邢台地区275株结核分枝杆菌VNTR基因分型及表型耐药研究

Study on VNTR genotypes and drug resistance phenotypes of 275 mycobacterium tuberculosis clinical isolates from Xingtai area

目的初步了解邢台地区结核分枝杆菌临床分离株的基因型多态性及表型耐药特征,探讨各基因型与表型耐药之间的相关性。方法收集2014年1月至2014年10月期间在邢台市传染病医院就诊的结核病患者经临床分离培养得到的结核分枝杆菌菌株及相应病例背景资料,采用15位点数目可变串联重复序列分析(VNTR)进行基因分型研究,采用比例法进行一线抗结核药的药物敏感性试验。运用Bio Numerics5.0软件进行聚类分析,运用SPSS16.0软件进行数据分析。结果该地区的总耐药率为31.6%,初始耐药率为24.2%,获得性耐药率为56.3%。复治患者的耐药率显著高于初治患者耐药率。275株结核分枝杆菌可分为145种VNTR基因型,其中165株菌被聚类为35个簇,110株菌的基因型为独特基因型。VNTR对所有菌株的HGDI值为0.9838。成簇型菌株与独特型菌株在患者年龄、性别、职业、地势、治疗史、吸烟史、糖尿病史等的分布差异无统计学意义。成簇型菌株与独特型菌株的单耐药水平和耐多药水平也无统计学差异。结论邢台地区的结核分枝杆菌临床分离株呈现明显的基因多态性。本研究尚未发现VNTR基因分型与表型耐药的相关性。

Objective To understand the characteristics of genotypes and drug resistance phenotypes of my-cobacterium tuberculosis clinical isolates from Xingtai and to explore the association of genotypes and drug resistance phenotypes. Methods The mycobacterium tuberculosis clinical strains isolated from TB patients in the Fifth Hospital of Xingtai and the corresponding clinical information of the patients were collected from January 2014 to October 2014. The 15-locus variable number tandem repeats （VNTR） was used to genotype the strains, and the first-line an-ti-TB drug susceptibility testing was performed using the proportion method. Clustering analysis was done by BioNu-merics 5. 0 software and statistical analysis was done by SPSS 16. 0 software. Results The total drug resistance rate of MTB in this district was 31. 6% , the initial drug resistance rate was 24. 2% , and the acquired drug resistance rate was 56. 3% . The drug resistance level of re-treatment was significantly higher than that of new cases. The 275 MTB strains were divided into 145 VNTR genotypes, of which 165 strains were clustered into 35 groups and 110 strains were individual types. The HGDI value of VNTR was 0. 9838. There was no significant difference in age, gender, occupation,geographical location,treatment history,smoking history or diabetes history, and no statistical difference was observed between the clustered genotypes and individual genotypes in mono-drug resistance rate and multi-drug resistance rate. Conclusion The mycobacterium tuberculosis isolates from Xingtai exhibit high genetic diversity. No correlation is observed between VNTR genotypes and drug resistance phenotypes in this study.