【作者】 徐建； 陆宇； 付雷； 王彬； 郑梅琴； 李芃； 赵伟杰；

【Author】 Beijing Tuberculosis and Thoracic Tumor Research Institute No.97 Ma Chang,Tongzhou District,Beijing 101149 Xu Jian,LuYu,Fu Lei et al

【机构】 北京市结核病胸部肿瘤研究所；

【摘要】 目的测定我国部分地区北京基因型与非北京基因型结核分枝杆菌的毒力,研究结核分枝杆菌基因型与毒力及耐药性与毒力的关系,为防治结核病提供依据。方法从我国7省市（北京、天津、河北、内蒙古、山西、河南、新疆）选择结核分枝杆菌15株进行毒力测定。运用Spoligotyping分型方法鉴定北京基因型菌株。药物敏感性实验采用MABA法,测定药物包括异烟肼（H）、利福平（R）、乙胺丁醇（E）、链霉素（S）、卡那霉素（KM）、氧氟沙星（OFX）。BALB/C小鼠尾静脉感染5×10⁷cfu的结核分枝杆菌,观察小鼠生存周期,分别于感染后30天、60天分别解剖小鼠称取脾重,大体肉眼病变观察,进行肺、脾活菌计数,并将感染后60天的小鼠肺、脾进行组织病理学检查。通过小鼠的半数死亡时间,脾、肺活菌计数,组织病理学检查等比较结核分枝杆菌的毒力强弱。结果选取的15株结核分枝杆菌中,9株是北京基因型菌株,其中7株北京基因型菌株比6株非北京基因型菌株毒力强。毒力最强的北京基因型菌株致小鼠的半数死亡时间为20天,生存期为23天,毒力最弱的非北京基因型菌株到感染后60天时仅死亡一只,肉眼观察肺表面光滑,但其肺活菌计数仍达到9.84±0.13log₁₀CFU,组织病理学显示肺部组织大面积实变。15株菌株中,敏感株1株,单耐异烟肼3株,敏感株毒力在15株中居中,异烟肼耐药株毒力较敏感株弱。结论结核分枝杆菌的毒力与基因分型有关,绝大多数北京基因型的比非北京基因型的菌株毒力强。单耐异烟肼的菌株毒力较敏感株毒力减弱。更多还原

【Abstract】 Objective To measure the virulence of Beijing genotype and non-Beijing genotype Mycobacterium tuberculosis in some regions of China and to investigate the relationship between genotype and virulence,the relationship between drug resistant and virulence Methods Fifteen clinical strains were collected from seven provinces and municipalities of China including Beijing,Tianjin,Hebei,Neimenggu,Shanxi,Henan, Xinjiang.Beijing genotype of M.tuberculosis was identified by spacer oligonucleotide typing.Drug susceptibility testing was performed using MABA assay and the test drugs were Isoniazid（H）,Rifampin（R）,Ethambutol（E）, Streptomycin（S）,Kanamycin（Km）,Ofloxacin（Ofx）.In this study,we used the BALB/c mouse model of by the lateral tail vein route with 5×10⁷cfu/mouse to examine the course of infection in terms of strain virulence（mouse survival,spleen and lung bacillary load,histopathology）.At 30day,60day post-challenge,a group of mice was culled for spleens weight,visible gross pathology,spleens and lungs colony-forming unit assay,respectively.At 60day post-infection,histopathology of mice lungs and spleens were performed.Combined with the above assays, we compared the virulence of different strains.Results Among the 15 M.tuberculosis clinical isolates,9 isolates were Beijing genotypes M.tuberculosis.The virulence of 7 Beijing genotypes strains was higher than the other 6 Non-Beijing genotypes strains.The survival time of the highest virulent Beijing genotype strain was 23 days and the 50%lethal time was 20days.Only 1 mouse died after 60 days of infection in the lowest virulent Non-Beijing genotype strain and the surface of lungs were smooth.However,9.84±0.131og₁₀ CFU of the lung bacillary loads was observed and histopathology showed a large area of lung tissue consolidation.Among the 15 strains,1 strain was sensitive,3 strains were Isoniazid resistant.The virulence of sensitive strain was intermediate in 15 strains and the virulence of Isoniazid resistant strains was lower than sensitive strain.Conclusion The virulence of M.tuberculosis is correlated with genotypes.Most Beijing genotype strains are higher virulent than non-Beijing strains.The Isoniazid resistant strains were lower virulent than sensitive strain.更多还原