衡阳地区儿童肺炎支原体流行状况及3种基因分型方法比较

摘要

Objective To investigate the prevalence of Mycoplasma pneumoniae ( Mp) infection in children in Hengyang from 2013 to 2016 and to analyze the p1 genotypes of the isolated Mp strains by using polymerase chain reaction-restriction fragment length polymorphism ( PCR-RFLP) , nested polymerase chain reaction (nPCR) and rapid-cycle polymerase chain reaction (Rapid-Cycle PCR).Methods Throat swab samples of children with acute respiratory tract infection were collected from four hospitals in Hengyang , Hu-nan Province from 2013 to 2016.Mp strains in these samples were identified by PCR amplification of the 16S rRNA gene.PCR-RFLP, nPCR and Rapid-Cycle PCR were performed for Mp p1 genotyping in order to fur-ther analyze the genotypes of Mp strains circulating in Hengyang .Results A total of 109 clinical strains of Mp were identified from the 984 throat swab samples .The sensitivities of PCR-RFLP and nPCR for genoty-ping MP strains were both 100％, while that of rapid-Cycle PCR was 98 .17％.All of the three methods showed 100％specificity for genotyping.Of all isolated Mp strains, 78.90％ were p1 gene type Ⅰ and 21.10％were p1 gene typeⅡ(t=93.239, P=0.01).From 2013 to 2016, the annual isolation rates of p1 gene type Ⅰ and type Ⅱ strains were 93.10％, 87.5％, 76.92％, 65.79％ and 6.90％, 12.5％, 23.08％, 34.21％, respectively.The rate of Mp p1 gene type Ⅰinfection decreased over year , while that of p1 gene type Ⅱinfection increased gradually .Conclusion PCR-RFLP, nPCR and rapid-Cycle PCR are reliable for genotyping of Mp p1 gene.The predominant genotype of Mp strains circulating in Hengyang is p 1 gene type Ⅰ, but the incidence of p 1 gene type Ⅱinfection gradually increases from 2013 to 2016 .%目的 了解2013—2016年湖南省衡阳地区儿童肺炎支原体(Mp)感染情况,用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)、巢式PCR(nPCR)和快速循环PCR(Rapid-Cycle PCR)对Mp p1基因进行分型研究.方法 收集2013—2016年衡阳市4家三甲医院儿童急性呼吸道感染咽拭子标本,PCR扩增16S rRNA基因鉴定Mp临床株.用PCR-RFLP、nPCR和Rapid-Cycle PCR对临床株进行p1基因分型,分析2013—2016年衡阳地区Mp的流行情况.结果 从984例咽拭子标本中共鉴定出109株Mp菌株.PCR-RFLP和nPCR对109例Mp菌株分型的敏感性为100％(109/109).Rapid-Cycle PCR分型法的敏感性为98.17％(107/109),3种方法基因分型的特异性均为100％.109例Mp临床株中Ⅰ型分离率为78.90％(86/109),显著高于Ⅱ型菌株检出率(21.10％,23/109,t=93.239,P=0.01).2013—2016年,Ⅰ型逐年检出率分别为93.10％、87.50％、76.92％和65.79％,Ⅱ型逐年检出率分别为6.90％、12.50％、23.08％和34.21％,MpⅠ型菌株检出率逐年减少,而Ⅱ型Mp菌株逐年增加.结论 PCR-RFLP、nPCR和Rapid-Cycle PCR均对Mp分型具有敏感性和特异性,2013—2016年衡阳地区分离的109例Mp临床株主要为Ⅰ型,且逐年由Ⅰ型向Ⅱ型转换.