BACTERIAL INFECTIONS IN SOME RED SEA FISHES

Mahmoud Mostafa Mahmoud ,Mohie Haridy ,Fatma Abd El-Moghny Salem ,Essam Ali Nour El-Deen ,Ebtsam Sayed Hassan ,Mahmoud Rahman Mohamed

doi:10.21608/avmj.2017.170963

Abstract

The present study was carried out to investigate the common bacterial infections of some saltwater fishes in Red Sea at Hurghada, Egypt. One hundred and twenty fishes of different species including Hipposcarus harid, Scarus ferrugineus and Scarus niger were subjected to bacteriological investigations.The bacteria isolated from the vital organs were phenotypically identified as Vibrio logei, V. ichthyoenteri, V. fischeri, Moritella marina, Photobacterium damselae subsp. piscicida and Edwardsiella tarda, in addition to two isolates of the genus Streptococcus. Experimental challenge with the dominant isolate, V. logei, proved its pathogenicity to H. harid with 86.7% mortality rate. Histopathological investigations of experimentally infected fish disclosed prominent pathological alterations in vital organs including liver and kidney. The antibiotic sensitivity of V. logei, revealed its sensitivity to Norfloxacin, Ciprofloxacin and Ofloxacin.

Highlights

Fisheries in the Red Sea are of considerable socio-economic importance to the Red Sea countries in terms of national food security and source of income for rural communities
Bacterial diseases represent the most influential category of disease problems that has a massive impact on fish health and production (Austin and Austin, 2016)
Vibrios are present everywhere in marine environment, but clinical disease outbreaks only occur when stressed fish are exposed to the pathogenic infectious agent

Summary

INTRODUCTION

Fisheries in the Red Sea are of considerable socio-economic importance to the Red Sea countries in terms of national food security and source of income for rural communities. In Egypt, the Red Sea has a major importance as a natural resource of fish (Sanders and Morgan, 1989; Azab et al, 1998). The marine environment encompasses a wide variety of biological, chemical and physical parameters, which if altered beyond acceptable limits, such as any stress inducer, may modulate the fish immunity leading to disease outbreaks (Roberts, 2012). Vibrios are present everywhere in marine environment, but clinical disease outbreaks only occur when stressed fish are exposed to the pathogenic infectious agent. The objectives of current study were to investigate bacterial infections of some Red Sea fishes at the area of Hurghada, Egypt; to examine the pathogenicity of the dominant bacterial isolate; to study the histopathological alterations induced by the pathogen and to determine the most effective antibiotic(s) against the dominant isolate

MATERIALS AND METHODS

RESULTS

DISCUSSION