Streptococcus group B serotype distribution in anovaginal isolates of women in term pregnancy

BACKGROUND: To evaluate Streptococcus group B (GBS) serotype distribution in anovaginal isolates of women in term pregnancy and to assess the correlation of the distribution with socio-epidemiological variables and neonatal outcomes. DESIGN: An observational study. SETTINGS: Department of Gynecology and Obstetrics, Specialist Teaching Hospital in Tychy, Poland. POPULATION: 80 women between 37 and 40 gestation weeks with preserved fetal membranes and who had not been treated with antibiotics for at least two weeks before the study. MATERIAL AND METHODS: The specimens from the vagina and the rectum of pregnant women were collected. GBS colonization tests were conducted in compliance with Centers for Disease Control and Prevention recommendations. Serotyping of the isolates was performed using the Essum GBS Serotyping Kit (Umea, Sweden) according to manufacturer's instruction. Mein outcome measures. GBS serotype distribution in the population of Polish women in term pregnancy. RESULTS: In the studied group of 80 pregnant women GBS colonization rate was 28.7%. Four GBS serotypes were observed (Ia, V, III and II). Serotype Ia was the most predominant -43.47%. For GBS Ia, V and III serotypes, no significant difference in the prevalence of diabetes mellitus and neonatal outcomes was observed. Only in one case early-onset sepsis was diagnosed in the neonate and serotype Ia was determined. CONCLUSIONS: 1) From among four identified GBS serotypes in the population of Polish pregnant women, serotype Ia was the most dominant. 2) For GBS serotypes, no significant difference in the prevalence of diabetes mellitus and neonatal outcomes was observed. 3) Active immunization aimed for preventing GBS colonization in mothers should include not only serotypes V, II and III but also Ia in order to be an effective and safe in preventing life threatening neonatal infections.