Impact of site release vaginal pH buffer cream on introital colonization by gram-negative bacilli

Colonization of the vaginal introitus by gram-negative bacilli is a critical event in the pathogenesis of bacteriuria and is promoted by an abnormal pH elevation. To determine whether a pH reduction might inhibit colonization we conducted a placebo controlled, crossover study of a site release vaginal pH buffer cream. A total of 12 premenopausal women with a history of urinary tract infection participated in the 12-week investigation. The mean introital pH during application of the placebo and buffer was 4.87 and 4.61, respectively (p less than 0.01). However, the percentage of positive introital cultures during application of the placebo and buffer (40.3 and 35.3, respectively) and the mean density of colonization (23,600 and 22,700 bacteria per ml., respectively) were not significantly different. The percentage of positive introital cultures and the mean colonization density were also not different during application of the placebo and buffer when the patients were retrospectively stratified as light and heavy colonizers. These data suggest that alteration of the introital pH within a range of 4.5 to 5.0 does not influence the growth of uropathogens on the vaginal mucosa.