Pennsylvania Veterinary Laboratory, Pennsylvania Department of Agriculture, Harrisburg, PA.
J Vet Diagn Invest. 2021 Mar;33(2):375-378. doi: 10.1177/1040638721991118. Epub 2021 Feb 1.
Johne's disease (paratuberculosis) is an economically important disease of cattle worldwide. The disease is caused by subsp. (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 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.
副结核病（副结核分枝杆菌病）是一种在全球范围内对牛具有重要经济意义的疾病。该病由副结核分枝杆菌亚种（MAP）引起，是一种苛刻的革兰氏阳性细菌。鉴于快速检测周转时间和敏感性及特异性可与粪便培养相媲美，聚合酶链反应（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，由于 MAP 复杂的富含脂质的细胞壁以及粪便中存在 PCR 抑制剂，因此高效提取 DNA 以进行 MAP 的灵敏检测受到影响。我们评估了一种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 基因 PCR 结合用于从牛粪便样本中检测 MAP，该方法正确鉴定了从国家兽医服务实验室获得的所有阴性（13/13）和阳性（35/35）能力验证样本。此外，所有 6 个阴性和 51 个阳性诊断样本也都得到了正确分类。
