Isolation, molecular characterization, and antibiotic resistance patterns of Vibrio parahaemolyticus isolated from coastal water in the Eastern Province of Saudi Arabia

Vibrio parahaemolyticus is a Gram-negative halophilic marine microbe that causes gastroenteritis, wound infections, and septicemia in humans. Since the emergence of the pandemic clone O3:K6, V. parahaemolyticus has become a globally well-known pathogen. In this study, 375 seawater samples collected from the Eastern coast of Saudi Arabia were tested for the presence of V. parahaemolyticus. Three hundred and forty samples were determined positive for V. parahaemolyticus using traditional microbiological techniques. The genes toxR and tlh were detected via polymerase chain reaction (PCR) in 41 isolates from 23 samples (6%). Thermostable direct hemolysin (tdh) and thermostable direct hemolysin-related hemolysin (tdh) are the most common virulence genes associated with V. parahaemolyticus. As such, four isolates were tdh+ (1%) and another four were trh+ (1%). No evidence of pandemic clones was detected using group-specific PCR (GS-PCR). Samples were tested for antibiotic susceptibility against 28 agents. The vast majority of samples exhibited high resistance to carbenicillin (98%), ampicillin (88%), and cephalothin (76%). The multiple antibiotics resistance index was >0.2 for 35% of the isolates. The results of this study confirm the presence of V. parahaemolyticus in the Eastern coast of Saudi Arabia. This is the first report of tdh+ and trh+ isolates from this area.