结核性脑膜炎临床分离株基因型和耐药表型的特征分析

The characteristic analyses in genotype and drug resistance of clinical isolates from the patients with tuberculous meningitis

目的了解导致结核性脑膜炎(TBM)的致病菌在基因型和耐药表型方面的特征。方法利用间隔区寡核苷酸分型法(Spoligotyping)和数目可变串联重复序列(VNTR)分型法对25株TBM临床分离菌株进行基因分型;采用MGIT(mycobacteria growth indicator tube)960液体和比例法固体药敏试验分别对所选15种药物:异烟肼(INH)、利福平(RFP)、乙胺丁醇(EMB)、吡嗪酰胺(PZA)、链霉素(S)、卡那霉素(Km)、阿米卡星(Am)、卷曲霉素(Cm)、莫西沙星(Mfx)、氧氟沙星(Ofx)、左氧氟沙星(Lfx)、对氨基水杨酸(PAS)、乙硫异烟胺(Eto)、丙硫异烟胺(Pto)、环丝氨酸(Cs)进行药敏实验。结果Spoligotyping分型法确定了在25株TBM临床分离株中有20株为北京基因型,占80.0%(20/25),2株为T1基因型,另外3株分别为T2型、LAM6型及未知型;VNTR有2株成一簇,基因型一样;25株TBM分离株中耐多药结核性脑膜炎(MDR-TBM)占12.0%(3/25),广泛耐药结核性脑膜炎(XDR-TBM)占4.0%(1/25),耐氟喹诺酮类的菌株占8.0%(2/25),都属于北京基因型;任意耐药的菌株占48.0%(12/25),其中83.3%(10/12)为北京基因型;全敏感者占52.0%(13/25),其中76.9%(10/13)为北京基因型。结论北京基因型在耐药TBM中所占比例很高,尤其是MDR-TBM,较其他基因型更易引起脑脊液生化的改变;耐氟喹诺酮类的菌株所占比例最少,提示临床上氟喹诺酮类药物对治疗TBM会有很好的疗效。

Objective To study the characteristics in genotype and drug resistance of clinical isolates from the patients with tuberculous meningitis. Methods Twenty-five clinical isolates from the patients with tuberculous meningitis （TBM） were analyzed by Spoligotyping, variable numbers of tandem repeats （VNTR）, 15 antituberculo- sis drug susceptibility testing methods, in which 15 drugs were as following., isoniazid, rifampicin, ethambutol, pyrazinamide, streptomycin, kanamycin, amikacin, capreomycin, moxifloxacin, ofloxacin, levofloxacin, para amino salicylic acid, ethionamide, prothionamide, cycloserine. Results Of 25 M. tuberculosis isolates, 20 （80. 0M） were Beijing genotype, 2 were T1 genotype, 3 were other genotypes （including T2, LAM6, and unclassified genotype）. 12.0%（3/25）were multi-drug resistant （MDR）, and 4. 0~ （1/25） strains were extensive drug-resistant （XDR）. 8. 0% （2/25） strains were resistant to fluoroquinolones, all belong to Beijing genotype. 48. 0% （12/25） strains were resistant to any drug, in which 83.3%（10/12）were Beijing genotype; 52.0%（13/25） strains were sensitive, in which 76.9% （10/13） strains were Beijing genotype. Conclusion Beijing genotype strains were possibly associ- ated with drug-resistant tuberculosis and may act as the main epidemic strain of TBM. Few strains were resistant to fluoroquinolones, which may play an important role in TBM treatment.