Serotype Determination of Streptococcus Agalactiae Detected from Vagina and Urine of Pregnant Women in Yazd, Iran-2015

Group B streptococcus (GBS), is a bacterium that colonize in the vagina and/or rectum of pregnant, as well as non-pregnant women. The frequency of GBS varies in different geographical areas. Capsular serotyping of the bacterium could result in efficient vaccine designation. Serotyping data of GBS in Iranian pregnant women is limited. The aim of this study was to investigate the GBS molecular capsular serotyping of pregnant women in Yazd, Iran.
In this cross-sectional study, a total of 346 vaginal and urine samples collected from pregnant women were cultured on blood agar and following incubation, the suspected colonies were identified according to standard protocol. Capsular serotyping was carried out by multiplex-polymerase chain reaction assay.
Three hundred forty six samples were collected from pregnant women out of which 57 (16.47%) and 33 (9.5%) samples were identified as GBS of vagina, and urine, respectively. Serotype III was predominant in both vaginal and urine samples by frequencies of 54.4% and 51.5 %, respectively. Other serotypes in vaginal GBS were as II (26.3%), Ia (12.3%), Ib (3.5%), and V (3.5%); while in urine GBS were as Ia (21.2%), II (18.2%), Ib (6.1%), and V (3%).
This study revealed that capsular serotype III of GBS is the dominant serotype among pregnant women in Yazd, Iran. Moreover vaginal and urine GBS serotypes were significantly correlated. These data could be helpful for future possible formulation of a GBS conjugate vaccine.