Prevalence of Vibrio parahaemolyticus in seabass (Dicentrarchus Labrax) and seabream (Sparus aurata) and Detection of Streptomycin-resistant Strains

Abstract

Vibrio species are the most common and serious pathogens in fish and shellfish marine aquaculture worldwide. The present study aimed to determine the prevalence of Vibrio spp. in seabass and seabream in fish markets, especially streptomycin-resistant strains that have great public health importance. A total of 30 seabass (Dicentrarchus Labrax) and 30 seabream (Sparus aurata) were purchased from fish markets at Kafr El Sheikh Governorate and subjected to bacteriological examination. The PCR assay was used for the detection of virulence genes (tdh and trh), aminoglycoside resistance gene (aadA1), and toxR gene. The results indicated that the total prevalence of Vibrio spp. was 26.66%, including V. parahaemolyticus (8.3%), V. alginolyticus (8.3%), V. mimicus (3.3%), V. harveyi (5%) and V. vulnificus (1.6%). The toxR, trh, and aadA1 genes were found in all V. parahaemolyticus isolates while tdh gene was found in 80% of isolates. Antimicrobial sensitivity test of V. parahaemolyticus isolates showed sensitivity to ciprofloxacin, norfloxacin, cefotaxime, and chloramphenicol. Vibrio parahaemolyticus isolates were resistant to ampicillin, erythromycin, streptomycin, and gentamycin. The present results indicated that good hygienic measures should be taken to avoid infection with Vibrio species, especially V. parahaemolyticus that can pose a great risk to human health.