Group B Streptococcus infection (GBS, Streptococcus agalactiae) is asignificant cause of perinatal morta¬lity and morbidity. Thus all pregnant women (withthe exception of those with a positive urine culture for GBS at any time during pregnancy) should undergo screening for streptococcus colonizationat 35 to 37 weeks of gestation with a vaginal culture from the lower third of the vagína, lf the vaginal culture is positi¬ve, we do not treat the patient antepartum, but perform intrapartum prophylaxis (when membranes are rup-tured or at the onset of uterine contractions) with the administration of intravenous antibiotics. Penicillin antibiotics are the first choice of treatment. If the patient is penicillin-allergic with a low risk of anaphylaxis, we administer cephalosporins. If there is a high risk of anaphylaxis, we administer a lincosamide- clindamycin or a macrolide- erythromycin. It is most beneficial to administer the antibiotics more than 4 hours before delivery, otherwise the risk of colo-nization of the neonate dramatically increases. At delivery, the pediatrician must always be informed of maternal colonization.

        Key words: group B Streptococcus - Streptococcus agalactiae- screening - vaginal colonization - neonatal colonization - GBS infection - GBS sepsis.