Background: Group B streptococci (GBS) is an important pathogen involved in stillbirths, neonatal deaths and neurological defects, and the occurrence of multi-drug resistance (MDR) is an alarming issue. This study determined the prevalence of GBS colonization in pregnant women and newborns, the proportion of vertical transmission, antimicrobial susceptibility profiles of isolates, and the factors associated with colonization and vertical transmission.
Methods: A cross-sectional study was conducted from March 1, 2021 to June 30, 2021, at selected health facilities of Bahir Dar city. Vaginal-recto swabs from 292 pregnant women and pooled ear, nasal and umbilical swabs from 292 newborns were collected. GBS were identified following standard microbiological protocols. Antimicrobial susceptibility testing was performed using modified Kirby–Bauer disk diffusion method and interpreted by the accepted 2020 CLSI M100 guidelines. Logistic regression analysis was computed.
Results: Overall, 54 (18.5%) of pregnant women and 22 (7.5%) of newborns had GBS colonization. The proportion of GBS vertical transmission was 22 (40.7%). Group B Streptococcus isolates scored susceptibility to penicillin, ampicillin and vancomycin with 88.9%, 90.7%, and 96.3% for pregnant women and 86.4%, 90.9% and 95.9% for newborns, respectively. A high percentage of non-susceptibility was found for clindamycin and erythromycin with 33.3% and 25.9% for pregnant women and 31.8% and 22.7% from newborns, respectively. Besides, 19 (35.2%) GBS from pregnant women and 8 (36.4%) from newborns were MDR. Group B streptococci colonization was significantly associated with delivery before 37th week of gestation (AOR=2.77, 95% CI 1.14– 6.68) and history of stillbirth (AOR=3.13, 95% CI 1.13– 8.70).
Conclusion: Pregnant women vaginal-recto GBS colonization and transmission to newborns connected with MDR are a matter of concerns. Although non-susceptible GBS isolates are obtained, penicillin and vancomycin are relatively effective. The use of clindamycin, erythromycin and ceftriaxone should be guided by antimicrobial susceptibility testing. Genetic analysis is recommended to exactly identify the epidemiology of GBS strains, vertical transmission and antimicrobial resistance at the country level.



中文翻译：

---

B 组链球菌阴道-直肠定植、对新生儿的垂直传播、巴赫达尔市选定卫生设施的抗菌药物敏感性概况和相关因素：一项横断面研究

背景： B族链球菌（GBS）是导致死产、新生儿死亡和神经系统缺陷的重要病原体，多药耐药（MDR）的发生是一个令人担忧的问题。本研究确定了 GBS 在孕妇和新生儿中的定植率、垂直传播的比例、分离株的抗菌药物敏感性概况以及与定植和垂直传播相关的因素。
方法：一项横断面研究于 2021 年 3 月 1 日至 2021 年 6 月 30 日在巴赫达尔市的选定卫生机构进行。收集了 292 名孕妇的阴道-直肠拭子和 292 名新生儿的合并耳、鼻和脐拭子。GBS 是按照标准微生物方案鉴定的。使用改进的 Kirby-Bauer 纸片扩散法进行抗菌药敏试验，并由公认的 2020 CL​​SI M100 指南进行解释。计算逻辑回归分析。
结果：总体而言，54 名 (18.5%) 孕妇和 22 名 (7.5%) 新生儿有 GBS 定植。GBS垂直传输的比例为22（40.7%）。B组链球菌分离株对青霉素、氨苄西林和万古霉素的敏感性分别为孕妇和新生儿分别为88.9%、90.7%和96.3%和86.4%、90.9%和95.9%。克林霉素和红霉素的不敏感率很高，孕妇分别为 33.3% 和 25.9%，新生儿分别为 31.8% 和 22.7%。此外，19例（35.2%）孕妇GBS和8例（36.4%）新生儿为MDR。B 组链球菌定植与妊娠 37 周前的分娩（AOR=2.77, 95% CI 1.14-6.68）和死产史（AOR=3.13, 95% CI 1.13-8.70）显着相关。
结论：与耐多药相关的孕妇阴道直肠 GBS 定植和传播给新生儿是一个值得关注的问题。虽然获得了不敏感的GBS分离物，但青霉素和万古霉素相对有效。克林霉素、红霉素和头孢曲松的使用应以药敏试验为指导。建议进行遗传分析，以准确识别国家层面 GBS 菌株的流行病学、垂直传播和抗菌素耐药性。