Occurrence of Streptococcus agalactiae serogroups in isolates from pregnant women of Peshawar

Abstract

Introduction: Maternal rectovaginal colonization during pregnancy by Group B Streptococcus agalactiae (GBS) is one of the major preventable and easily recognizable causes of neonatal morbidity and mortality but in Pakistan, GBS is inadequately explored.

Objectives: To estimate the frequency of recto-vaginal GBS colonization and its serogroup distribution among pregnant women in their 3^rd trimester presenting to antenatal clinics of Hayatabad Medical Complex (HMC), Peshawar.

Materials & Methods: This descriptive cross-sectional study was conducted at HMC from October 18, 2019, to February 05, 2020, through serial sampling of 220 pregnant women. Two swabs, one from vagina and the other from anorectal region were taken. The samples were transported to the laboratory in Amies transport medium, first inoculated in Todd-Hewitt broth and then subcultured on 5% sheep blood. After gram staining and microscopy, gram positive cocci were examined for catalase production and Lancefield latex agglutination to confirm GBS. The confirmed GBS were serogrouped by using Immulex Strep-B kit (54991, SSI DIAGNOSTICA, Denmark). A structured questionnaire was used to record data. Data were analysed using SPSS version 22 for descriptive statistics.

Results: The GBS maternal colonization was found in 22(10%) cases. The serogroups identified among the GBS positive cases were Ia, Ib, II, III, VI and IX. No untypeable GBS strain was isolated. The identified strains were serogroup II (13, 59.09%), Ia (10, 45.45%), Ib (05, 22.72%), III (01, 4.54%), VI (01, 4.54%) and IX (01, 4.54%).  In 6 cases the same serogroups were identified, while in one case 3 different serogroups were isolated (both from vagina and rectum).

Conclusion: Favorable conditions exist for the occurrence of invasive GBS disease in pregnant women in Peshawar.