Characterization of Vibrio parahaemolyticus Infection in Gilthead Seabream (Sparus auratus) Cultured in Egypt

Abstract

This study aimed to diagnose V. parahaemolyticus infection among cultured Gilthead Seabream from the Suez Canal area of Egypt. A total of 200 Gilthead Seabream fish samples were clinically examined for the presence of any abnormal external or internal clinical findings. Samples from internal organs of moribund fish were subjected to histopathological and microbiological examinations. Retrieved isolates were biochemically identified using API 20 E system then further confirmed by regular PCR. Antibiogram profiling of the retrieved isolates was also done. A sum of 64 V. parahaemolyticus isolates was retrieved from the examined moribund Gilthead seabream samples. A total of 18 (32.8%) of the retrieved isolates were positive for the Kanagawa phenomenon (KP+ve). An expected product with a length of 368 bp size bands was found from tested strains of toxR targeted gene. Further, the PCR amplification of pR72H target gene generated an expected product with a length of 387-bp. Most of the isolates showed resistance to Ampicillin (AMP 10μg) and Gentamycin (CN 10μg) with high sensitivity to Sulphamethoxazole/Trimethoprim (SXT 25μg). Pathologically, severe inflammatory reactions together with melanomacrophage center alterations were recorded within the examined splenic, hepatic, renal and branchial tissues. Ultimately, the current study emphasizes the critical fish health threats posed by V. parahaemolyticus with consequent impacts on human consumers. Thus, competent biosecurity strategies should be adopted to control Vibrio infection in marine fishes and to minimize the antimicrobial resistance hazards in mariculture.