Evaluation of pulsed-field gel electrophoresis for typing of Shigella dysenteriae type 1

Pulsed-field gel electrophoresis (PFGE) has been used successfully to discr iminate between strains of many different bacterial species. In this study, digestion of bacterial DNA with the restriction endonuclease NorI and PFGE were evaluated for the typing of isolates of Shigella dysenteriae type 1, an important cause of epidemic dysentery. There were 27 isolates from four outbreaks of dysentery, and 44 isolates from endemic dysentery cases and a laboratory culture collection. The epidemic isolates yielded two types each with two subtypes, whereas the endemic isolates and culture collection yie lded eight types with numerous subtypes. These findings suggest that S, dys enteriae 1 can be typed by PFGE.