摘要
M. bovis is one of the leading causes of respiratory disease and antimicrobial use in cattle. The pathogen is widespread in different cattle industries worldwide, but highest prevalence is found in the veal industry. Knowledge on M. bovis strain distribution over the dairy, beef and veal industries is crucial for the design of effective control and prevention programs, but currently undocumented. Therefore, the present study evaluated the molecular epidemiology and genetic relatedness of M. bovis isolates obtained from Belgian beef, dairy and veal farms, and how these relate to M. bovis strains obtained worldwide. Full genomes of one hundred Belgian M. bovis isolates collected over a 5-year period (2014–2019), obtained from 27 dairy, 38 beef and 29 veal farms, were sequenced by long-read nanopore sequencing. Consensus sequences were used to generate a phylogenetic tree in order to associate genetic clusters with cattle sector, geographical area and year of isolation. The phylogenetic analysis of the Belgian M. bovis isolates resulted in 5 major clusters and 1 outlier. No sector-specific M. bovis clustering was identified. On a world scale, Belgian isolates clustered with Israeli, European and American strains. Different M. bovis clusters circulated for at least 1.5 consecutive years throughout the country, affecting all observed industries. Therefore, the high prevalence in the veal industry is more likely the consequence of frequent purchase from the dairy and beef industry, than that a reservoir of veal specific strains on farm would exist. These results emphasize the importance of biosecurity in M. bovis control and prevention.
摘要译文
牛分枝杆菌是牛呼吸系统疾病和使用抗生素的主要原因之一。该病原体广泛分布于世界各地的各种养牛业中，但在小牛肉业中发现率最高。关于牛乳链霉菌菌株在乳制品，牛肉和小牛肉行业分布的知识对于设计有效的控制和预防计划至关重要，但目前尚无记录。因此，本研究评估了从比利时牛肉，奶牛场和小牛肉场获得的牛分枝杆菌的分子流行病学和遗传相关性，以及它们与世界范围内获得的牛分枝杆菌菌株之间的关系。通过长读纳米孔测序，对在5年内（2014-2019年）从27个奶牛场，38个牛肉场和29个小牛肉场中采集的100个比利时牛分枝杆菌的全基因组进行了测序。为了使遗传集群与牛群，地理区域和分离年份相关联，使用共有序列来生成系统发育树。比利时牛分枝杆菌菌株的系统发育分析导致5个主要簇和1个离群值。没有发现特定部门的牛分枝杆菌。在世界范围内，比利时分离株聚集了以色列，欧洲和美国的毒株。全国不同的牛分枝杆菌丛至少连续1.5年流通，影响了所有观察到的产业。因此，与将存在农场的小牛专用菌种相比，小牛产业中的高流行率很可能是从奶牛和牛肉产业频繁购买的结果。这些结果强调了在牛分枝杆菌控制和预防中生物安全的重要性。
Jade Bokma[1];Nick Vereecke[1];Koen De Bleecker[2];Jozefien Callens[2];Stefaan Ribbens[2];Hans Nauwynck[1];Freddy Haesebrouck[1];Sebastiaan Theuns[1];Filip Boyen[1];Bart Pardon[1]. Phylogenomic analysis of Mycoplasma bovis from Belgian veal, dairy and beef herds[J]. Veterinary Research, 2020,51(1)