Fernández-Silva J A, Abdulmawjood A, Bülte M
Institute of Veterinary Food Sciences, Justus Liebig University Giessen, Frankfurter Straße 92, 35392 Giessen, Germany.
Vet Med Int. 2011;2011:352561. doi: 10.4061/2011/352561. Epub 2011 Jun 15.
The objective of this study was the serological, bacteriological and molecular diagnosis, as well as the molecular characterization of Mycobacterium avium subsp. paratuberculosis (Map) in adult cows of five Colombian dairy herds. Serum samples were tested by an indirect absorbed enzyme-linked immunosorbent assay (ELISA-C). All fecal samples were tested by pooled culture. After that, fecal samples of Map positive pools were tested individually by culture and polymerase chain reaction (PCR). In one herd, slurry and tissue samples from one animal were also taken and tested by PCR and culture. Map isolates were analyzed by the Multilocus Short Sequence Repeat (MLSSR) and the Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats (MIRU-VNTR) methods. ELISA produced positive results in 1.8% (6/329) of the animals and 40% (2/5) of the herds. Four fecal, two tissue, and two slurry samples from a herd were Map positive by culture and PCR. MLSSR and MIRU-VNTR revealed two different strain profiles among eight Map isolates recovered. This study reports the first molecular characterization of Map in one dairy herd in Colombia, the limitations for individual diagnosis of subclinical Map infections in cattle, and the usefulness of pooled fecal samples and environmental sampling for Map diagnosis.
本研究的目的是对哥伦比亚五个奶牛场成年母牛的鸟分枝杆菌副结核亚种（Map）进行血清学、细菌学和分子诊断，以及分子特征分析。血清样本通过间接吸附酶联免疫吸附测定（ELISA-C）进行检测。所有粪便样本通过混合培养进行检测。之后，对Map阳性混合样本的粪便样本分别进行培养和聚合酶链反应（PCR）检测。在一个牛群中，还采集了一头动物的粪便和组织样本，并通过PCR和培养进行检测。通过多位点短序列重复（MLSSR）和分枝杆菌散布重复单位-可变数目串联重复序列（MIRU-VNTR）方法对Map分离株进行分析。ELISA在1.8%（6/329）的动物和40%（2/5）的牛群中产生了阳性结果。通过培养和PCR检测，一个牛群的四个粪便样本、两个组织样本和两个粪便样本呈Map阳性。MLSSR和MIRU-VNTR在回收的八个Map分离株中揭示了两种不同的菌株谱。本研究报告了哥伦比亚一个奶牛场Map的首次分子特征分析、牛亚临床Map感染个体诊断的局限性，以及混合粪便样本和环境采样对Map诊断的实用性。
