Abstract
Aeromonas veronii is a gram-negative species abundant in aquatic environments that causes disease in humans as well as terrestrial and aquatic animals. In the current study, 41 publicly available A. veronii genomes were compared to investigate distribution of putative virulence genes, global dissemination of pathotypes, and potential mechanisms of virulence. The complete genome of A. veronii strain ML09-123 from an outbreak of motile aeromonas septicemia in farm-raised catfish in the southeastern United States was included. Dissemination of A. veronii strain types was discovered in dispersed geographical locations. Isolate ML09-123 is highly similar to Chinese isolate TH0426, suggesting the two strains have a common origin and may represent a pathotype impacting aquaculture in both countries. Virulence of strain ML09-123 in catfish in a dose-dependent manner was confirmed experimentally. Subsystem category disposition showed the majority of genomes exhibit similar distribution of genomic elements. The type I secretion system (T1SS), type II secretion system (T2SS), type 4 pilus (T4P), and flagellum core elements are conserved in all A. veronii genomes, whereas the type III secretion system (T3SS), type V secretion system (T5SS), type VI secretion system (T6SS), and tight adherence (TAD) system demonstrate variable dispersal. Distribution of mobile elements is dependent on host and geographic origin, suggesting this species has undergone considerable genetic exchange. The data presented here lends insight into the genomic variation of A. veronii and identifies a pathotype impacting aquaculture globally.
Highlights
Aeromonas veronii is a Gram-negative, rod-shaped, mesophilic, motile bacterium in the Aeromonadaceae family
We sequenced the genome of A. veronii strain ML09-123 from diseased catfish in the U.S aquaculture industry
Comparative genomics analysis suggests that ML09123 and Chinese isolate TH0426 have a common origin
Summary
Aeromonas veronii is a Gram-negative, rod-shaped, mesophilic, motile bacterium in the Aeromonadaceae family. Clinical signs in fish often include, but are not limited to, skin ulcers and systemic hemorrhagic septicemia [9, 10] It is a digestive tract symbiont in zebrafish and leeches [11,12,13]. A clonal pathotype of A. hydrophila is associated with significant economic losses in the Chinese cyprinid fish industry [14]. We report the genome sequence of A. veronii strain ML09-123 isolated from diseased channel catfish in a commercial aquaculture pond in the southeast U.S, and we identified that it shares high identity with an isolate from Chinese aquaculture. Comparative virulence of A. hydrophila ML09-119 [21] and A. veronii ML09-123 in catfish confirmed that this clonal A. veronii pathotype has potential to cause disease in aquaculture. This work provides novel insights into the pathogenicity and epidemic potential of A. veronii in fish as well as genome variability within the species
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
