Vaginal colonization with Staphylococcus aureus, positive for toxic-shock marker protein, and Escherichia coli in healthy women.

The vaginal colonization of 495 healthy women with strains of Staphylococcus aureus positive for the toxic-shock marker protein (pyrogenic exotoxic C) was examined prospectively. Production of the marker protein was detected by analytic isoelectrofocusing of culture filtrates in polyacrylamide gels (isoelectric point, 7.2). Toxicogenic strains of S. aureus were isolated from 2.6% of the women and nontoxicogenic strains from 4.0%. Vaginal carriage of toxicogenic S. aureus was found to be significantly correlated only with coisolation of Escherichia coli when a number of factors were analyzed by multivariate logistic regression and compared with values among women carrying no vaginal S. aureus or only nontoxicogenic strains (odds ratios, 8.17 and 11.02, respectively; 95% confidence intervals, 2.27-29.31 and 1.42-85.31, respectively). These data may explain the higher rate of vaginal colonization with E. coli in addition to toxicogenic S. aureus among women with toxic-shock syndrome (64%) than among age-matched control women (12%; P less than .001).