High prevalence of penicillin-resistant group B Streptococcus among pregnant women in Northwest Ethiopia

Group B Streptococcus (GBS) is a normal constituent of the female genital and gastrointestinal flora but remains a leading cause of perinatal bacterial infections, including endometritis, bacteremia, chorioamnionitis, and urinary tract infections in pregnant women. In Ethiopia, reported GBS colonization rates among pregnant women range from 7.2 to 25.5%. This study aimed to determine the prevalence, antimicrobial susceptibility patterns, and associated factors of GBS colonization among pregnant women attending antenatal care (ANC) at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia. An institutional-based cross-sectional study was conducted from March 1 to May 30, 2021. After obtaining written consent, sociodemographic data were collected using a structured questionnaire, conveniently. A total of 210 recto-vaginal swabs were collected, inoculated into Todd-Hewitt broth, and sub-cultured on 5% blood agar. Antimicrobial susceptibility testing was performed using the disk diffusion method following Clinical and Laboratory Standards Institute 2020 guidelines. Data were entered and cleaned in Epi Data version 3.1 and analyzed using SPSS version 20. Binary logistic regression identified associations between variables, with a P value ≤ 0.05 considered statistically significant. The overall GBS colonization was 13.3% (28/210). Married women had significantly higher odds of colonization (AOR 5.774; 95% CI 1.074-31.03; P = 0.041), while those with a history of abortion had lower odds (AOR 0.294; 95% CI 0.102-0.850; P = 0.024). Most isolates were susceptible to chloramphenicol (96.4%). Resistance rates were highest for erythromycin (71.4%) and penicillin (67.9%), followed by ampicillin (64.3%), azithromycin (46.4%), vancomycin (46.4%), and ceftriaxone (32.1%). Half of the isolates were multidrug-resistant. GBS colonization among pregnant women in the study area warrants clinical attention due to its associated high antibiotic resistance. Being married and abortion had statistically significant associations with colonization. Therefore, clinicians could implement routine GBS screening for all pregnant women attending ANC to reduce GBS colonization. Routine GBS screening may help reduce neonatal sepsis, pneumonia, and meningitis by guiding timely intrapartum antibiotic prophylaxis.