PDF(Pubmed)
Abstract：
Aeromonas spp. are commonly found in the aquatic environment and have been responsible for motile Aeromonas 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 Aeromonas 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 Aeromonas species while traditional methods such as aerA PCR and MALDI-TOF were unable identify A. dhakensis. A. dhakensis was found to be more prevalent than A. hydrophila in both diseased catfish and human infections. A. dhakensis sequence type (ST) 656 followed by A. hydrophila 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 ast in A. dhakensis), AMR genes (i.e. presence of imiH carbapenemase in A. dhakensis), and accessory gene content. To uncover potential conserved proteins of Aeromonas 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 Aeromonas in diseased catfish and human infections in Vietnam. The emergence of antimicrobial resistant and virulent A. dhakensis strains underscores the needs of enhanced genomic surveillance and strengthening vaccine research and development in preventing Aeromonas diseases in catfish and humans, and the search for potential vaccine candidates could focus on Aeromonas core genes encoded for membrane and secreted proteins.
摘要：
气单胞菌属。通常在水生环境中发现，并且在条纹cat鱼中引起能动的气单胞菌败血症（MAS），造成了巨大的经济损失。这些生物体还在免疫系统受损的人类中引起一系列机会性感染。这里,我们对87株来自患病鲶鱼的气单胞菌进行了基因组研究，受湄公河三角洲八个省MAS疫情影响的健康鲶鱼和鲶鱼养殖场的环境水（年份：2012-2022年），以及25个来自人类血液感染的分离株（年份：2010-2020年）。基于基因组学的分型方法可以精确地描述气单胞菌的种类，而传统的方法如aerAPCR和MALDI-TOF则无法鉴定达克氏杆菌。在患病的of鱼和人类感染中，发现达克氏杆菌比嗜水气杆菌更普遍。A.dhakensis序列类型（ST）656，其次是A.hydrophilaST251是患病cat鱼的主要毒力物种谱系（43.7％和20.7％，分别)，虽然在血液感染的人类中发现了不同的STs。有证据表明，在湄公河三角洲地区的条纹鲶鱼上广泛传播ST656和ST251。与其他ST相比，ST656和ST251分离株携带的获得性抗微生物耐药性（AMR）基因和毒力因子的数量明显更高。They,然而,在关键毒力因子方面表现出几种差异（即达克曲霉缺乏IV型菌毛和肠毒素），AMR基因（即达克曲霉中存在亚胺碳青霉烯酶），和附属基因含量。揭示气单胞菌属的潜在保守蛋白。用于疫苗开发，pangenome分析揭示了ST656和ST251之间的2202个核心基因，其中78个蛋白质位于外膜或细胞外蛋白质中。我们的研究代表了物种分布的第一批基因组研究之一，遗传景观，以及越南患病cat鱼和人类感染中的气单胞菌流行病学。抗菌素耐药性和毒力强的达克曲霉菌株的出现强调了加强基因组监测和加强疫苗研究和开发以预防cat鱼和人类的气单胞菌病的需求，寻找潜在的疫苗候选物可以集中在膜和分泌蛋白编码的气单胞菌核心基因上。
