北京、广东、宁夏三地结核分支杆菌DNA指纹的应用研究

目的 分析“北京家族”结核分支杆菌,从分子流行病学角度探讨北京、广东及宁夏三地结核分支杆菌的分布特征。方法 采用Gel compare4．1软件对来自三地的206株结核分支杆菌的插入序列IS6110 DNA指纹图谱进行数字化,经互联网与世界结核分支杆菌DNA指纹库进行相似性比较;同时应用该软件对上述菌株行聚类分析;构建标准的结核分支杆菌Spoligotyping(间隔区寡核苷酸分型法)DNA指纹方法;用χ^2检验比较不同组别肺结核病人临床分离菌株成簇率的差别,同时计算相对危险度(OR)。结果 206株结核分支杆菌的IS6110 DNA指纹图谱与DNA指纹图谱库相比较,未发现相同者。56．8％(117／206)的结核分支杆菌IS6110 DNA指纹相似值在1．00—0．65之间,且它们的Spo1igotyping指纹图谱均与“北京家族”结核分支杆菌相一致;分组统计显示：男性组与女性组、年龄≥42岁组与＜42岁组成簇率之间差异有显著性(P＜0．05),OR值为男性4．43,95％CI：0．94—28．76;＜42岁为5．06,95％CI：1．00—34．34。其他各组之间差异无显著统计学意义(P＞0．05)。结论 “北京家族”结核分支杆菌在三地呈较高水平的流行;结核分支杆菌在男性和＜42岁人群中的传播频率较女性和≥42岁人群为高,且男性和＜42岁可能是三地结核病近期传播的危险因素。利用结核分支杆菌的DNA指纹图谱和互联网技术,可以实现结核分支杆菌传染源全球范围的追踪。

DNA fingerprinting of Mycobacterium tuberculosis strains from Beijing,Guangdong and Ningxia

OBJECTIVE: To explore the epidemic distribution of Mycobacterium tuberculosis isolates from Beijing, Guangdong and Ningxia, and to determine M. tuberculosis strains of the "Beijing Family". METHODS: Two hundred and six IS6110 DNA fingerprinting patterns of M. tuberculosis strains from three provinces (city) were transferred to digital data, compared with the world M. tuberculosis DNA fingerprinting database, and then clustered by Gel compare 4.1 software. The clustering values in different patients with tuberculosis were compared by chi(2) test. Risk factors for recent transmission were calculated using odd ratios. RESULTS: No M. tuberculosis strains were found the same as those of DNA fingerprint database. 56.8% (117/206) fingerprinting patterns of M. tuberculosis shared by least two-thirds of the IS6110 fragments and their Spoligotyping fingerprinting patterns were consistent with those of M.tuberculosis strains of the "Beijing Family". There were significant differences between female and male, different age groups (< 42 years old) and older (>or= 42 years old) (P < 0.05). Odd ratio was 5.06 in the group younger than 42 years old (95% CI: 1.00 - 34.34) and was 4.43 (95% CI: 0.94 - 28.76) in males. CONCLUSION: M. tuberculosis strains of "Beijing Family" were popular in Beijing, Guangdong and Ningxia. Men and younger age group (< 42) were shown to be infected by identical strains more often than women and older aged which might play an important role in the recent transmission of tuberculosis in these areas. IS6110 DNA fingerprinting of M. tuberculosis could be used to trace the source of tuberculosis infection.