Department of Food Science and Technology, Faculty of Agriculture Science, Tabriz Branch, Islamic Azad University, Tabriz, Iran.
Vet Microbiol. 2013 Feb 22;162(1):160-5. doi: 10.1016/j.vetmic.2012.08.026. Epub 2012 Sep 5.
Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease in ruminants and may contribute to Crohn's disease in humans. The aim of this study was to determine the occurrence and quantity of MAP in cattle feces and milk in the Iranian context. In addition, we evaluated the effect of cattle age as well as farming system as risk factors contributing to MAP load. For this, a total sample of 373 consisting of 150 cattle feces (CF), 150 individual cow's milk (ICM), as well as 73 bulk-tank milk (BTM) was collected randomly and regardless of the cattle health status. The samples were assayed using F57 quantitative real-time PCR (qPCR) and culture method. According to the results of qPCR which was found ≈ 10 times more sensitive than culture assay, MAP was detected in 68.66% (103/150) of the CF, 12% (18/150) of the ICM and 52.05% (38/73) of the BTM samples. In contrast to the previous reports, the quantity of MAP in the BTM (2.03-5.97 log cfu/50 ml) was statistically (p<0.01) higher than the ICM (0.90-1.97 log cfu/50 ml). Data suggested a direct relation (p<0.01) between the cattle age and the quantity of MAP in the CF samples, while the relation was not statistically significant (p>0.05) for the ICM. In addition, MAP load in the BTM samples obtained from traditional farms was significantly (p<0.01) higher than that of the industrial ones, while the differences in CF and ICM was not significant (p>0.05).
分支杆菌 avium subsp. 副结核分枝杆菌（MAP）引起反刍动物的 Johne 病，并且可能导致人类的克罗恩病。本研究的目的是确定 MAP 在伊朗牛粪便和牛奶中的发生和数量。此外，我们还评估了牛的年龄以及养殖系统作为导致 MAP 负荷的风险因素的影响。为此，我们随机采集了总共 373 个样本，包括 150 份牛粪便（CF）、150 份个体奶牛奶（ICM）和 73 份大罐奶（BTM），无论牛的健康状况如何。使用 F57 定量实时 PCR（qPCR）和培养方法对样品进行检测。根据 qPCR 的结果，其灵敏度比培养方法高约 10 倍，MAP 在 68.66%（103/150）的 CF、12%（18/150）的 ICM 和 52.05%（38/73）的 BTM 样品中被检测到。与之前的报告相反，BTM 中的 MAP 数量（2.03-5.97 log cfu/50 ml）在统计学上（p<0.01）高于 ICM（0.90-1.97 log cfu/50 ml）。数据表明，CF 样本中 MAP 的数量与牛的年龄之间存在直接关系（p<0.01），而 ICM 中不存在统计学意义（p>0.05）。此外，来自传统农场的 BTM 样本中的 MAP 负荷显著（p<0.01）高于工业农场的，而 CF 和 ICM 之间的差异不显著（p>0.05）。
