Emerg Infect Dis. 2021;27(9):2279-2287. doi: 10.3201/eid2709.210049.
We retrospectively investigated mother-to-infant transmission of group B (GBS) in 98 cases of late-onset disease reported during 2007–2018 by a network in Italy. Mothers with full assessment of vaginal/rectal carriage tested at prenatal screening and at time of late onset (ATLO) were included. Thirty-three mothers (33.7%) were never GBS colonized; 65 (66.3%) were vaginal/rectal colonized, of which 36 (36.7%) were persistently colonized. Mothers with vaginal/rectal colonization ATLO had high rates of GBS bacteriuria (33.9%) and positive breast milk culture (27.5%). GBS strains from mother–infant pairs were serotype III and possessed the surface protein antigen Rib. All but 1 strain belonged to clonal complex 17. GBS strains from 4 mother–infant pairs were indistinguishable through pulsed-field gel electrophoresis. At least two thirds of late-onset cases are transmitted from mothers, who often have vaginal/rectal carriage, positive breast milk culture, or GBS bacteriuria, which suggests heavy maternal colonization.
我们回顾性研究了意大利网络在 2007 年至 2018 年期间报告的 98 例晚发型疾病中 B 组（GBS）母婴传播的情况。纳入了在产前筛查和晚期发病时（ATLO）进行了全面评估阴道/直肠携带情况的母亲。33 位母亲（33.7%）从未定植 GBS；65 位母亲（66.3%）阴道/直肠定植，其中 36 位母亲（36.7%）持续定植。ATLO 时阴道/直肠定植的母亲有较高的 GBS 菌尿症（33.9%）和阳性母乳培养（27.5%）率。母婴配对的 GBS 菌株为血清型 III，具有表面蛋白抗原 Rib。除 1 株外，其余均属于克隆复合体 17。4 对母婴配对的 GBS 菌株通过脉冲场凝胶电泳无法区分。至少三分之二的晚发型病例是由经常阴道/直肠定植、母乳培养阳性或 GBS 菌尿症的母亲传播的，这提示母亲有严重定植。
