Molecular detection of Streptococcus agalactiae and its abundant capsular serotypes in vaginal secretions of women with abortion in Isfahan, Iran

Streptococcus agalactiae which is naturally found in the women intestine and vagina, can cause complications leading to the abortion. The aim of this study was molecular detection of Streptococcus agalactiae and its abundant capsular serotypes in vaginal secretions of women with abortion in 2020 in Isfahan. Samples were taken from vaginal secretions of 110 women with abortions referred to different hospitals in Isfahan from April 2019 to March 2020. Patients were asked to fill out a questionnaire containing demographic characteristics. Following isolation, the bacteria were identified by using biochemical tests and PCR. Bacterial capsular polysaccharides were identified by multiplex PCR using specific primers. The results of biochemical and molecular tests showed that among the isolated bacteria from aborted women participating in this study, 20 isolates (18.1%) were Streptococcus agalactiae. The type III capsular serotype had the highest frequency (42.13%). Other serotypes were Ia (18.27%), II (16.73%), V (13.9%), Ib (8.7%), and IX (0.9%). The serotypes VII, VIII, and VIIV were absent in the isolates. The results of this study showed a significant presence of Streptococcus agalactiae in women with abortion with the highest frequent capsular serotype related to the type III. Although this bacterium is a member in the normal flora of women’s vagina, it is one of the most important causes of miscarriage. To better understand the role of this bacterium in the abortion, more investigations, with more efficient methods are needed to be done on the mechanisms of this effect.