[Group B streptococci: serotyping data and susceptibility to antibiotics (author's transl)].

A study of the prevalence of group B streptococci in women (covering 6,000 samples) shows the vaginal presence to be comprised between 6.34 and 16.8%. The highest rate is found in a Centre for venereal diseases. The use of selective media results in a 50 to 75% increase in the number of germ-carries. The distribution found after serotyping of 1,469 strains has been studied. Over half of the strains isolated from the vagina and from infants belong to serotype II and III, one third of the strains causing serious infections are of type III; however, there is a wide dispersion of the serotypes found in neonatal infections. The test for pigmentation on Columbia medium offers an excellent approach for the diagnosis of group B streptococci. MIC testing of 7 antibiotics for 782 strains of various serotypes demonstrates high susceptibility to the beta-lactam antibiotics and makes it possible to detect rare strains with features of polyresistance to chloramphenicol and some macrolide antibiotics.