Sero-type of Group B Streptococci Isolated in Japan in Recent Years

In recent years there have been reported many cases of group B streptococcal infection in the newborns.In this report the authors conducted sero-typing of the total of 217 strains of group B streptococci isolated from clinical cases in various parts of Japan during the period of 1976-1978 and from healthy school children during the period of 1973-1975. The following results were obtained.1. Among 80 cases of clinical cases, who had been well documented, the 34 strains were isolated from cerebrospinal fluid and/or blood of the neonatal patients suffering frommeningitis and/or sepsis.The 11 s trains were from the newborns, who were small for date or of amniotic infection syndrome, including the newborns without a clinical sign. And 9 strains were from vaginal cultures of the mothers of the newborns suffering from meningitis and/cr sepsis.2. The most prevalent types were type III (31.3%), type III-R (25.0%) and type Ia (22.5%).3. Of 32 cases with meningitis and/or sepsis, 15 cases were of so-called early onset type and 17 cases were of late onset type according to the criteria by Baker.The most prevalent sero-types for both were type III and type III-R, and there was obsered no difference between two Baker's types in the distribution of serotypes. This is a little different situation from the reports of other countries on the distributior of sero-types among the patients of early onset and late onset type.4. The positive rate of group B streptococci among healthy primary school children was 1.1 on the average and the most prevalent types were type Ia (29.1%), type III (27.2%) and type Ic (27.2%), showing a little difference from the results on the clinical cases of neonatal infection by group B streptococci in the above.