CAJ | 학술논문

目的探讨四川盆地(重庆、四川地区)流行的结核分枝杆菌(MTB)群体遗传学特征.方法对413株源自四川盆地的MTB进行长序列多态性(LSP)谱系鉴定,采用x2检验分析不同谱系MTB在人群中的分布差异.对菌株进行15位点数目可变串联重复序列基因分型,评价各位点的分辨力.构建N-J树分析其系统进化;构建最小跨度树以模拟群体菌株的遗传结构;采用分子方差分析不同谱系MTB的群体间遗传分化;采用贝叶斯模型计算菌株最近共祖年代.结果通过LSP可将413株MTB分为两大谱系,其中北京谱系占56.2％(232/413),欧美谱系占43.8％(181/413).两谱系MTB在人群中的分布(性别、年龄、民族以及菌株耐药性)差异无统计学意义(P＞0.05).北京谱系MTB的N-J树呈放射状分布,最小跨度树中有72.4％(168/232)的菌株被划分到同一“克隆复合群”;欧美谱系MTB的N-J树呈枝状分布,最小跨度树中呈现出多个“克隆复合群”.北京谱系MTB在该地区有显著的群体间遗传分化(FST=0.018 91,P＜0.05),而欧美谱系MTB群体间遗传分化不显著(FST=0.005 19,P＞0.05).欧美谱系MTB中最大菌株复合群的最近共祖年代为723 (95％CI:517 ～ 946)年.结论北京谱系和欧美谱系MTB在四川盆地以“互相对抗”形式流行;两谱系MTB的群体间遗传分化存在差异;欧美谱系MTB的侵入可能与一次历史事件(约720年前的战争)有关.
목적 탐토사천분지(중경、사천지구)류행적결핵분지간균(MTB)군체유전학특정.방법 대413주원자사천분지적MTB진행장서렬다태성(LSP)보계감정,채용x2검험분석불동보계MTB재인군중적분포차이.대균주진행15위점수목가변천련중복서렬기인분형,평개각위점적분변력.구건N-J수분석기계통진화;구건최소과도수이모의군체균주적유전결구;채용분자방차분석불동보계MTB적군체간유전분화;채용패협사모형계산균주최근공조년대.결과 통과LSP가장413주MTB분위량대보계,기중북경보계점56.2％(232/413),구미보계점43.8％(181/413).량보계MTB재인군중적분포(성별、년령、민족이급균주내약성)차이무통계학의의(P＞0.05).북경보계MTB적N-J수정방사상분포,최소과도수중유72.4％(168/232)적균주피화분도동일“극륭복합군”;구미보계MTB적N-J수정지상분포,최소과도수중정현출다개“극륭복합군”.북경보계MTB재해지구유현저적군체간유전분화(FST=0.018 91,P＜0.05),이구미보계MTB군체간유전분화불현저(FST=0.005 19,P＞0.05).구미보계MTB중최대균주복합군적최근공조년대위723 (95％CI:517 ～ 946)년.결론 북경보계화구미보계MTB재사천분지이“호상대항”형식류행;량보계MTB적군체간유전분화존재차이;구미보계MTB적침입가능여일차역사사건(약720년전적전쟁)유관.
Objective To explore the population-genetics characteristics of Mycobacterium tuberculosis (MTB) prevailing at the Sichuan basin of China.Methods A total of 413 MTB strains collected from Sichuan basin were genotyped by large sequence polymorphism (LSP) and 15 loci variable number tandem repeat (VNTR).Difference between the distribution of lineage population was analyzed by x 2-test and the discriminatory ability of each VNTR locus was evaluated under the Hunter-Gaston Discriminatory Index (HGI).Both phylogeny on population level and genetic structure were demonstrated through N-J tree and the Minimal Spanning Tree (MST).Genetic differentiation of different lineage strains was analyzed by Analysis of Molecular Variance (AMOVA).Time of the Most Recent Common Ancestor (TMRCA) was calculated based on the Bayesian model.Results Four hundred and thirteen MTBs were divided into two major lineages,in which the Beijing lineage accounted for 56.2％ (232/413) and the Euro-American lineage for 43.8％ (181/413).There was no significant difference of population distribution between the two lineages (P＞0.05).The N-J tree of Beijing lineage MTB presented distinctly "star-like" and 72.4％ strains were grouped to one clonal complex in MST.The Euro-American lineages MTB presented "branch-like" in N-J tree and were grouped into multiple clonal complexes in MST.There was significant genetic differentiation in Beijing lineage MTBs between Chongqing and Sichuan (FST=0.018 91,P＜0.05),but not in the Euro-American lineage MTB (FST=0.005 19,P＞0.05).TMRCA of the largest clonal complex in Euro-American lineage MTB appeared to be 723 (95％ CI:517-946) years.Conclusion Both Beijing lineage and Euro-American lineage MTBs were competitively prevalent in the Sichuan basin.There was some difference noticed between the two lineages referring to genetic differentiation.The invasion of Euro-American lineages MTB to the basin area might be associated with a war occurred in this area about 720 years ago.