IS200 and multilocus sequence typing for the identification of Salmonella enterica serovar Typhi strains from...

In this work, IS200 and multi-locus sequence typing (MLST) were used to analyze 19 strains previously serotyped as Salmonella enterica serovar Typhi and isolated in Indonesia (16 strains), Mexico (2 strains), and Switzerland (1 strain). Most of the strains showed the most common Typhi sequence types, ST1 and ST2, and a new Typhi genotype (ST1856) was described. However, one isolate from Mexico and another from Indonesia were of the ST365 and ST426 sequence types, indicating that they belonged to serovars Weltevreden and Aberdeen, respectively. These results were supported by the amplification of IS200 fragments, which rapidly distinguish Typhi from other serovars. Our results demonstrate the utility of IS200 and MLST in the classification of Salmonella strains into serovars. These methods provide information on the clonal relatedness of strains isolated worldwide.