Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Sciences, Johannesburg, South Africa.
Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Sci Rep. 2017 Nov 28;7(1):16454. doi: 10.1038/s41598-017-16757-9.
Group B Streptococcus (GBS) recto-vaginal colonisation in pregnant women is the major risk factor for early-onset invasive GBS disease in their newborns. We aimed to determine the association between serum antibody levels against 11 GBS surface proteins and recto-vaginal acquisition of GBS colonisation during pregnancy. Sera collected from pregnant women at 20-25 weeks and ≥37 weeks of gestation age were measured for IgG titres against GBS surface proteins using a multiplex immunoassay. Women were evaluated for recto-vaginal colonisation every 4-5 weeks. We observed that the likelihood of becoming colonised with GBS during pregnancy was lower in women with IgG titres ≥200 U/mL against gbs0233 (adjusted OR = 0.47 [95% CI: 0.25-0.89], p = 0.021) and ≥85 U/mL for gbs1539 (adjusted OR = 0.44 [95% CI: 0.24-0.82], p = 0.01) when comparing between women who acquired GBS colonisation and those that remained free of GBS colonisation throughout pregnancy. IgG titres (U/mL) specific to BibA and Sip were higher in pregnant women colonised with GBS (380.19 and 223.87, respectively) compared to women with negative GBS cultures (234.42 and 186.21, respectively; p < 0.01) at ≥37 weeks gestation. Antibodies induced by gbs0233 and gbs1539 were associated with a reduced likelihood of recto-vaginal GBS acquisition during pregnancy and warrant further investigation as vaccine targets.
B 组链球菌（GBS）在孕妇直肠-阴道定植是其新生儿发生早发型侵袭性 GBS 疾病的主要危险因素。本研究旨在确定血清中针对 11 种 GBS 表面蛋白的抗体水平与孕妇直肠-阴道 GBS 定植获得之间的相关性。在妊娠 20-25 周和≥37 孕周采集孕妇血清，使用多重免疫分析检测针对 GBS 表面蛋白的 IgG 滴度。每 4-5 周评估一次孕妇直肠-阴道定植情况。我们发现，针对 gbs0233 的 IgG 滴度≥200 U/mL（调整后的 OR=0.47[95%CI：0.25-0.89]，p=0.021）和针对 gbs1539 的 IgG 滴度≥85 U/mL（调整后的 OR=0.44[95%CI：0.24-0.82]，p=0.01）的女性在怀孕期间发生 GBS 定植的可能性较低，与整个怀孕期间未发生 GBS 定植的女性相比。与未发生 GBS 定植的孕妇相比，在≥37 孕周发生 GBS 定植的孕妇针对 BibA 和 Sip 的 IgG 滴度（U/mL）更高（分别为 380.19 和 223.87），而未发生 GBS 定植的孕妇 IgG 滴度（U/mL）分别为 234.42 和 186.21（p<0.01）。针对 gbs0233 和 gbs1539 诱导的抗体与降低怀孕期间直肠-阴道 GBS 定植的可能性相关，值得进一步研究作为疫苗靶点。
