Clinical and experimental study on vibriosis in ornamental fish

الملخص EN

The aim of this study was to investigate vibrio infections among some species of ornamental fishes in Assiut, Egypt.

A total number of 100 ornamental fishes showing signs of septicaemia were collected from private ornamental fish shops in Assiut Governorate.

Dropsy, exophthalmia, detachment scale, and haemorrhage on the body surface were the main clinical signs observed on the fish collected.

According to conventional identification, 59 isolates suspected to be vibrio species were recovered from 40 fish.

Cultural, morphological and biochemical characteristics of these isolates identified them as V.

vulnificus (38.98 %), V.parahaemolyticus (28.8), V.harveyi (11.86 %), Vibrio alginolyticus (5.08%), V.mimicus (5.08 %), V.

ordalii (6.78 %).

and V.

fisheri (3.39 %).

A molecular typing system based on amplification of the intergenic spacer (IGS) region was used to confirm the identity of a Vibrio vulnificus isolate to investigate its pathogenicity in fantail fish through an experimental challenge.

Vibrio cholerae is also molecularly identified and discussed but not isolated.

The prominent signs seen on experimentally infected fish included hemorrhages in the peritoneum and visceral organs.

The intestine were filled with bloody fluid, while gelatinous exudates were covering the gas bladder.

The V.

vulnificus strain used for experimental challenge was sensitive to Oxytetracyclin, Neomycin, and Erythromycin, but was resistant to Ampicillin and Tobramycin.