Serodiversity, antibiotic resistance, and virulence genes of Vibrio parahaemolyticus in oysters collected in coastal areas of northwestern Mexico between 2012 and 2020

• Published in: Food microbiology 2024-10, Vol.123, p.104567, Article 104567
• Main Authors: Flores-Villaseñor, Hector, Velázquez-Román, Jorge, León-Sicairos, Nidia, Angulo-Zamudio, Uriel A., Lira-Morales, Carolina, Martínez-García, Jesús J., Acosta-Smith, Erika, Valdés-Flores, Jorge, Tapia-Pastrana, Gabriela, Canizalez-Román, Adrian
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Drug Resistance, Bacterial; Mexico - epidemiology; Microbial Sensitivity Tests; Ostreidae - microbiology; Oyster; Pathogenic; Serogroup; Serotypes; Shellfish - microbiology; Vibrio parahaemolyticus; Vibrio parahaemolyticus - drug effects; Vibrio parahaemolyticus - genetics; Vibrio parahaemolyticus - isolation & purification; Virulence - genetics; Virulence Factors - genetics
• ISSN: 0740-0020; 1095-9998; 1095-9998
• DOI: 10.1016/j.fm.2024.104567

This study aimed to determine the prevalence of V. parahaemolyticus in oysters from the northwestern coast of Mexico and to identify the serotypes, virulence factors, and antibiotic resistance of the strains. Oyster samples were collected from 2012 to 2020 from the northwest coast of Mexico; biochemical and molecular methods were used to identify V. parahaemolyticus from oysters; antiserum reaction to determine V. parahaemolyticus serotypes, and PCR assays were performed to identify pathogenic (tdh and/or trh) or pandemic (toxRS/new, and/or orf8) strains and antibiotic resistance testing. A total of 441 oyster samples were collected and tested for V. parahaemolyticus. Forty-seven percent of oyster samples were positive for V. parahaemolyticus. Ten different O serogroups and 72 serovars were identified, predominantly serotype O1:KUT with 22.2% and OUT:KUT with 17.3%. Twenty new serotypes that had not been previously reported in our region were identified. We detected 4.3% of pathogenic clones but no pandemic strains. About 73.5% of strains were resistant to at least one antibiotic, mainly ampicillin and ciprofloxacin; 25% were multi-drug resistant. In conclusion, the pathogenic strains in oysters and antibiotic resistance are of public health concern, as the potential for outbreaks throughout northwestern Mexico is well established. •The prevalence of V. parahaemolyticus in oysters was 41.7%.•A high serodiversity of V. parahaemolyticus was found in oysters: ten different O-serogroups and 72 serovars.•4.3% of the V. parahaemolyticus strains isolated from oysters were pathogenic.•73.5% of V. parahaemolyticus strains were resistant to at least one antibiotic.