that the phage-PCR assay is able to detect lower numbers of cells, resulting in an increase in the number of MAP-positive samples detected. Comparison of viable count and levels of MAP detected in bulk milk samples suggest that MAP is not primarily introduced into the milk by faecal contamination but rather are shed directly into the milk within the udder. In addition results detected an asymmetric distribution of MAP exists in the milk matrix prior to somatic cell lysis, indicating that the bacterial cells in naturally contaminated milk are clustered together and may primarily be located within somatic cells. These latter two results lead to the hypothesis that intracellular MAP within the somatic cells may be protected against heat inactivation during pasteurisation, accounting for the presence of low levels of MAP detected in retail milk. (C) 2018 Elsevier Ltd. All rights reserved.