2013-2017年河南省中牟县结核分枝杆菌Spoligotyping分型及比较研究

Investigation of clinical Mycobacterium tuberculosis isolates with spoligotyping from 2013-2017 in Zhongmu county, Henan province

目的了解河南省中牟县临床分离结核分枝杆菌(MTB)的基因型分布特征,为结核病防控提供分子流行病学依据。方法收集2013-2017年中牟县临床分离培养的352株MTB,采用间隔区寡核苷酸分型(Spoligotyping)技术对临床分离株进行分型,将Spoligotyping分型结果与SITVIT2数据库进行比较确定菌株的基因家族,比较各年基因型分布的差异性。结果 352株临床分离MTB经Spoligotyping分型分为31个基因型,北京家族占85.8%(302/352);其次为T家族(包括T1、T2、T3),占10.2%(36/352);12种基因型为无对应型别,占4.0%(14/352)。2013-2017年北京基因型家族的比率分别为89.3%(50/56)、85.0%(68/80)、84.2%(80/95)、88.1%(59/67)、83.3%(45/54),各年间北京型比例差异无统计学意义(χ~2=1.348,P=0.853);2013-2017年T家族的比率分别为8.9%(5/56)、12.5%(10/80)、14.7%(14/95)、6.0%(59/67)、5.6%(3/54),各年间T家族比例差异无统计学意义(χ~2=4.311,P=0.366);2013-2017年无对应家族的比率分别为1.8%(1/56)、2.5%(2/80)、1.1%(1/95)、6.0%(4/67)、11.1%(6/54),各年间无对应家族比例差异有统计学意义(χ~2=11.182,P=0.025)。结论中牟县结核分枝杆菌临床分离株中北京基因型菌株为主要流行株,但是近两年无对应基因型别逐渐增多,提示结核病疫情有新的变化。

Objective To study the genotypic constitution of clinical Mycobacterium tuberculosis(MTB)isolates in Zhongmu county,Henan province,and provide epidemiological data for the TB control.Methods 352 MTB clinical strains isolated from 2013 to 2017 were collected from Zhongmu county,Henan province,and were genotyped by spoligotyping.The spoligotyping results were compared with SITVIT2 database to determine genotypes of the strain,and the differences of genotype distribution in different years were compared.Results The clinical isolates of MTB were classified into 31 genotypes by Spoligotyping,85.8%(302/352)in Beijing family,10.2%(36/352)in modern TB strains(T1,T2,T3),and 4.0%(14/352)in 12 new genotypes.From 2013 to 2017,the ratio of Beijing genotype family was 89.3%(50/56),85.0%(68/80),84.2%(80/95),88.1%(59/67)and 83.3%(45/54),respectively,and there was no significant difference in the ratio of Beijing genotype between different years(χ~2=1.348,P=0.853).From 2013 to 2017,the ratio of T family was 8.9%(5/56),12.5%(10/80)and 14.7%(14/95),respectively,and there was no significant difference in the proportion of T families among different years(χ~2=4.311,P=0.366).From 2013 to 2017,the ratio of new type was 1.8%(1/56),2.5%(2/80),1.1%(1/95),6.0%(4/67)and 11.1%(6/54),respectively,and there was significant difference in the proportion of corresponding families among different years(χ~2=11.182,P=0.025).Conclusion The strains of Beijing genotypes in Mycobacterium tuberculosis in Zhongmu county were still the main epidemic strains,but the new types had gradually increased in the last two years,suggesting that there were new changes in the epidemic situation of tuberculosis.