Johne’s disease (paratuberculosis) is an economically important disease of cattle worldwide. The disease is caused by Mycobacterium avium subsp. paratuberculosis (MAP), a fastidious gram-positive bacterium. PCR is increasingly used in diagnostic laboratories for the detection of MAP in fecal samples given the rapid test turnaround time and sensitivity and specificity comparable to fecal culture. However, efficient extraction of DNA for sensitive detection of MAP by PCR is affected by the complex lipid-rich cell wall of MAP and the presence of PCR inhibitors in feces. We evaluated a high-throughput nucleic acid extraction method (MagMAX core nucleic acid purification kit with mechanical lysis module) in conjunction with an hspX gene PCR for the detection of MAP from bovine fecal samples, which resulted in correct identification of all negative (13 of 13) and positive (35 of 35) proficiency test samples obtained from the National Veterinary Services Laboratories. In addition, all 6 negative and 50 of 51 positive diagnostic specimens tested were categorized correctly.

约内氏病（副结核病）是一种在世界范围内对牛具有重要经济意义的疾病。该病由鸟分枝杆菌亚种引起。副结核病（MAP），一种挑剔的革兰氏阳性菌。鉴于快速的测试周转时间以及与粪便培养相当的灵敏度和特异性，PCR 越来越多地用于诊断实验室以检测粪便样本中的 MAP。然而，用于通过 PCR 灵敏检测 MAP 的 DNA 的有效提取受到 MAP 复杂的富含脂质的细胞壁和粪便中 PCR 抑制剂的存在的影响。我们评估了高通量核酸提取方法（带有机械裂解模块的 MagMAX 核心核酸纯化试剂盒）与hspX用于从牛粪便样本中检测 MAP 的基因 PCR，从而正确识别了从国家兽医服务实验室获得的所有阴性（13 个中的 13 个）和阳性（35 个中的 35 个）能力测试样本。此外，测试的 51 个阳性诊断样本中的所有 6 个阴性和 50 个都被正确分类。