The multilocus sequence typing scheme used previously for phylogenetic analysis of Escherichia coli was applied to 107 clinical isolates of Shigella flexneri. DNA sequencing of 3423 bp throughout seven housekeeping genes identified eight new allele types and ten new sequence types among the isolates. S. flexneri serotypes 1–5, X and Y were clustered together in a group containing many allelic variants while serotype 6 formed a distinct group, as previously established.
EIEC, enteroinvasive E. coliMLST, multilocus sequence typingST, sequence type
The GenBank/EMBL/DDBJ accession numbers for the nucleotide sequences of the new allele types identified in this study are EF364101–EF364108 (icd123, EF364101; adk116, EF364102; fumC149, EF364103; fumC145, EF364104; purA98, EF364105; purA96, EF364106; purA97, EF364107; purA95, EF364108).
A full list of clinical S. flexneri isolates subjected to MLST analysis in this study and a phylogenetic tree generated by the neighbour-joining method for S. flexneri are available as supplementary material with the online version of this paper.