Möbius Petra, Liebler-Tenorio Elisabeth, Hölzer Martin, Köhler Heike
Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), Institute of Molecular Pathogenesis, 07743 Jena, Naumburger Str. 96a, Germany.
Friedrich Schiller University Jena, Faculty of Mathematics and Computer Science, RNA Bioinformatics and High Throughput Analysis, 07743 Jena, Leutragraben 1, Germany.
Vet Microbiol. 2017 Mar;201:188-194. doi: 10.1016/j.vetmic.2017.01.026. Epub 2017 Jan 22.
Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis affecting ruminants worldwide. Depending on the MAP-Type (MAP-C or MAP-S, cattle or sheep type), strains differ in virulence and host preference. There is not yet any strong evidence indicating that individual field strains of the same MAP-subgroup exhibit differences in virulence. The aim of this study was to evaluate a potential association between the genotype of individual field strains belonging to the MAP-C group and the presence of macroscopic intestinal lesions characteristic of paratuberculosis in the infected animals. 88 MAP-C isolates were sampled from clinically healthy cows at slaughter. Cows were grouped as A (n=46) with, and B (n=42) without macroscopic intestinal lesions. Sampled cows from both the A and B groups came from different farms and had a similar age distribution. MAP isolates were characterized by MIRU-VNTR and IS900-RFLP analysis. Resulting genotypes were examined for an association with the presence of macroscopic intestinal lesions characteristic of paratuberculosis. MAP isolates from groups A and B exhibited similar strain diversity: 20 and 18 combined genotypes, altogether 32 genotypes. Six of these genotypes were detected in both groups. Although no association was found between individual combined genotypes and presence of macroscopic intestinal lesions, IS900-RFLP-(BstEII)-Type-C1 (the most common type worldwide) was found more often in group A (p<0.01). The data give only weak indication for the existence of differences in virulence among MAP-cattle type isolates. Differences in the development and severity of lesions may rather depend on unknown host factors or inoculation dose. Virulence properties of IS900-RFLP-(BstEII)-Type-C1 isolates should be examined in more detail.
副结核分枝杆菌鸟亚种（MAP）是全球范围内影响反刍动物的副结核病的病原体。根据MAP类型（MAP-C或MAP-S，牛型或羊型），菌株在毒力和宿主偏好方面存在差异。目前尚无确凿证据表明同一MAP亚组的单个田间菌株在毒力上存在差异。本研究的目的是评估属于MAP-C组的单个田间菌株的基因型与感染动物中副结核病特征性宏观肠道病变的存在之间的潜在关联。从屠宰时临床健康的奶牛中采集了88株MAP-C分离株。奶牛被分为A组（n = 46）有宏观肠道病变和B组（n = 42）无宏观肠道病变。A组和B组的采样奶牛来自不同农场，年龄分布相似。通过MIRU-VNTR和IS900-RFLP分析对MAP分离株进行特征鉴定。检查所得基因型与副结核病特征性宏观肠道病变的存在之间的关联。A组和B组的MAP分离株表现出相似的菌株多样性：分别有20种和18种组合基因型，共32种基因型。其中6种基因型在两组中均有检测到。虽然未发现单个组合基因型与宏观肠道病变的存在之间存在关联，但IS900-RFLP-（BstEII）-C1型（全球最常见的类型）在A组中更常出现（p<0.01）。这些数据仅微弱表明MAP牛型分离株之间存在毒力差异。病变发展和严重程度的差异可能更多地取决于未知的宿主因素或接种剂量。应更详细地研究IS900-RFLP-（BstEII）-C1型分离株的毒力特性。
