Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering College, Pakistan Institute of Engineering and Applied Sciences (NIBGE-C, PIEAS), Faisalabad, 38000, Punjab, Pakistan.
Atta-Ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000, Pakistan.
BMC Genomics. 2023 Sep 14;24(1):546. doi: 10.1186/s12864-023-09626-5.
Haemorrhagic septicaemia (HS) is a highly fatal and predominant disease in livestock, particularly cattle and buffalo in the tropical regions of the world. Pasteurella multocida (P. multocida), serotypes B:2 and E:2, are reported to be the main causes of HS wherein serotype B:2 is more common in Asian countries including Pakistan and costs heavy financial losses every year. As yet, very little molecular and genomic information related to the HS-associated serotypes of P. multocida isolated from Pakistan is available. Therefore, this study aimed to explore the characteristics of novel bovine isolates of P. multocida serotype B:2 at the genomic level and perform comparative genomic analysis of various P. multocida strains from Pakistan to better understand the genetic basis of pathogenesis and virulence.
To understand the genomic variability and pathogenomics, we characterized three HS-associated P. multocida serotype B:2 strains isolated from the Faisalabad (PM1), Peshawar (PM2) and Okara (PM3) districts of Punjab, Pakistan. Together with the other nine publicly available Pakistani-origin P. multocida strains and a reference strain Pm70, a comparative genomic analysis was performed. The sequenced strains were characterized as serotype B and belong to ST-122. The strains contain no plasmids; however, each strain contains at least two complete prophages. The pan-genome analysis revealed a higher number of core genes indicating a close resemblance to the studied genomes and very few genes (1%) of the core genome serve as a part of virulence, disease, and defense mechanisms. We further identified that studied P. multocida B:2 strains harbor common antibiotic resistance genes, specifically PBP3 and EF-Tu. Remarkably, the distribution of virulence factors revealed that OmpH and plpE were not present in any P. multocida B:2 strains while the presence of these antigens was reported uniformly in all serotypes of P. multocida.
This study's findings indicate the absence of OmpH and PlpE in the analyzed P. multocida B:2 strains, which are known surface antigens and provide protective immunity against P. multocida infection. The availability of additional genomic data on P. multocida B:2 strains from Pakistan will facilitate the development of localized therapeutic agents and rapid diagnostic tools specifically targeting HS-associated P. multocida B:2 strains.
出血性败血症（HS）是一种在世界热带地区的家畜中高度致命和主要的疾病，特别是牛和水牛。已报道多杀巴斯德氏菌（P. multocida）血清型 B:2 和 E:2 是 HS 的主要原因，其中血清型 B:2 在包括巴基斯坦在内的亚洲国家更为常见，每年造成沉重的经济损失。迄今为止，关于从巴基斯坦分离的与 HS 相关的 P. multocida 血清型的分子和基因组信息非常有限。因此，本研究旨在从基因组水平上探索新型牛源多杀巴斯德氏菌血清型 B:2 的特征，并对来自巴基斯坦的各种多杀巴斯德氏菌菌株进行比较基因组分析，以更好地了解发病机制和毒力的遗传基础。
为了了解基因组的变异性和病原体组学，我们从巴基斯坦旁遮普省费萨拉巴德（PM1）、白沙瓦（PM2）和奥卡拉（PM3）地区分离了三株与 HS 相关的多杀巴斯德氏菌血清型 B:2 菌株，并对其进行了表征。同时，对其他 9 株来自巴基斯坦的公开来源的多杀巴斯德氏菌菌株和参考菌株 Pm70 进行了比较基因组分析。测序菌株被鉴定为血清型 B，属于 ST-122。这些菌株不含质粒；然而，每个菌株至少含有两个完整的噬菌体。全基因组分析显示，核心基因数量较多，表明与研究基因组非常相似，而核心基因组的很少一部分基因（1%）作为毒力、疾病和防御机制的一部分。我们进一步发现，所研究的多杀巴斯德氏菌 B:2 菌株携带常见的抗生素抗性基因，特别是 PBP3 和 EF-Tu。值得注意的是，毒力因子的分布表明，OmpH 和 plpE 不存在于任何多杀巴斯德氏菌 B:2 菌株中，而这些抗原在所有多杀巴斯德氏菌血清型中都均匀存在。
本研究的结果表明，在所分析的多杀巴斯德氏菌 B:2 菌株中不存在 OmpH 和 PlpE，它们是已知的表面抗原，可提供针对多杀巴斯德氏菌感染的保护性免疫。巴基斯坦多杀巴斯德氏菌 B:2 菌株的更多基因组数据的可用性将有助于开发针对与 HS 相关的多杀巴斯德氏菌 B:2 菌株的局部治疗剂和快速诊断工具。
