摘要目的 研究感染北京基因型MTB菌株的危险因素及其与耐药和临床症状的相关性.方法 2007年9月至2008年3月痰涂片阳性肺结核患者172例(男132例,女40例),平均年龄(56±10)岁.收集痰标本,采用罗氏培养法,培养阳性菌株行DNA提取,使用基因RD105缺失法及7个位点可变数量串联重复序列(VNTR-7)方法进行基因分型.两组间率的比较采用χ~2检验,定量资料比较采用t检验.结果 172例痰标本中共得到培养阳性菌株116株,其中非MTB菌株4株,MTB菌株112株.来自上海及江浙地区的MTB菌株中北京基因型占86.6%(84/97),非北京基因型占13.4%(13/97).女性患者的北京基因型(31/84,36.9%)明显高于非北京基因型(1/13,7.7%),初治患者中CD_4/CD_8<1者北京基因型(17/41,41.5%)明显高于非北京基因型(0/7,0%),差异均有统计学意义(χ~2值分别为4.436和4.494,均P<0.05).采用VNTR-7分型方法,北京基因型菌株可分为31种基因型,各型之间的分布不均匀,有4种基因型集中了47.6%(40/84)的MTB菌株及43.6%(17/39)的耐药菌株.结论 上海及江浙地区的MTB菌株以北京基因型为主,女性及免疫功能低下的初治肺结核患者可能是感染北京基因型菌株的危险因素.北京基因型菌株与耐药及临床症状可能无明显相关性.

abstractsObjective To analyze the risk factors for the infection of Beijing genotype Mycobacterium tuberculosis (MTB) and the relationship to drug resistance and clinical symptoms. Methods Sputum samples were collected from patients with pulmonary tuberculosis who were admitted to the hospital during September, 2007 to March, 2008. The sputum was cultured with L-J method, and then the bacterial DNA was isolated and genotyped with VNTR-7 (variable-number tandem repeats, VNTR ) and RD105 deletion method respectively. The association between different genotypes and risk factors was analyzed. Results A hundred and sixteen clinical sputum isolates were obtained from 172 positive sputum cases. There were 112 isolates of MTB, and 4 isolates of non-tuberculosis mycobacterium (NTM). Among the 97 isolates from Shanghai, Zhejiang and Jiangsu areas, Beijing genotype accounted for 86.6% (84/97), and non-Beijing genotype for 13.4% (13/97). Among the risk factors, female gender, and CD_4/CD_8 <1 in patients with newly-treated tuberculosis, were associated with higher rate of Beijing genotype, χ~2= 4.436, 4. 494 and all P <0. 05, respectively. The Beijing genotype isolates were subdivided into 31 VNTR-7 types, and the distribution of quantity and resistance among different VNTR-7 genotypes was not even. A large number of MTB isolates (47.6%, 40/84) and drug resistant isolates (43.6%, 17/39) were among 4 VNTR-7 genotypes. Conclusions Beijing genotype is the most prevalent MTB in Shanghai, Zhejiang and Jiangsu areas. Female gender and low CD_4/CD_8 ratio in patients with newly-treated TB are risk factors for infecting Beijing genotype MTB, which may have no relationship with drug resistance and clinical symptoms.