Phylogenetic analysis of Salmonella enterica isolated from imported and local potato seed tubers

Human pathogens on plants are an emerging global health concern. Salmonella enterica exhibits a broad range of host associations, including plants, animals, and humans. Therefore, the rapid characterization of Salmonella on potatoes is essential for ensuring food safety, protecting crops, and preventing transmission to humans. The present study investigates the phylogenetic relationships of potato-borne S. enterica with clinical lineages. Among sixty-seven S. enterica isolates collected from local and imported potato seed varieties, 63 (94.02%) were confirmed to carry the invA gene, a specific marker for Salmonella. Random Amplified Polymorphic DNA (RAPD) analysis grouped these isolates into three distinct clusters, with Salmonella strains 7S-Moz-L and 1S-Kar-I showing genetic similarity to the clinical strain S. typhi 5S-CL2 (MZ708960). The invA protein is identified as a virulence factor relevant to human infections and may play a role in tuber colonization. Phylogenetic analysis of invA sequences revealed homology between Salmonella strain 9SF-Ast-L (MW319054), isolated from the Asterix potato variety, and the clinical strain S. typhi 5S-CL2. Moreover, Salmonella strain 1S-Kar-I [MW319050], isolated from the imported Karuda variety, showed an evolutionary relationship with Salmonella strains 7S-Moz-L (MW319052) and 8S-Qas-L (MW319053), both from local potato varieties. Overall, the study underscores the importance of identifying S. enterica in potato seeds prior to planting or transport to prevent the spread of quarantine pathogens and ensure public health safety.