Center for Bioscience and Biotechnology, VNUHCM-University of Science, Ho Chi Minh City, Vietnam.
Vietnam National University, Ho Chi Minh City, Vietnam.
Microb Genom. 2024 May;10(5). doi: 10.1099/mgen.0.001248.
spp. are commonly found in the aquatic environment and have been responsible for motile septicemia (MAS) in striped catfish, resulting in significant economic loss. These organisms also cause a range of opportunistic infections in humans with compromised immune systems. Here, we conducted a genomic investigation of 87 isolates derived from diseased catfish, healthy catfish and environmental water in catfish farms affected by MAS outbreaks in eight provinces in Mekong Delta (years: 2012-2022), together with 25 isolates from humans with bloodstream infections (years: 2010-2020). Genomics-based typing method precisely delineated species while traditional methods such as PCR and MALDI-TOF were unable identify was found to be more prevalent than in both diseased catfish and human infections. sequence type (ST) 656 followed by ST251 were the predominant virulent species-lineages in diseased catfish (43.7 and 20.7 %, respectively), while diverse STs were found in humans with bloodstream infections. There was evidence of widespread transmission of ST656 and ST251 on striped catfish in the Mekong Delta region. ST656 and ST251 isolates carried a significantly higher number of acquired antimicrobial resistance (AMR) genes and virulence factors in comparison to other STs. They, however, exhibited several distinctions in key virulence factors (i.e. lack of type IV pili and enterotoxin in ), AMR genes (i.e. presence of carbapenemase in ), and accessory gene content. To uncover potential conserved proteins of spp. for vaccine development, pangenome analysis has unveiled 2202 core genes between ST656 and ST251, of which 78 proteins were in either outer membrane or extracellular proteins. Our study represents one of the first genomic investigations of the species distribution, genetic landscape, and epidemiology of in diseased catfish and human infections in Vietnam. The emergence of antimicrobial resistant and virulent strains underscores the needs of enhanced genomic surveillance and strengthening vaccine research and development in preventing diseases in catfish and humans, and the search for potential vaccine candidates could focus on core genes encoded for membrane and secreted proteins.
spp. 通常存在于水生环境中，并且是导致条纹鲶鱼游动性败血症（MAS）的原因，导致了重大的经济损失。这些生物体还会导致免疫系统受损的人类发生一系列机会性感染。在这里，我们对 87 株来自受 MAS 暴发影响的鲶鱼养殖场的患病鲶鱼、健康鲶鱼和环境水中的分离株以及 25 株来自患有血流感染的人类的分离株进行了基因组调查（年份：2012-2022 年）。基于基因组的分型方法精确地区分了 spp. ，而传统方法，如 PCR 和 MALDI-TOF 无法识别 spp. 。结果发现，在患病鲶鱼和人类感染中， spp. 比 spp. 更为普遍。序列型（ST）656 紧随其后的是 ST251 是患病鲶鱼中主要的毒力种系（分别为 43.7%和 20.7%），而人类血流感染中则发现了多种 ST。证据表明，ST656 和 ST251 在湄公河三角洲地区的条纹鲶鱼中广泛传播。与其他 ST 相比，ST656 和 ST251 分离株携带的获得性抗菌药物耐药（AMR）基因和毒力因子数量显著更高。然而，它们在关键毒力因子（即缺乏 IV 型菌毛和肠毒素 在 ）、AMR 基因（即存在 carbapenemase 在 ）和辅助基因含量方面存在一些差异。为了发现用于疫苗开发的 spp. 的潜在保守蛋白，泛基因组分析揭示了 ST656 和 ST251 之间的 2202 个核心基因，其中 78 个蛋白位于外膜或细胞外蛋白中。我们的研究代表了对越南患病鲶鱼和人类感染中 spp. 的种分布、遗传景观和流行病学进行的首次基因组调查之一。抗药性和毒力 spp. 菌株的出现突显出加强基因组监测以及加强疫苗研究和开发以预防鲶鱼和人类的 疾病的必要性，并且寻找潜在的疫苗候选物可以集中在编码膜和分泌蛋白的核心基因上。
