Isolation and Characterization of Streptococcus agalactiae and its Capsular Antigen, Along with Mycoplasma hominis and Listeria monocytogenes, as Abundant Infections in Women with Abortion in Iran

 The accurate diagnosis of infections can significantly enhance preventative measures against abortion.

 The rates of Streptococcus agalactiae, Mycoplasma hominis, and Listeria monocytogenes were investigated in the vaginal secretions of women with abortion. Furthermore, this study aimed to detect S. agalactiae capsular types by multiplex Polymerase Chain Reaction (PCR) and sequencing.

 The study collected vaginal samples obtained from a cohort of women with abortions of unknown cause from various healthcare facilities across Iran, as well as their counterparts who did not experience any reproductive issues. Molecular identification was performed by a multiplex PCR protocol for the amplification of specific regions within the bacterial 16S rRNA gene. The capsular polysaccharide of S. agalactiae was identified by multiplex PCR of the caps gene. Then, the sequences of the amplified gene were analyzed by Mega X. Finally, some factors that exerted a noteworthy influence on the likelihood of miscarriage were determined.

 The study found S. agalactiae, M. hominis, and L. monocytogenes in the vaginal secretions of women with abortion, with respective frequencies of 4.54%, 2.7%, and 9.09%, which were more than the frequencies in the pregnant healthy women. The caps III (4%) and caps V (6%) genes were identified in the S. agalactiae isolates. The sequences of caps III or caps V did not show any differences among the isolates containing each gene.

 The findings demonstrated the significance of preemptively managing prevalent infections and investigating risk factors in women prior to pregnancy. No difference in the sequences of the caps genes is promising for the adoption of vaccination and therapeutic strategies.