Genotypic diversity and serotype distribution of group B Streptococcus isolated from women before and after delivery
Genotypic diversity and serotype distribution of group B Streptococcus isolated from women before and after delivery
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DOI：
10.1086/588296
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发表时间：
2008-06-15
影响因子：
11.8
通讯作者：
Davies, H. Dele
中科院分区：
文献类型：
--
作者：
Manning, Shannon D.;Lewis, Maggi A.;Davies, H. Dele
背景大多数关于母体B族链球菌（GBS）定植动力学的研究依赖于荚膜血清分型来确定GBS获得或丧失。区分GBS克隆的新分子方法可能会扩大我们的知识并影响疫苗接种策略。我们使用多位点序列分型（MLST）和GBS荚膜基因簇（cps）基因分型来研究围产期GBS定植的动态。共338株GBS分离株从212名定植妇女中获得，这些妇女参加了先前的前瞻性队列研究，在分娩前（访视1）和分娩后6周（访视2）通过MLST和cps分型进行血清分型和基因分型。在212名女性中，126名在两次访视时均定植，而66名在访视2时丢失，20名获得GBS。338株菌株的MLST鉴定出29种标记不同细菌克隆的序列类型。在两次访视中，126名妇女中有23名（18.3%）发生了序列类型或cps和血清型的变化。特定序列类型与GBS丢失和持续性相关。高龄产妇和分娩期抗生素的使用与持续定植有关。虽然大多数GBS阳性孕妇在围产期稳定定殖，但我们通过应用MLST检测到抗原性不同的GBS克隆随时间的胶囊表达和克隆化的变化。结合流行病学和分子分型数据揭示了与持续定植相关的宿主因素和克隆，以及更容易丢失的克隆。这方面的知识是有用的预防和干预策略，以减少产妇GBS定植的可能性的发展。
Background. Most studies of the dynamics of maternal group B Streptococcus (GBS) colonization have relied on capsular serotyping to define GBS acquisition or loss. Newer molecular methods that distinguish GBS clones may expand our knowledge and influence vaccination strategies. We used multilocus sequence typing (MLST) and GBS capsular gene cluster (cps) genotyping to investigate the dynamics of perinatal GBS colonization.Methods. A total of 338 GBS isolates obtained from 212 colonized women who were enrolled in a prior prospective cohort study were serotyped and genotyped by MLST and cps typing before (visit 1) and 6 weeks after (visit 2) delivery.Results. Of the 212 women, 126 were colonized at both visits, whereas 66 lost and 20 acquired GBS by visit 2. MLST of the 338 strains identified 29 sequence types marking distinct bacterial clones. A change in sequence type or cps and serotype occurred in 23 (18.3%) of the 126 women who were colonized at both visits. Specific sequence types were associated with GBS loss and persistence. Older maternal age and exclusive intrapartum antibiotic use were associated with persistent colonization.Conclusions. Although most GBS-positive pregnant women were stably colonized during the peripartum period, we detected changes in capsule expression and recolonization with antigenically distinct GBS clones over time by applying MLST. Combining the epidemiologic and molecular typing data revealed host factors and clones associated with persistent colonization, as well as a clone that was more readily lost. This knowledge is useful for the development of prevention and intervention strategies to reduce the likelihood of maternal GBS colonization.