Co-infection of multidrug-resistant Aeromonas hydrophila and A. veronii in pangas (Pangasianodon hypophthalmus) reared in cage culture units of Sarodha Reservoir, Kawardha, Chhattisgarh, India– An outbreak report

During the winter season in January 2022, an outbreak of a disease with moderate mortality was reported in pangas fingerlings (Pangasianodon hypophthalmus) that were farmed in cages at Kawardha, Chhattisgarh, India.Morbid pangas had reddish skin and dropsy, which are typical lesions associated with motile aeromonad septicaemia (MAS).Upon initial screening with an Aeromonas-isolation medium, two multidrug-resistant Aeromonas strains were found to have infected the pangas.Later, the isolates were subjected to phenotypic characterization and antibiotic sensitivity tests followed by molecular characterization.The universal 16S rRNA gene analyses revealed the isolates Aeromonas hydrophila and A. veronii with up to 99% homology.The antibiogram revealed the sensitivity where A. hydrophila and A. veronii were resistant to six and seven antibiotics out of eleven tested antibiotics, respectively.Moreover, the present study also highlights an association between outbreaks of virulent pathogens and poor water quality.The reported mortality hints towards the co-infection of two common pathogens from the aquatic environment.However, further investigation is warranted to understand the pathogenesis.