Colonization of Streptococcus agalactiae among pregnant patients in Trinidad and Tobago

OBJECTIVE: To assess colonization of Streptococcus agalactiae [group B streptococcus (GBS)], and delineate capsular serotype distribution and antibiotic susceptibility profiles among pregnant women in Trinidad and Tobago. METHODS: Vaginal swabs were collected from 248 pregnant women attending antenatal clinics in northern Trinidad, and processed using standard microbiological laboratory tests to confirm GBS. Polymerase chain reaction detected atr and cps serotype genes. Antimicrobial susceptibility tests were performed using the Kirby–Bauer method, and SPSS Version 25 was used for statistical analysis. Prevalence ratio measured the risk, and P≤0.05 was considered to indicate significance. RESULTS: The GBS carriage rate was 29% (72/248, 95% confidence interval 23.3–34.8), and carriage was significantly associated with variables including gestational diabetes (P=0.042), age 25–35 years (P=0.006), multiparity (P=0.035) and marital status (P=0.006). The most common serotype was type II [47.2% (34/72)], and serotypes V, VI, VII and VIII were not encountered. GBS showed high resistance to amoxicillin-clavulanic acid (37.5%), erythromycin (30.6%), trimethoprim-sulphamethoxazole (58.3%) and tetracycline (97.2%). CONCLUSION: GBS colonization among pregnant women and resistance to commonly used antibiotics are high in Trinidad and Tobago. A population-based study is required to obtain accurate figures in order to improve maternal healthcare services.