Molecular epidemiological and genetic variability of <i>Salmonella</i> isolates from the tropical mountainous region of southern China (2017–2024)

<i>Salmonella</i> is a serious zoonotic foodborne pathogen and the third leading cause of death from human diarrheal diseases worldwide. In this study, we report, for the first time, a systematic surveillance of <i>Salmonella</i> prevalence among clinical patients, food, and environmental sources in the tropical mountainous regions of southern China from 2017 to 2024. Our findings illuminate the prevalence and genetic dynamics of <i>S. enterica</i> across diverse sources, as well as differences between patients with diarrheal disease and those with systemic infections characterized by bacteremia. Moreover, we observed high resistance to clinically important treatment drugs, including fluoroquinolones and third-generation cephalosporins, in these regions. These results provide critical evidence to inform more effective surveillance, treatment, and control strategies in tropical settings and underscore the need for continuous, real-time monitoring of pathogen dynamics.