[Assessment of new restriction enzymes: SfaAI and SmiI for the differentiation of Y enterocolitica bioserotype 4/O3 and 1B/O8 clinical isolates by pulsed-field gel electrophoresis (PFGE)].

Endonucleases SfaAI and SmiI have not been yet applied for Y enterocolitica genotyping. Our goal was to evaluate usefulness of these endonucleases and two other rarely used (SfiI and SmaI) ones for the differentiation of Y enterocoilitica clinical isolates by PFGE. Reference strains used in this study belong to the major agents of human yersiniosis in Poland, the bioserotype 4/O3 (n=5), and to the highly pathogenic bioserotype 1B/08 (n=5) that has recently emerged in Poland. Our data indicated that all the tested enzymes are useful for distinguishing Y enterocolitica strains of bioserotypes 4/O3 and 1B/O8 which are the most common representatives of the two Y enterocolitica subspecies: palearctica and enterocolitica, respectively. Hovewer, only two enzymes: SfaAI and SfiI completely differentiated strains belonging to the same bioserotype. The discrimination power of these two enzymes varied depending on the bioserotype. SfaAI and SfiI were found to be the most discriminatory for Y enterocolitica 1B/O8 and 4/O3, respectively. In conclusion, SfaAI and SfiI appear to be useful for the PFGE-subtyping of Y enetrocolitica isolates to aid epidemiological investigations of food-poisoning or dispersed-outbreaks.