Molecular Serotyping and Antibiotic Resistance Profile of Group B Streptococcus Strains Isolated from Iranian Pregnant Women with Urinary Tract Infection

Background

Group B Streptococcus (GBS) can cause serious infections in neonates and pregnant women. GBS may cause urinary tract infections (UTIs). However, molecular epidemiology of such infections is rarely reported. The present study aimed to determine drug resistance patterns and molecular serotyping of GBS isolates in a population of pregnant Iranian women with UTIs.

Methods

A cross-sectional study was conducted during the first half of 2021 in the Department of Biology, East Tehran Branch, Islamic Azad University (Tehran, Iran). Sixty GBS strains isolated from the urine and placenta samples of pregnant women with UTIs were evaluated. The women were aged 19-46 years old at 35 to 37 weeks of gestation. The molecular serotype of GBS isolates was determined using a multiplex polymerase chain reaction, and the disc diffusion method was used to determine the antibiotic susceptibility pattern of isolates for different antibiotics. The association of the GBS serotype with the phenotype of antibiotic resistance was statistically analyzed using SPSS software (version 22.0) with a Chi square test and Cramer's V test. P<0.05 was considered statistically significant.

Results

GBS capsular serotype II was most prevalent (66.7%) followed by serotypes Ib (21.7%), Ia (3.3%), and III (1.7%). The prevalence of non-typeable isolates was significantly low (6.6%). Of the 60 GBS isolates, 18.3% were resistant to penicillin, 81.6% to ampicillin, 23.3% to clindamycin, and 30% to vancomycin; indicating the need for treatment alternatives.

Conclusion

Region-specific information on antibiotic resistance and molecular characteristics of GBS is essential for epidemiological investigations, effective treatment, and vaccine development.

Molecular Characterization of Streptococcus agalactiae Isolates from Pregnant Women in Kathmandu City

Introduction

Group B streptococci (GBS) are globally recognized as one of the leading causes of neonatal sepsis and meningitis and is also known to cause adverse pregnancy outcomes such as stillbirths and miscarriages. Thus, detailed investigation of GBS in pregnant women has special significance in public health related researches.

Objectives

The present study is aimed at evaluating the prevalence of GBS colonization among pregnant women in Kathmandu city.

Methods

The study was carried out among 125 pregnant women at their trimester (35-37 weeks) (during the time period between January and June in 2018). The prevalence was determined by the culture method in HiCrome Strep B Selective Agar Base and then by using the PCR technique. The serotypes were evaluated by multiplex PCR analysis, while the antibiotics susceptibility tests were performed using the disk diffusion method.

Results

Among 125 samples studied, GBS were recorded in 24 samples (implying a prevalence of 19.2%). Furthermore, using the multiplex PCR, among 24 GBS-positive samples, 13 (54.17%) were found to be typeable while 11 (45.83%) were nontypeable. The most abundant serotype recorded in this study was type III (33.33) while the serotypes IV, V, VI, VII, and VIII were not found.

Conclusion

The isolates were sensitive towards some antibiotics such as linezolid and ceftriaxone 100%, whereas penicillin 50% and vancomycin 75% but were resistant to tetracycline and ertapenem. Serotype III was found to be predominant in the samples collected during the study period. The observed prevalence was significantly associated with the gestational period, whereas no relationship was found for other risk factors.