Common Colonization Genes Profiling and BOX-PCR Based Genotyping of Streptococcus agalactiae from Pregnant Women in Tehran, Iran

Streptococcus agalactiae or group B streptococcus (GBS) is a prominent cause of severe neonatal infections. GBS is a part of the intestinal and vaginal normal flora. Maternal colonization is recognized as the main path of GBS transmission. GBS is a pathobiont that changes from a non-symptomatic mucosal carriage state to a significant bacterial pathogen, causing major infections.

This study aimed to investigate the concomitant presence of major colonization genes, including ftsA, ftsB, lmb, and sfbA, and to determine the genetic relatedness of clinical GBS isolates.

The GBS isolates were obtained from urinary and placental samples of pregnant women with a urinary tract infection, who were admitted to a hospital in Tehran, Iran. The presence of some major colonization factors was investigated via multiplex PCR assay. Genotyping of the isolates was performed using the BOX-PCR fingerprint technique with a BOX-A1R primer. Next, the data were analyzed using the UPGMA method and the coefficient of Jaccard in NTSYS software.

A total of 60 GBS isolates were examined in this study. The concomitant presence of target colonization genes was observed in all isolates. The BOX-PCR discriminated GBS isolates into six different genetic clusters at a 60% cutoff point. The majority of isolates (80%) from both clinical samples were clustered into genotypes 2, 6, and 4, while the rest (20%) were distributed equally into three different genotypes.

Determining the colonization associated genes and genetic polymorphism in a different geographical area provides the epidemiological basis for the prevention of GBS infections in pregnant women and infants.