Iguchi Atsushi, Ueno Yuichi, Hoshinoo Kaori, Okuno Miki, Uemura Ryoko, You Garam, Ogura Yoshitoshi, Takamatsu Daisuke
Department of Animal and Grassland Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.
Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan.
Sci Rep. 2025 Apr 8;15(1):11970. doi: 10.1038/s41598-025-97176-z.
The bovine respiratory disease complex (BRDC) is a global issue affecting dairy and beef farms and is of major concern due to the high morbidity and mortality rates in calves, as well as decreased production it causes, resulting in significant economic losses. Mannheimia haemolytica is one of the secondary pathogens associated with BRDC. M. haemolytica is classified into 12 serotypes based on capsular antigens. In addition to the prevalent serotypes A1, A2, and A6, strains belonging to other serotypes also cause respiratory diseases in cattle and other ruminants, necessitating a method for their rapid and easy identification. In this study, we organized the capsule biosynthesis genes based on genome information from all serotype strains and designed 11 PCR primer pairs targeting serotype-specific genes, which could individually identify serotypes A14/A16, which possess homologous genes, as well as all other serotypes. Additionally, we developed two multiplex PCR kits that include these serotype-specific and M. haemolytica species-specific primers. Specificity testing using reference strains confirmed that these kits can simultaneously and clearly identify both the species and their serotypes. The PCR-based system described here could be a valuable tool for subtyping M. haemolytica strains in epidemiological studies and surveillance efforts in cattle and other reservoir animals. This study also carefully compared and discussed the differences between the capsule synthesis genes of A8 and A14 from previously published and those obtained in this study.
牛呼吸道疾病综合征（BRDC）是一个影响奶牛场和肉牛场的全球性问题，由于犊牛的高发病率和死亡率以及它所导致的生产下降，造成了重大经济损失，因而备受关注。溶血曼氏杆菌是与BRDC相关的继发性病原体之一。溶血曼氏杆菌根据荚膜抗原分为12个血清型。除了流行的A1、A2和A6血清型外，其他血清型的菌株也会引起牛和其他反刍动物的呼吸道疾病，因此需要一种快速简便的鉴定方法。在本研究中，我们根据所有血清型菌株的基因组信息整理了荚膜生物合成基因，并设计了11对针对血清型特异性基因的PCR引物对，这些引物对可以分别鉴定具有同源基因的A14/A16血清型以及所有其他血清型。此外，我们还开发了两种多重PCR试剂盒，其中包括这些血清型特异性引物和溶血曼氏杆菌种特异性引物。使用参考菌株进行的特异性测试证实，这些试剂盒可以同时并清晰地鉴定出菌种及其血清型。本文所述的基于PCR的系统可能是牛和其他宿主动物流行病学研究和监测工作中对溶血曼氏杆菌菌株进行亚型分类的宝贵工具。本研究还仔细比较并讨论了先前发表的A8和A14荚膜合成基因与本研究中获得的基因之间的差异。
