Streptococcus agalactiae colonization among a cross section of patients attending antenatal clinic in Trinidad and Tobago

Abstract

Purpose: The bacterium Streptococcus agalactiae is found to be common among pregnant women, and in neonates they cause life threatening infections such as sepsis, meningitis, pneumonia and bacteremia. Colonization and serotype distribution are two relevant areas to accurately study the morbidity and mortality within a population. This study was undertaken to assess the colonization of group B streptococci (GBS) in a cross section of pregnant women in an area in Trinidad and Tobago and to delineate their capsular serotype distribution and antibiotic susceptibilities. Methods & Materials: Vaginal swabs were collected and cultured from 248 pregnant women attending public antenatal care in the North Central Region of Trinidad. Standard microbiological laboratory tests were carried out for conventional confirmation of GBS, and then confirmed by polymerase chain reaction (PCR) for the presence of atr gene and cps for GBS serotypes Ia-VIII. Antimicrobial susceptibility tests of the isolates were performed using Kirby Bauer methods. The SPSS vs 25 was used for the statistical analysis. The prevalence ratio was used as the risk measure considering p ≤ 0.05 as significant level with 95% confidence interval. Results: The GBS prevalence was 29% (72/248), CI [23.3-34.8]. There was significant GBS carriage and association with several variables such as diabetes (p=0.042), marital status, 25 – 35 years of age group (p=0.006), multigravida (p=0.035) and marital status (p=0.006). Most common serotype was type II, 47.2% (34/72) and serotypes V, VI, VII and VIII were not encountered. High antibiotic resistance was observed among tested antibiotics; tetracycline 97% (70/72), trimethoprim -sulfamethazole 42% (30/72), piperacillin-tazobactam 38% (27/72), amoxicillin + clavulanic acid 22% (16/72) and cefuroxime 22% (16/72). Conclusion: The prevalence of Streptococcus agalactiae colonization among a cross section of pregnant women in this study was found to be high, and their resistance to commonly used antibiotics in the country was also high. More population based study is required to get an accurate figure of GBS in this area and the entire country for a better maternal health care services.