Bacterial diseases are among the most important and common problems faced by aquaculturist worldwide. Identification and treatment of causative agent based on gross sign are sometimes not very effective because several isolates of the pathogens are associated with other aquatic vertebrate diseases. In this study, bacterial isolates were isolated from two different places, FRD Godawari and FRC Pokhara and diagnosed by obtaining pure culture followed by phenotypic test (morphological, physiological and biochemical test) and compared with existing diagnostic scheme. Based on certain uniformity such as Gram-negative and positive reactions for catalase, oxidase and fermentative reaction on glucose enables to identify the isolates, Aeromonas hydrophila. Some sugar utilization and decarboxylase test showed differences in strains of Aeromonas hydrophila.

Bacterial diseases are among the most important and common problems faced by aquaculturist worldwide. Identification and treatment of causative agent based on gross sign are sometimes not very effective because several isolates of the pathogens are associated with other aquatic vertebrate diseases. In this study, bacterial isolates were isolated from two different places, FRD Godawari and FRC Pokhara and diagnosed by obtaining pure culture followed by phenotypic test (morphological, physiological and biochemical test) and compared with existing diagnostic scheme. Based on certain uniformity such as Gram-negative and positive reactions for catalase, oxidase and fermentative reaction on glucose enables to identify the isolates, Aeromonas hydrophila. Some sugar utilization and decarboxylase test showed differences in strains of Aeromonas hydrophila.