3种改良B族链球菌检测方法的检测效果比较

Efficacy of three modified detection methods for group B Streptococcus:a comparative study

目的比较3种改良B族链球菌(GBS)检测方法的检测效果。方法纳入300例妊娠35~37周妇女,采集其阴道-直肠分泌物。分别用细菌培养法、免疫层析法、实时荧光定量PCR法直接检测样本GBS,并对样本进行增菌18~24 h、36~48 h后的浓缩菌液进行GBS检测。比较同一方法增菌前后的阳性检出率,以及增菌前和增菌18~24 h后3种方法的阳性检出率。结果增菌前、增菌18~24 h和36~48 h后,细菌培养法对GBS的阳性检出率分别为2.33%、9.33%、10.67%,免疫层析法的阳性检出率分别为5.33%、13.67%、14.67%,PCR法的阳性检出率分别为9.00%、12.67%、14.00%。各种方法增菌18~24 h、36~48 h后的阳性检出率均高于直接检测(均P<0.05),而增菌18~24 h、36~48 h后的阳性检出率差异无统计学意义(均P>0.05)。增菌前PCR法阳性检出率高于培养法(P<0.05),而增菌18~24 h后3种方法的阳性检出率比较差异无统计学意义(P>0.05)。结论检测前增菌18~24 h能提高细菌培养法、免疫层析法、PCR法对GBS的阳性检出率,且前两种方法能获得与PCR法相似的检测效果。

Objective To compare the detection effects of three modified detection methods for group B Streptococcus(GBS).Methods A total of 300 pregnant women of 35-37 weeks gestation were recruited,and their vaginal-rectal secretions were collected as samples.Bacteria culture,immunochromatography and real-time fluorescence quantitative PCR were used for direct detection of GBS in the samples,and for GBS detection in concentrated bacterial fluid after 18-24 hours or 36-48 hours of bacterial enrichment.The positive detection rates before and after bacterial enrichment were compared in the same method,and the positive detection rates of the three methods were compared before and 18-24 hours after bacterial enrichment.Results Before bacterial enrichment,after 18-24 hours or 36-48 hours of bacterial enrichment,the positive detection rates for GBS were 2.33%,9.33%and 10.67%by bacterial culture,were 5.33%,13.67%and 14.67%by immunochromatography,and were 9.00%,12.67%and 14.00%by PCR,respectively.For each method,the positive detection rate after 18-24 hours or 36-48 hours of bacterial enrichment was higher than that of direct detection(all P<0.05),but there was no statistically significant difference between the positive detection rates after 18-24 hours and 36-48 hours of bacterial enrichment(all P>0.05).Before bacterial enrichment,the positive detection rate of PCR was higher than that of bacterial culture(P<0.05);however,no statistically significant difference in positive detection rate among the three methods 18-24 hours after bacterial enrichment(P>0.05).Conclusion Bacterial enrichment for 18-24 hours before detection can increase the positive detection rate for GBS by bacterial culture,immunochromatography or PCR,and the first two methods achieve a similar detection efficacy as PCR.