Shang Ke, Gao Yuanji, Du Jiangbo, Liu Chang, Dai Jinglei, Zhang Junfeng, Jia Yanyan, Yu Zuhua, Chen Songbiao, Liu Zhongyu
The 989th Hospital of the Joint Logistics Support Force of Chinese People's Liberation Army, Luoyang, China.
Laboratory of Functional Microbiology and Animal Health, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China.
Front Cell Infect Microbiol. 2025 Jun 11;15:1578027. doi: 10.3389/fcimb.2025.1578027. eCollection 2025.
(ica) cause mastitis in sheep, acute sepsis in newborn lambs, and co-infections with various pathogens, leading to bovine respiratory disease syndrome (BRDS), these infections have resulted in significant economic losses to both domestic and international farming industries. An in-depth understanding of the pathogenic mechanisms of is crucial for the prevention and control of this disease. Outer membrane vesicles (OMVs) play a vital role in bacterial pathogenesis, serving as key mediators of interactions between Gram-negative bacteria and their hosts. However, the specific role of OMVs in the pathogenic process of remains poorly understood. To address this, we isolated OMVs from the Type A5 strain (MH-5) using ultracentrifugation and subsequently characterized their secretory properties, protein composition, and immunogenicity through electron microscopy, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and cellular experiments. The electron microscopy results indicated that the MH-5 strain secreted OMVs under natural growth conditions. Proteomic and bioinformatics analyses revealed that these OMVs contained 282 proteins, with significant enrichment in proteins related to immunity, iron metabolism, and catalytic activity. Cellular experiments demonstrated that, compared to the control group, the OMVs group exhibited a significant increase in the mRNA expression of IL-1β, IL-6, and TNF-α, with secretion levels increasing in a dose-dependent manner, thereby enhancing the inflammatory response. These findings lay the groundwork for further exploration of the role of OMVs in the pathogenesis of and provide insights for the development of effective vaccines and antibiotics against this pathogen.
（ica）可导致绵羊乳腺炎、新生羔羊急性败血症以及与多种病原体的混合感染，进而引发牛呼吸道疾病综合征（BRDS），这些感染给国内外养殖业造成了重大经济损失。深入了解（ica）的致病机制对于该病的防控至关重要。外膜囊泡（OMVs）在细菌致病过程中起着至关重要的作用，是革兰氏阴性菌与其宿主之间相互作用的关键介质。然而，OMVs在（ica）致病过程中的具体作用仍知之甚少。为了解决这一问题，我们通过超速离心从（ica）A5型菌株（MH - 5）中分离出OMVs，并随后通过电子显微镜、液相色谱 - 串联质谱（LC - MS/MS）和细胞实验对其分泌特性、蛋白质组成和免疫原性进行了表征。电子显微镜结果表明，MH - 5菌株在自然生长条件下分泌OMVs。蛋白质组学和生物信息学分析显示，这些OMVs含有282种蛋白质，在与免疫、铁代谢和催化活性相关的蛋白质中显著富集。细胞实验表明，与对照组相比，OMVs组中IL - 1β、IL - 6和TNF - α的mRNA表达显著增加，分泌水平呈剂量依赖性增加，从而增强了炎症反应。这些发现为进一步探索OMVs在（ica）致病机制中的作用奠定了基础，并为开发针对该病原体的有效疫苗和抗生素提供了见解。
