Prevalence and antimicrobial resistance of Vibrio spp. in the shrimp retail trade in Northwest Mexico

Northwest Mexico represents one of the leading production regions for white shrimp (Litopenaeus vannamei), making it an important activity for the regional economy and national food security. Although much of the shrimp is exported, it is also sold in local markets. In these markets, there are often problems with how the shrimp is handled and stored, causing harmful bacteria, like Vibrio parahaemolyticus , Vibrio cholerae , and Vibrio alginolyticus , to grow quickly. Bacterial antimicrobial resistance ( AMR ) is a serious problem in Mexico and worldwide. It affects public health, aquaculture production, and food safety. Ninety-four different types of Vibrio bacteria were tested against 16 different antibiotics. V. parahaemolyticus was highly resistant to chloramphenicol (81.25%) and tetracycline (56.25%), while V. cholerae was resistant to sulfamethoxazole-trimethoprim and ampicillin (76.47%). V. alginolyticus showed lower levels of resistance. In addition, genes that cause disease, such as pirA/B, tdh, trh, and VpadF , which are linked to intensive aquaculture in northwestern Mexico, and genes that resist antibiotics, such as qnrVC457, strA, blaCARB , cat , and tetA , were identified, especially in V. cholerae and V. parahaemolyticus . These findings show that we must take more decisive action to control and monitor antimicrobial use. • Shrimp-associated Vibrio spp. exhibited high levels of antimicrobial resistance linked to aquaculture environments. • Vibrio parahaemolyticus showed elevated resistance to chloramphenicol, while remaining susceptible to florfenicol and fosfomycin. • Vibrio cholerae displayed resistance to clinically relevant antibiotics, including ampicillin and erythromycin. • Key virulence genes (tdh, trh, ctxA) were detected, indicating pathogenic potential in human infections. • The combination of drug resistance and pathogenic potential in shrimp-associated Vibrio spp strains indicates the necessity for ongoing surveillance programs in retail trade