部分cpsA-cpsB血清型预测系统预测94株肺炎链球菌血清型分析

Analysis of serotype results of 94 streptococcus pneumoniae isolates with partial cpsA-cpsB serotype prediction system

目的 评价部分cpsA-cpsB血清型预测系统在预测肺炎链球菌血清型的应用价值.方法 用荚膜肿胀实验对首都医科大学附属北京儿童医院提供的94株肺炎链球菌进行传统分型,以其分型结果为血清型金标准.按照文献进行目的基因cpsA-cpsB片段扩增、测序、序列编辑及比对.结果 94株肺炎链球菌菌株,经荚膜肿胀反应检测,83株确定血清型/群,11株为未分型菌株.在83株确定血清型的菌株中,67株菌株目的片段聚合酶链式反应（PCR）呈阳性结果（占80.72％）;在这67株菌株中,60株（占89.55％）菌株血清型的预测结果和金标准一致或者包含了金标准.其中,12株血清型为19F的PCR阳性菌株中,10株的预测结果和金标准一致,另外2株的预测结果分别为6A、23F/10A.在19株血清型为19A的PCR阳性菌株中,18株的预测结果和金标准一致,另外1株的预测结果为35F/47F.在10株血清型为14的PCR阳性菌株中,9株的预测结果和金标准一致,另外1株的预测结果为19A.7株血清型为6B的PCR阳性菌株的预测结果为6A/6B.在4株血清型为23F的PCR阳性菌株的预测结果为23F/10A.11株未分型的菌株中,3株（占27.27％）PCR阳性,血清型预测结果分别为6A/6C、6A/6B、19A.结论 部分cpsA-cpsB血清型预测系统在预测我国肺炎链球菌血清型方面有一定的临床应用价值.

Objective To evaluate the application of partial cpsA-cpsB serotype prediction system as a serotyping method for streptococcus pneumonia.Methods Ninety-four isolates in this study were provided by Microorganism Research Room of Beijing Pediatric Research Institution,Beijing Children＇s Hospital Affiliated to Capital Medical University.The quelling test was applied to determine gold standard of serotypes of isolates.Polymerase chain reaction （PCR）,sequencing,sequence data management and alignment were implemented previously.Results Eighty-three out of all 94 isolates were serotyped by quelling reaction,and 11 isolates were non-serotype isolates.Among the 83 isolates,67 （80.72%） isolates got positive PCR results and 60 （89.55%）isolates got results consistent with gold standard or containing gold standard.Among 12 isolates belonging to 19F,10 isolates were correctly predicted,and 2 isolates were predicted to be 6A,23F/10A.Among 19 isolates belonging to serotype 19A,1 isolate was predicted to be 35 F/47F,and the other 18 isolates were correctly predicted.Among 10 isolates belonging to serotype 14,9 isolates got results consistent with gold standard,and 1 isolate was predicted to be 19A.All 7 isolates belonging to serotype 6B were predicted to be 6A/6B and 4 isolates belonging to 23F were predicted to be 23F/10A.3 of 11 （27.27%） non-serotype isolates got positive PCR results and were predicted to be 6A/6C,6A/6B,19A.Conclusions Partial cpsA-cpsB sequencing system is a useful method for detecting streptococcus pneumoniae serotypes.