Department of Veterinary Protection of Public Health, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego St 14, 10-719 Olsztyn, Poland.
Department of Veterinary Protection of Public Health, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego St 14, 10-719 Olsztyn, Poland.
J Dairy Sci. 2020 Sep;103(9):8526-8529. doi: 10.3168/jds.2019-16816. Epub 2020 Jul 16.
Mycobacterium avium ssp. paratuberculosis (MAP) is an important pathogen responsible for the chronic progressive granulomatous enteritis known as paratuberculosis. None of the detection methods of MAP infection based on isolation of the bacterium is 100% sensitive or specific. In this article, we describe the comparison of 2 MAP detection methods: direct isolation of genetic material and culture, in individual and pooled milk samples. The genetic types of MAP detected in the samples were also identified. The study was performed in a herd of 321 cows; apparent herd seroprevalence was 3.43%. Seven of 11 individual milk samples from seropositive cows were positive by culture (and confirmed by PCR), whereas all 11 were positive by direct PCR. Of the 62 milk pools from seronegative animals, 15 were positive by culture (and confirmed by PCR) and 13 were positive by direct PCR. Using multiplex PCR and PCR-restriction enzyme analysis (PCR-REA) methods, C (cattle) and S (sheep)-types of mycobacteria were identified. Most of the genetic material tested belonged to C-type. Detection of the MAP type occurring in an infected herd can help track the source of infection. We suggest using genetic material isolated directly from pooled milk samples for quick diagnosis, identification of MAP type, and tracking of infection, without the need to sequence the entire genome.
鸟分枝杆菌亚种副结核（MAP）是一种重要的病原体，可导致慢性进行性肉芽肿性肠炎，即副结核病。基于细菌分离的 MAP 感染检测方法均不是 100%敏感或特异的。本文描述了 2 种 MAP 检测方法的比较：直接分离遗传物质和培养，在个体和混合乳样中。还鉴定了样本中检测到的 MAP 的遗传类型。该研究在一个 321 头奶牛的畜群中进行；明显的畜群血清流行率为 3.43%。11 头血清阳性奶牛的 7 份个体乳样通过培养（并通过 PCR 确认）为阳性，而所有 11 份通过直接 PCR 为阳性。在 62 份来自血清阴性动物的乳样中，有 15 份通过培养（并通过 PCR 确认）为阳性，有 13 份通过直接 PCR 为阳性。使用多重 PCR 和 PCR-限制性内切酶分析（PCR-REA）方法，鉴定了 C（牛）和 S（绵羊）型分枝杆菌。检测到的大多数遗传物质属于 C 型。在感染畜群中检测到的 MAP 类型有助于追踪感染源。我们建议使用直接从混合乳样中分离的遗传物质进行快速诊断、MAP 类型鉴定和感染追踪，而无需对整个基因组进行测序。
