Isolation and characterization of bacteria associated with ulcerative disease fish, Clarias batrachus

Bacteriological examination of Clarias batrachus, suffering from ulcerative disease was carried out. As a whole, 18 species of bacteria viz., Aeromonas caviae, A.hydrophila, A.salmonicida, A.sobria, Bacillus sp., Escherichia coli, Edwardsiella tarda, Flavobacterium columnare, Flavobacterium sp., Micrococcus luteus, Plesiomonas shigelloides, Pseudomonas aeruginosa, Pseudomonas sp., Salmonella sp., Staphylococcus aureus, Staphylococcus epidermiidis, Streptococcus sp., and unidentified bacteria were isolated from the fishes having ulcerative disease. Out of 30 isolates, Aeromonas caviae accounted 3.4%, A.hydrophila 10%, A.salmonicida 3.4%, A.sorbia 3.4%, Bacillus sp. 10%, Escherichia coli 3.4%, Edwardsiella tarda 3.4%, Flavobacterium columnare 3.4%, Flavobacterium sp. 3.4%, Micrococcus luteus 3.4%, Plesiomonas shigelloides 3.4%, Pseudomonas aeruginosa 10%, Pseudomonas sp. 6.7%, Salmonella sp. 6.7%, Staphylococcus aureus 3.4%, Staphylococcus epidermidis 6.7%, Streptococcus sp. 6.7%, and unidentified bacteria 10%. Out of 18 species of bacteria, Aeromonas hydrophila, A.salmonicida, A.sobria, Edwardsiella tarda, Flavobacterium columnarae, Flavobacterium sp., Micrococcus luteus, Salmonella sp., Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus sp., were pathogenic while remaining bacterial species were non pathogenic.