Isolation and Molecular Detection of Pathogenic Vibrio Species among Economic Fish from Red Sea in Egypt

Abstract

A total of 105 samples were collected from Siganus rivulatus, Mulloidichthys vanicolensis, and Lethrinus lentjan, freshly captured from the Red Sea along Hurghada City coastline zone, Egypt. Clinical and post mortem findings revealed the presence of characteristic clinical signs and lesions similar to those reported in vibriosis. Out of 43 putative Vibrio species isolates obtained by culturing; 30 isolates were presumptively discriminated into Vibrio cholera (n=11), Vibrio anguillarum (n=8), Vibrio fluvialis/ Vibrio furnissii (n=4), Vibrio harveyi (Vibrio carchariae) (n=4) and Vibrio alginolyticus (n=3), but it was not initially possible to approve or repudiate that the remaining 13 isolates were Vibrio species through phenotypic characterization. By using PCR, targeting Vibrio-specific 16S rRNA gene, the presumptive 30 Vibrio isolates and 9 out of the remaining 13 isolates were confirmed as Vibrio species. The prevalence of Vibrio species was 37.1% among the examined fish species; 47.1%, 34.3% and 30.6% in Mulloidichthys vanicolensis, Lethrinus lentjan and Siganus rivulatus, respectively. The occurrence of Vibrio species pathogenic for aquatic animals and humans was confirmed which possess public health concerns. Also, the utility of molecular technique to improve the identification of phenotypic Vibrio like species is recommended.