A genomic dissection of travel associated ESBL producing Salmonella Typhi originating from the Philippines - A one-off occurrence or threat to the effective treatment of typhoid?

ESBL producing Typhi has only been confirmed in a few cases. We surveyed the global occurrence and identified one new case. This resembled epidemiological a previously published strain why the two were compared by whole genome sequencing. Both isolates were acquired in the Philippines in 2007. They shared the same susceptibility profile, contained the same antimicrobial resistance genes; blaSHV-12, blaTEM-1, aac(6')IIc, strA, strB, tetD, and dfrA18, belonged to MLST ST1, haplotype H13, no chromosomal or plasmid SNP differences, and contained the incHI2/HI2A of 280 kb. Minor differences were observed in pulsotypes and one isolate contained a 144kb deletion of the SPI-7. These isolates likely belong to an undetected outbreak. The question is if this is a one-off occurrence or a threat to the future effective treatment of typhoid fever with severe public health implications – we call for a survey to search for persistence.