ABSTRACT: Salmonella enterica serovar 1,4,[5],12:i:- (S.1,4,[5],12:i:-), a monophasic variant of Salmonella typhimurium (S. typhimurium), is an emerging multidrug-resistant pathogen posing a significant threat to pediatric health. Research on this variant remains limited, and due to challenges associated with traditional identification methods, S.1,4,[5],12:i:- has often been misclassified as S. typhimurium. This study collected clinical data from 122 children infected with S.1,4,[5],12:i:- and 42 with traditional S. typhimurium in Fujian Province, China, between 2014 and 2023. Whole-genome sequencing was used for strain analysis. Our findings revealed that 77.87% of children with S.1,4,[5],12:i:- infection were aged between 1 month and
