山西省一起家庭聚集性百日咳病例的实验室诊断

Laboratory diagnosis of a family cluster of pertussis in Shanxi

目的分析山西省一起百日咳家庭聚集性病例的实验室诊断情况,总结百日咳鲍特菌的病原学及流行病学特点。方法对疑似百日咳病例进行病例资料收集,采集病例(患儿)及其密切接触者(母亲)的鼻咽拭子样本进行百日咳鲍特菌分离鉴定及核酸检测,并对菌株进行基因测序分析。结果患儿及其母亲鼻咽拭子样本百日咳鲍特菌培养均为阳性,患儿鼻咽拭子核酸检测阴性,母亲鼻咽拭子核酸检测阳性。菌株基因测序结果显示,多位点序列分型均为ST-2型,属于ST-2克隆群,与美国国立生物技术信息中心数据库中890株百日咳鲍特菌基因组进行聚类分析,发现与25株百日咳鲍特菌遗传进化关系较近。结论对该起百日咳家庭聚集性病例进行实验室检测确诊,提供了准确的病原学信息,为百日咳的诊断及疫情监测提供参考。

Objective To analyze the epidemiologic and etiologic characteristics of the laboratory diagnosis of a family cluster of pertussis in Shanxi province and provide evidence to improve the clinical and laboratory diagnosis and detection of pertussis.Methods The incidence data of pertussis in a family were collected.The nasopharyngeal swabs of the patient(child)and the close contact(mother)were used for isolation,identification,nucleic acid detection of Bordetella pertussis,and the gene sequencing of the strains was conducted.Results The nasopharyngeal swabs of the child and his mother were positive for B.pertussis culture.The nasopharyngeal swab of the child was negative but the nasopharyngeal swab of his mother was positive in nucleic acid test.The multilocus-sequence typing(MLST)gene sequencing results showed that all the strains were ST-2,belonging to ST-2 complex.Cluster analysis was conducted with the genomes of 890 strains of B.pertussis download from National Center for Biotechnology Information(NCBI)database,and it was found that the MLST of the strains was closely related to the genetic evolution of 25 strains of B.pertussis.Conclusion The child and his mother were confirmed to be infected with B pertussis by laboratory tests,indicating a family cluster of pertussis.Laboratory testing can provide timely and accurate etiological information for the diagnosis of pertussis and the surveillance of pertussis epidemic.