PREVALENCE OF ANTIBIOTIC RESISTANT V. parahaemolyticus AND V. cholerae IN FISH AND HUMANS WITH SPECIAL REFERENCE TO VIRULOTYPING AND GENOTYPING OF V. parahaemolyticus

Abstract

This study aimed to investigate prevalence, virulence determinants, antibiogram and genotyping of Vibrio isolates from retail shrimp and tilapia fish as well as stool samples from gastroenteritis patients in Sharkia Governorate, Egypt. Vibrio spp were molecularly confirmed in 25.5% and 3% of fish and human stool samples, respectively. V. parahaemolyticus was isolated from 8.9%, 5% and 3% of shrimp, tilapia and stool samples, respectively. However, 0.7% of shrimp and 1.7% of tilapia were found to harbor V. cholera. trh and tdh virulence related genes were assessed in 34 V. parahaemolyticus isolates (25 from shrimp, 6 from tilapia and 3 from human stool). The tdh gene alone was recorded in 4 (16%) isolates from shrimp and 2 (66.7%) isolates from human stool. However, trh gene was detected alone in one (4%) isolate from shrimp. Moreover, both genes were detected simultaneously in one shrimp (4%) and one human stool (33.3%). Tilapia fish isolates were negative for both virulence genes. The resistance of the examined isolates were 100% (each of nalidixic acid and erythromycin), 81.6% (sulphamethoxazol), 73.7% (chloramphenicol), However, susceptibilities to gentamicin (81.6%), ciprofloxacin (73.7%) and 71.1% for each ampicillin/sulbactam and amikacin were observed. Multiple drug resistance was recorded in V. parahaemolyticus and V. cholerae isolates. Out of 38 isolates, 6 (15.8%) were resistant to all 14 antibiotics with MAR index of 1. Twenty of the isolates (52.6%) were resistant to 5-13 drugs with MAR index higher than 0.286. ERIC-PCR fingerprinting revealed five distinct profiles namely E1-E5 and the discriminatory index of the reaction was 0.5107, indicating low discrimination of the technique. In conclusion, this study revealed the contamination of tilapia and shrimp in fish markets with potentially virulent V. parahaemolyticus strains in the study area. Moreover, the presence of human and fish isolates in the cluster indicated the potential of the environmental isolates to cause human infection.

Keywords

• Vibrio spp.
• prevalence
• antimicrobial resistance
• genotyping
• ERIC-PCR