Genomic Epidemiology of Infantis in Ecuador: From Poultry Farms to Human Infections.

is one of the most important foodborne pathogens around the world. In the last years, . serovar Infantis has become an important emerging pathogen in many countries, often as multidrug resistant clones. To understand the importance of in the broiler industry in Ecuador, we performed a study based on phenotypic and WGS data of isolates from poultry farms, chicken carcasses and humans. We showed a high prevalence of in poultry farms (41.4%) and chicken carcasses (55.5%), but a low prevalence (1.98%) in human samples. . Infantis was shown to be the most prevalent serovar with a 98.2, 97.8, and 50% in farms, foods, and humans, respectively, presenting multidrug resistant patterns. All sequenced . Infantis isolates belonged to ST32. For the first time, a pESI-related megaplasmid was identified in Ecuadorian samples. This plasmid contains genes of antimicrobial resistance, virulence factors, and environmental stress tolerance. Genomic analysis showed a low divergence of . Infantis strains in the three analyzed components. The results from this study provide important information about genetic elements that may help understand the molecular epidemiology of . Infantis in Ecuador.