B族链球菌不同检测方法的效果评价

Evaluation of the effects of different detection methods of Group B streptococcus

目的 分析质谱快速鉴定法、选择肉汤培养后涂平板法、实时荧光PCR法和胶体金免疫层析法在孕妇B群链球菌(GBS)定植筛查中的应用效果。方法 同时采用质谱快速鉴定法、选择肉汤培养后涂平板法、细菌培养法、实时荧光PCR法和胶体金免疫层析法对278例孕35-37周孕妇阴道下端或肛周拭子进行GBS筛查。以细菌培养法作为金标准方法,评价质谱快速鉴定法、选择肉汤培养后涂平板法、实时荧光PCR法和胶体金免疫层析法的诊断性实验性能。结果 细菌培养法阳性率9.4%,选择肉汤培养后涂平板培养法阳性率10.4%,实时荧光PCR法阳性率18.3%,质谱快速鉴定法阳性率为6.8%,胶体金免疫层析法阳性率为12.2%,不同方法检出率比较差异有统计学意义(P<0.05)。选择肉汤培养后涂平板法准确度最高,为98.9%;灵敏度最高,为100.0%;漏诊率最低。质谱快速鉴定法特异度最高,为99.6%;阳性预测值最高,为94.7%;误诊率最低,为0.4%;但漏诊率最高,为30.8%。实时荧光PCR法特异度为88.0%;灵敏度为77.0%;误诊率最高,为12.0%。胶体金免疫层析法特异度为96.0%,灵敏度为92.3%,准确度为95.7%。4种诊断性实验阴性预测值均较高,达96.0%以上。4种诊断性实验灵敏度、特异度比较差异有统计学意义(P<0.05)。结论 胶体金免疫层析法适合作为门诊大规模初步筛查、基层医院常规筛查方法。实时荧光定量PCR适用于孕妇GBS的快速筛查。选择肉汤培养后涂平板法可作为普通细菌培养法的改良方法,有条件的医院可作为常规筛查方法。快速质谱鉴定法是一种简单快速、成本低、准确率较好的孕妇GBS筛查方法。

Objective Analyze the application effects of rapid mass spectrometry identification method, selective broth culture followed by plating method, real-time PCR method and colloidal gold immu-nochromatography method in the screening of colonization of group B streptococcus(GBS) in pregnant women.Methods At the same time, using mass spectrometry rapid identification method, selective broth culture followed by plating method, bacterial culture method, real-time PCR method and colloidal gold immunochromatography method were used to perform GBS on 278 cases of pregnant women at 35-37 weeks of gestation from the lower vagina or perianal swab Screening.Bacterial culture method was used as the gold standard method to evaluate the diagnostic experimental performance of mass spectrometry rapid identification method, selective broth culture and plate coating method, real-time PCR method and colloidal gold immunochromatographic method.Results The positive rate of bacterial culture method was 9.4%,the positive rate of plate culture method after broth culture was 10.4%,the positive rate of real-time PCR method was 18.3%,the positive rate of mass spectrometry rapid identification method was 6.8%,and the positive rate of colloidal gold immunochromatographic method was 6.8%.12.2%,the detection rate of different methods has a statistically significant difference(P<0.05).After selecting broth culture, the method of spreading the plate has the highest accuracy, 98.9%;the sensitivity is the highest, 100.0%;the missed diagnosis rate is the lowest.The mass spectrometry rapid identification method has the highest specificity, which is 99.6%;the positive predictive value is the highest, which is 94.7%;the misdiagnosis rate is the lowest, which is 0.4%;but the missed diagnosis rate is the highest, which is 30.8%.The specificity of real-time PCR method is 88.0%;the sensitivity is 77.0%;the misdiagnosis rate is the highest, 12.0%.The specificity of colloidal gold immunochromatography is 96.0%,the sensitivity is 92.3%,and the accuracy is 95.7%.The negative predictive values of the four diagnostic tests were all high, reaching over 96.0%.The sensitivity and specificity of the four diagnostic tests were statistically significant(P<0.05).Conclusion Colloidal gold immunochromatography is suitable for large-scale preliminary screening in outpatient clinics and routine screening in primary hospitals.Real-time PCR is suitable for rapid screening of pregnant women’s GBS.The plating method after broth culture can be used as an improved method of ordinary bacterial culture, and hospitals with conditions can be used as a routine screening method.Rapid mass spectrometry is a simple, fast, low-cost and accurate screening method for pregnant women’s GBS.