妊娠晚期感染B族链球菌孕妇早产的危险因素及其pbp2x基因突变分析

Analysis of risk factors for preterm birth and pbp2x gene mutation in pregnant women infected with group B streptococcus in the third trimester of pregnancy

目的 分析某院感染B族链球菌(GBS)孕妇发生早产的危险因素及观察早产孕妇感染GBS的pbp2x基因突变情况。方法 选取2022年1月至2023年5月在该院分娩且感染GBS的孕妇199例,根据早产与否分为观察组(41例)和对照组(158例)。采用二分类logistic回归模型和受试者操作特征(ROC)曲线分析感染GBS的孕妇发生早产的危险因素;对早产孕妇的GBS样本进行pbp2x基因一代测序分析。结果 199例感染GBS孕妇中发生早产41例,发生率为20.6%。Logistic回归分析显示,年龄[比值比(OR)=1.151,P=0.004)]和口服葡萄糖耐量试验(OGTT)异常项数(OR=2.995,P<0.001)是感染GBS孕妇发生早产的独立危险因素。两危险因素联合预测早产的曲线下面积(AUC)为0.783,最佳敏感度为75.6%,特异度为69.0%,较单项危险因素预测价值高。pbp2x基因测序发现3个错义突变(1129G>A、1148T>G、1528A>G),未发现影响GBS对青霉素敏感性的基因突变。结论 年龄和OGTT异常项数是感染GBS孕妇发生早产的危险因素,两者联合预测的效能优于单项,早产孕妇感染的GBS中尚未发现影响青霉素敏感性的pbp2x基因突变。

Objective To analyze the risk factors for preterm birth in pregnant women with group B streptococcus(GBS) infection in a hospital and investigate the pbp2x gene mutation of GBS in pregnant women with preterm birth.Methods A total of 199 pregnant women with GBS infection who delivered in the hospital from January 2022 to May 2023 were selected and divided into the observation group and the control group according to whether they were preterm or not.Binary logistic regression model and receiver operating characteristic curve(ROC) were used to analyze the risk factors of preterm birth in pregnant women with GBS infection.First generation sequencing of pbp2x gene was performed on GBS samples from pregnant women with preterm birth.Results Among the 199 cases pregnant women with GBS infection,41(20.6%) had preterm birth.Logistic regression analysis showed that age [odds ratio(OR)=1.151,P=0.004] and the number of abnormal items in oral glucose tolerance test(OGTT)(OR=2.995,P<0.001) were independent risk factors for preterm birth in pregnant women with GBS infection.The area under the curve(AUC) of the combination of the two risk factors for preterm birth was 0.783,the best sensitivity was 75.6%,and the specificity was 69.0%,which was higher than that of single risk factor.Three missense mutations(1129G>A,1148T>G,1528A>G) in pbp2x gene were found by Sanger sequencing.No mutation was found that could reduce the susceptibility of GBS to penicillin.Conclusion Age and the number of abnormal items in OGTT are risk factors for preterm birth in pregnant women with GBS infection,and the combination of the two factors is better than each one alone in predicting preterm birth.No mutation of pbp2x gene affecting penicillin sensitivity has been found in GBS from pregnant women with preterm birth.