Isolation of Aeromonas sobria from an endemic fish, Phoxinellus pstrossii

Objective: The aim of this research was to identify potential bacterial disease of dead wild fish (Phoxinellus pstrossii) from river Trebisnjica in Bosnia and Herzegovina. Fishes were submitted with several other species in the laboratory after an outbreak in this river. Method & Materials: Isolation of bacteria from digestive tract of Phoxinellus pstrossii was obtained on Blood agar, MacConkey agar and Bromocresol Purple Lactose agar, at 25ºC for 24 h. Bacterial strain was preliminary identified using standard biochemical techniques such as oxidase, catalase, triple sugar iron agar, OF glucose, indol, urea, aesculin, citrates and motility tests. Final identification was performed with API 20E test. Tissue of dead fish was investigated by light microscopy. Tissue samples were fixed in 10% buffered formalin over 24 hours. Following fixation, tissue was routinely processed, embedded in paraffin and 4μm thick sections were prepared and stained with standard Hematoxilin-Eosin method. Results & Conclusion: Aeromonas sobria was isolated in pure culture from digestive tract of Phoxinellus pstrossii. Histopathologic examination of fish organs revealed diffuse hemorrhagic colitis in the caudal third of the colon and multifocal echimotic hemorrhages in the musculature. Observed histopathologic changes were correlated with Aeromonas sobria infection. This is first confirmation of occurrence of Aeromonas sobria in Bosnia and Herzegovina, and first report of Aeromonas sobria infection in Phoxinellus pstrossii.

کلیدواژه ها:

Aeromonas sobria ، fish ، Phoxinellus pstrossii ، isolation ، histopathology ، outbreak