Multidrug Resistance, V16S rRNA Gene Sequencing, High Frequency of Toxins Encoding Genes (tox, tdh, trh) in Parahaemolyticus and Non -parahaemolyticus Vibrios Isolated from Shellfish

PCR amplification of V16S-rRNA, tox, tdh, trh was applied as a molecular typing approach to identify potentially toxigenic vibrio species. Thirty vibrio strains were isolated from several types of shellfish collected from Ismailia district, Egypt. Isolates were recognized by conventional biochemical features and PCR amplification then tested for their sensitivity against twelve antibiotics. Multiple sequences alignment of V16S-rRNA indicated the high incidence of V.parahaemolyticus (n= 6) V. cholerae (n=5) and V. fluvialis (n=5) among the investigated groups. V. harveyi (n=3), V. alginolyticus ( n=2 )V. vulnificus (n=1) and (n=8) vibrio sp were reported as well. Toxins encoding genes (tox, tdh, trh) shown high incidence frequency in the majority of the identified vibrio species. Identified isolates were reported as potential pathogenic and multiple antibiotic resistant with noticeably high resistant indexes ranged from (0.5-1). The results significantly emphasized that the isolates have been originated from potential risk sources of infection.