Streptococcal agalactiae Archives - Revista Brasileira de Ginecologia e Obstetrícia

PURPOSE: to evaluate the influence of vaginal environment of pregnant women on group B streptococcus (GBS) survival after 8, 24 e 48 h in Amies and Stuart transport media. METHODS: Three vaginal samples were collected from 30 pregnant women attending the Prenatal Care Outpatient Clinic of the Centro de Atenção Integral à Saúde da Mulher (CAISM), Universidade Estadual de Campinas (UNICAMP). The first sample was placed directly onto Todd-Hewitt selective medium; the second was used to perform a gram-stained microscopy, and the third swab was placed in 2 mL physiological saline to which 200 µL of a suspension with 1-2 x 10(8) colony-forming units of GBS was added. After homogenization, six swabs were collected from this suspension (3 from Amie medium and 3 from Stuart medium). These six swabs were kept at room temperature for 8, 24 and 48 h and then incubated on blood agar. Bacterial growth at 37ºC was observed after a 24-h incubation period and it was semiquantitatively graded (0-3+) according to the number of colonies. Statistical analysis was performed by the exact Fisher test and the level of significance was set at 0.05. RESULTS: the recovery of GBS after 48-h storage in Amie and Stuart media was 97 e 87%, respectively. In one of the four cases where no GBS recovery was possible after 48 h of storage, vaginal pH was higher than 4.5, and in two of those cases cytolytic vaginosis was found. CONCLUSIONS: both transport media showed to be appropriate for GBS recovery up to 48 h after sampling. Characteristics of the vaginal enviroment did not influence GBS recovery as observed in this study.