• Distribution of Virulence Genes of Streptococcus agalactiae isolated from Pregnant Women in Bushehr
  • Somayyeh Gharibi,1,* Mahnaz Gholipour shahrak,2 Fahimeh Tavakoli,3 Saeed Tajbakhsh,4 Abbas Yadegar,5 Zeinab Asen,6
    1. Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran
    2. Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran
    3. Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran
    4. Department of Microbiology and Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
    5. Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
    6. Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran


  • Introduction: Streptococcus agalactiae, GBS, is an important pathogen in neonates and pregnant women that normally colonizes the vagina and opportunistically leads to invasive diseases. GBS included several pathogenic genes that expression is directly involved in the prognosis of disease, bacterial survival and invasion. The aim of this study was to evaluate the frequency of group B streptococcal pathogenesis genes by PCR in pregnant women in Bushehr. Material and Methods: In this cross-sectional descriptive study, 25 GBS-positive samples isolated from pregnant women aged 35-42 weeks of pregnancy were studied. After DNA extraction and ensuring its purity, PI-1, PI-2a, PI-2b, PGi, fbsB, lmb and scpB genes were examined through specific primers.
  • Methods: In this study, 25 GBS-positive samples isolated from pregnant women aged 35-42 weeks of pregnancy were studied. After DNA extraction and ensuring its purity, They were confirmed by a housekeeping gene primer, pgi by PCR, and then PI-1, PI-2a, PI-2b, fbsB, lmb and scpB genes were examined through specific primers.
  • Results: The presence of pgi gene as housekeeping gene was confirmed in all strains. The sCpB gene was positive in 9 samples (36%). PI-1, PI-2a and PI-2b genes were found in 19 samples (76%), 1 sample (4%) and 1 sample (4%), respectively. The prevalence of fbsB was positive in 100% of the samples and the prevalence of lmb was positive in 92% of the isolates. 17 samples (68%) had at least one type of PI-1 cell. In one case (4%) there was a combination of PI-1 / PI-2b and in one case (4%) there was a combination of PI-1 / PI-2a, while 5 samples (20%) did not have any pilus genes. In 4 samples (16%) there were 4 pathogens and in 2 cases (8%) there were 5 sCpB / PI-1 / PI-2a / fbsB / lmb factors (except PGi). 15 cases (60%) carried 3 pathogens. The predominant gene profile was PI-1 /lmb / fbsB with a prevalence of 76%. The scpB+lmb interaction was seen in 36% of the strains.
  • Conclusion: This study showed that the prevalence of virulence genes among the existing strains is highly variable. However, the isolates evaluated in it may contain other known and unknown virulence genes. These genes may also be expressed differently in various populations. That is why more research needs to be done on the prevalence of more virulence genes in more pregnant women.
  • Keywords: Streptococcus agalactiae, GBS, Pregnant women, Virulence genes, PCR