Title Genomic surveillance links livestock production with the emergence and spread of multi-drug resistant non-typhoidal Salmonella in Mexico
Author Enrique Jesús Delgado-Suárez1*, Rocío Ortíz-López2, Wondwossen A. Gebreyes3, Marc W. Allard4, Francisco Barona-Gómez5, and María Salud Rubio-Lozano1
Address 1Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico City, Mexico, 2Tecnológico de Monterrey, School of Medicine and Health Sciences, Monterrey, Mexico, 3College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA, 4Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U. S. Food and Drug Administration, College Park, Maryland, USA, 5Evolution of Metabolic Diversity Laboratory, Unidad de Genómica Avanzada (Langebio), Cinvestav-IPN, Irapuato, Guanajuato, Mexico
Bibliography Journal of Microbiology, 57(4),271–280, 2019,
DOI 10.1007/s12275-019-8421-3
Key Words antimicrobial resistance, Salmonella, genomics, beef production
Abstract Multi-drug resistant (MDR) non-typhoidal Salmonella (NTS) is increasingly common worldwide. While food animals are thought to contribute to the growing antimicrobial resistance (AMR) problem, limited data is documenting this relationship, especially in low and middle-income countries (LMIC). Herein, we aimed to assess the role of non-clinical NTS of bovine origin as reservoirs of AMR genes of human clinical significance. We evaluated the phenotypic and genotypic AMR profiles in a set of 44 bovine-associated NTS. For comparative purposes, we also included genotypic AMR data of additional isolates from Mexico (n = 1,067) that are publicly available. The most frequent AMR phenotypes in our isolates involved tetracycline (40/44), trimethoprim-sulfamethoxazole (26/44), chloramphenicol (19/44), ampicillin (18/44), streptomycin (16/44), and carbenicillin (13/44), while nearly 70% of the strains were MDR. These phenotypes were correlated with a widespread distribution of AMR genes (i.e. tetA, aadA, dfrA12, dfrA17, sul1, sul2, bla-TEM-1, blaCARB-2) against multiple antibiotic classes, with some of them contributed by plasmids and/or class-1 integrons. We observed different AMR genotypes for betalactams and tetracycline resistance, providing evidence of convergent evolution and adaptive AMR. The probability of MDR genotype occurrence was higher in meat-associated isolates than in those from other sources (odds ratio 11.2, 95% confidence interval 4.5–27.9, P < 0.0001). The study shows that beef cattle are a significant source of MDR NTS in Mexico, highlighting the role of animal production on the emergence and spread of MDR Salmonella in LMIC.