Association between lesional or non lesional S-aureus strains from patients with impetigo and exfoliative toxin production. No association with SmaI PFGE patterns

Contrasting data are reported in the literature on the percent positivity r ates (13.5%-100%) of exfoliative toxin (ET) production by S. aureus strains isolated from impetigo patients in Japan and in France. In the present study, by means of a recently available latex-test, toxin-A (ETA) or toxin-B (ETB) production was found in 67.6% of the 34 S. aureus st rains isolated from 19 lesional (63.2%) and 15 non-lesional (nose or pharyn x, 73.3%) areas of patients with impetigo (with no significant difference b etween the lesional and non-lesional isolates). ETA + ETB were produced by 44.1% of the strains, while 32.4% were non-producers. In contrast, the perc ent positivity rate observed in 40 [20 lesional and 20 non-lesional (nose o r pharynx)] strains isolated in patients with atopic dermatitis was 15.0% ( p<0.001 both for the lesional and non-lesional strains versus impetigo, wit h no significant difference between lesional and non lesional strains). Fin ally, 26 strains from other types of specimens (abscesses, hemocultures, ur ine, central venous catheters, bronchoalveolar lavages) showed an 11.5% pro duction rate of ETA or ETB (p<0.001 versus impetigo strains, no significanc e versus atopic dermatitis). These data point to a significant association between exfoliative toxin production and S. aureus strains isolated in impe tigo, both in lesional areas and in nasal/pharyngeal reservoirs. An attempt to correlate SmaI pulsed-field gel electrophoresis (PFGE) restriction patt erns and exfoliative toxin production showed no significant association in either group.