Environmental parameters influence on the dynamics of total and pathogenic Vibrio parahaemolyticus densities in Crassostrea virginica harvested from Mexico’s Gulf coast

•V. parahaemolyticus densities in oysters were isolated in spring and winter seasons.•Pathogenic genes abundances varied with environmental parameters seasonal changes.•Water temperature modulated V. parahaemolyticus abundance during reduced salinities.•V. parahaemolyticus with potentially pathogenic genes raises important health issues. The influence of environmental parameters on the total and pathogenic Vibrio parahaemolyticus seasonal densities in American oysters (Crassostrea virginica) was evaluated for 1year. Harvesting site A yielded the highest mean densities of V. parahaemolyticus tlh+, tdh+/trh−, tdh−/trh+ and tdh+/trh+ during spring season at 2.57, 1.74, 0.36, and −0.40 log10MPN/g, respectively, and tdh+/orf8+ during winter season (0.90 log10MPN/g). V. parahaemolyticus tlh+ densities were associated to salinity (R2=0.372, P