First identification and pathogenicity study of Vibrio harveyi isolated from diseased American eel ( Anguilla rostrata ) cultivated in freshwater

Abstract

Vibrio harveyi is ubiquitous in warm seawater and sediments and has become a common bacterial pathogen isolated from aquatic animals and even humans (Brehm et al., 2020;Joana et al., 2019;Peeralil et al., 2020). It is also a member of intestinal microflora in the intestines of marine vertebrates and invertebrates (Rungrassamee et al., 2016). Vibrio harveyi mainly infects shrimp (Martin et al., 2004;Zhou et al., 2012) and causes intestinal tract (Rungrassamee et al., 2016) and hepatopancreatic necrosis (Sarmila et al., 2019). Under natural conditions, fish are generally more susceptible to V. harveyi than invertebrates (Owens & Busico-Salcedo, 2006). Vibrio harveyi generally infect commercially important fish such as orange-spotted grouper (Epinephelus coioides) (Bai et al., 2020) and Atlantic salmon (Salmo salar) (Zhang & Austin, 2000). It also causes muscular ulcer, tail erosion, eye infection, symptoms of tongue sole (Cynoglossus semilaevis) and gilthead bream (Sparus aurata) (Haldar et al., 2010;Li et al., 2019), and 'Scale Drop and Muscle Necrosis disease' (SDMND)

Comparative phenotype and transcriptome analysis revealed the role of ferric uptake regulator (Fur) in the virulence of Vibrio harveyi isolated from diseased American eel (Anguilla rostrata)

“…The V. harveyi wild‐type strain HA_1, originally isolated from American eels ( Anguilla rostrota ) (Wan et al., 2022), was used as for constructing the mutant strain of HA_1‐Δ fur . The bacterial strains and plasmids used in this study are listed in Table 1.…”

“…The Gram‐negative bacterium Vibrio harveyi , known for its virulence, is recognized as a serious bacterial pathogen in aquaculture (Triga et al., 2023; Yang et al., 2021; Zhang et al., 2020). It causes severe liver and kidney diseases in aquatic animals (Wan et al., 2022). The V. harveyi can be cultured on TSA medium to form round yellow colonies, it is primarily identified using a series of biochemical tests, such as Biolog and API‐20E, and further confirmation is often verified through multi‐locus sequence analysis (Montanchez & Kaberdin, 2020).…”

“…These biochemical tests examine common features associated with the genus of Vibrio , such as the ability of V. harveyi to grow on different monosaccharides and polysaccharides (e.g. mannose, maltose, glucose), alcohols (mannitol and sorbitol) and tolerate high salinity environments (Wan et al., 2022). Currently, The NCBI Genome Database (https://www.ncbi.nlm.nih.gov/labs/data-hub/genome/?taxon=669) has recorded 117 genome sequencing projects of V. harveyi .…”

“…Additionally, the occurrence of various infectious diseases continues to challenge the healthy cultivation of farming eels (Guo et al., 2020; He et al., 2020; Xu et al., 2024). In our previous study, more and more strains of V. harveyi have been isolated from diseased American eels in different aquaculture farms (Wan et al., 2022). In this study, our aim was to investigate the phenotypic and genotypic differences of V. harveyi after the fur gene knockout.…”

A gene knockout mutant of ferric uptake regulator (Fur) reveals biofilm formation, energy metabolism and transcript regulation are three toxicity regulation strategies of Vibrio harveyi isolated from American eels (Anguilla rostrota)

“…The V. harveyi can be cultured on TSA medium to form round yellow colonies, it is primarily identi ed using a series of biochemical tests, such as Biolog and API-20E, and further con rmation is often veri ed through multilocus sequence analysis (Montanchez & Kaberdin, 2020). These biochemical tests examine common features associated with the genus of Vibrio, such as the ability of V. harveyi strains to grow on different monosaccharides and polysaccharides (e. g. mannose, maltose, and glucose), alcohols (mannitol and sorbitol), and tolerate high salinity environments (Wan et al, 2022). Currently, The NCBI Genome Database has recorded genome sequencing projects of 117 V. harveyi isolates (https://www.ncbi.nlm.nih.gov/labs/data-hub/genome/?…”