Genetic diversity of Shigella species from different intercontinental sources.

One hundred and twenty three strains of Shigella spp. (mostly Shigella sonnei and Shigella flexneri) were isolated between 1995 and 2000 from patients suffering from traveller's diarrhoea. Seventy nine of them have been typed by digestion of their chromosomal DNA with Xba I and pulsed field gel electrophoresis. Results show a high degree of heterogeneity in both S. sonnei and S. flexneri isolates. This is the first time that the molecular typing of such a high number of geographically unrelated isolates of Shigella sp. is carried out, showing a high level of genomic re-arrangement.