Wang Kequan, Zhang Chaozheng, Munang'andu Hetron Mweemba, Xu Cheng, Cai Wenlong, Yan Xiaojun, Tao Zhen
School of Fisheries, Zhejiang Ocean University, Zhoushan 316022, China.
Faculty of Biosciences and Aquaculture, Nord University, 8049 Bodø, Norway.
Microorganisms. 2025 May 14;13(5):1129. doi: 10.3390/microorganisms13051129.
is a significant pathogen in marine aquaculture, causing vibriosis in various marine species. This study presents a comparative genomic analysis of two strains, N8T11 and 45T2, which exhibit differing virulence profiles. Virulence assays revealed that N8T11 caused 92% mortality in infected fish, while 45T2 resulted in 0% mortality. Whole-genome sequencing revealed that strain N8T11 harbors five plasmids (pN8T11a, pN8T11b, pN8T11c, pN8T11d and pN8T11e) absent in 45T2, encoding genes potentially linked to virulence, such as siderophore-mediated iron acquisition and stress response mechanisms. Pan-genome analysis highlighted substantial genomic plasticity within , with mobile genetic elements, including plasmids and prophages, contributing to horizontal gene transfer. Conjugation experiments demonstrated that all five N8T11 plasmids can transfer to 45T2 with efficiencies up to 87%, with pN8T11b remaining stable across multiple subcultures, enabling the dissemination of virulence-associated genes. These findings suggest that plasmid-mediated gene transfer plays a role in the virulence variability observed between strains. This study contributes to understanding the genomic factors underlying pathogenicity in and provides insights for future research aimed at controlling vibriosis in aquaculture.
是海水养殖中的一种重要病原体，可导致多种海洋物种发生弧菌病。本研究对两株菌株N8T11和45T2进行了比较基因组分析，这两株菌株表现出不同的毒力特征。毒力试验表明，N8T11在感染的鱼类中导致92%的死亡率，而45T2导致的死亡率为0%。全基因组测序显示，菌株N8T11含有五个45T2中不存在的质粒（pN8T11a、pN8T11b、pN8T11c、pN8T11d和pN8T11e），这些质粒编码可能与毒力相关的基因，如铁载体介导的铁摄取和应激反应机制。泛基因组分析突出了该菌内显著的基因组可塑性，包括质粒和前噬菌体在内的移动遗传元件促进了水平基因转移。接合实验表明，所有五个N8T11质粒都可以以高达87%的效率转移到45T2，其中pN8T11b在多次传代培养中保持稳定，从而使毒力相关基因得以传播。这些发现表明，质粒介导的基因转移在菌株间观察到的毒力变异性中发挥作用。本研究有助于理解该菌致病性的基因组因素，并为未来旨在控制水产养殖弧菌病的研究提供见解。
