Pan-genome analysis of Aeromonas hydrophila, Aeromonas veronii and Aeromonas caviae indicates phylogenomic diversity and greater pathogenic potential for Aeromonas hydrophila

Abstract

Aeromonas species are important pathogens of fishes and aquatic animals capable of infecting humans and other animals via food. Due to the paucity of pan-genomic studies on aeromonads, the present study was undertaken to analyse the pan-genome of three clinically important Aeromonas species (A. hydrophila, A. veronii, A. caviae). Results of pan-genome analysis revealed an open pan-genome for all three species with pan-genome sizes of 9181, 7214 and 6884 genes for A. hydrophila, A. veronii and A. caviae, respectively. Core-genome: pan-genome ratio (RCP) indicated greater genomic diversity for A. hydrophila and interestingly RCP emerged as an effective indicator to gauge genomic diversity which could possibly be extended to other organisms too. Phylogenomic network analysis highlighted the influence of homologous recombination and lateral gene transfer in the evolution of Aeromonas spp. Prediction of virulence factors indicated no significant difference among the three species though analysis of pathogenic potential and acquired antimicrobial resistance genes revealed greater hazards from A. hydrophila. In conclusion, the present study highlighted the usefulness of whole genome analyses to infer evolutionary cues for Aeromonas species which indicated considerable phylogenomic diversity for A. hydrophila and hitherto unknown genomic evidence for pathogenic potential of A. hydrophila compared to A. veronii and A. caviae.

Antibacterial potential of phytochemicals alone or in combination with antimicrobials against fish pathogenic bacteria

“…Aeromonas hydrophila is an important bacterial cause of cutaneous ulcerations and haemorrhagic septicaemia in several species of freshwater fish (Ghatak et al 2016). It is a natural inhabitant of organic matter at the bottom of the aquaculture tanks and in the intestinal tract of fish and may cause secondary or even primary infections, depending on the virulence of the strain and the host immune response (Ghatak et al 2016). Aeromonas veronii is a highly pathogenic species to fish, presenting several virulence factors (Sun et al 2016).…”

Purinergic signalling displays an anti‐inflammatory profile in the spleen of fish experimentally infected with Aeromonas caviae: Modulation of the immune response

“…Aeromonas caviae is a mesophilic bacterium belonging to the genus Aeromonas , which is ubiquitous in aquatic environments (Lim, Ee, Yin, & Chan, ), including urban drinking water (Carvalho, Martínez‐Murcia, Esteves, Correia, & Saavedra, ) and aquaculture (Lehane & Rawlin, ). Aeromonas caviae can infect a vast number of hosts, including humans and fishes (Ghatak et al., ). In fishes, this infection is characterized by hepatosplenomegaly, eye disease and ulcerative lesions on the body surface.…”

Aeromonas veronii caused disease and pathological changes in Asian swamp eel Monopterus albus

“…A. veronii is an opportunistic bacterium (Gholamhosseini et al, ; Mohammed & Peatman, ). It is an important pathogen of aquatic organisms and can cause septicaemia in fish, animals and humans (Dong et al, ; Ghatak et al, ).…”