An Investigation Beijing Genotype And Drugs Resistance Of Mycobacterium Tuberculosis In The Four Province(Autonomous Regions) Of North China

Objectives In this study we investigated the genotyping characteristics and the status of the drugs resistance(DR)to the first-line drugs streptomycin(SM),rifampicin(RFP),isoniazid(INH)and ethambutol(EMB)of Mycobacterium tuberculosis(MTB),and analysed influencing factors of DR and the correlation between the genotyping and DR in the four provinces and autonomous regions(Gansu,Xizang,Xinjiang,Inner Mongolia)of north China to provide basic scientific evidence for the prevention and control of drug-resistant tuberculosis(TB).Methods 662 clinical MTB isolateswere collected from the four provinces and autonomous regions.The drug susceptibility of these clinical isolates was determined by means of the drug susceptibility test(DST)of proportion method.The genotype of MTB isolates was conducted with using spacer oligonucleotide typing(Spoligotyping).Cluster analysis was completed by BioNumerics software 5.1.Statistical analyses were carried out with Chi-square and Logistic regression analysis using SPSS software 22.0.The level of significance was set at P(27)0.05.ResultsThere were 87 kinds of genotypes of 662 clinical MTB isolates genotyped by Spoligotyping,and the gene polymorphism was13.14%.And the most frequent strains were Beijing family strains accounted for 82.18%.Of the tested strains Beijing genotype in Tibet,Inner Mongolia,Gansu and Xinjiang were 91.41%,84.77%,79.55% and 63.30% respectively.CAS family was found in Xizang and Xinjiang.Of 662 clinical MTB isolatestested with DST,the total drug resistant rate was 41.84%,and the total drug resistant rate(68.56%)of there treatment cases was significantly higher than that of theinitial treatment cases(27.77%).The percentages of drug resistance in Xizang,Gansu,Xinjiang and Inner Mongolia were 64.42%,50.00%,40.37% and 27.81% and the single-drug resistance rate and the multi-drug resistance(MDR)rate was 12.24% and 20.69%,respectively.The percentages of drug resistance to SM,INH,RFP and EMB were 29.00%,28.55%,28.10% and 8.46%,respectively.The highest drug resistance rate was that to SM in initial treatment cases(18.94%)and to RFP in retreatment cases(53.28%)respectively.Logistic regression analysis results showed that the influence factors might be the case types.The risk of drug resistance and MDR in retreatment patients was 4.876(95%CI 3.387?7.020)and 7.398 times(95%CI 4.703?11.637)higher than that in the initial treatment patients respectively.And the risk of drug resistance and MDR in Xizang were the highest.But there were no statistically significant between drug resistance and gender,age and Beijing genotype respectively(P﹥0.05).Conclusions Beijing genotype is dominate in north China.We found unique CAS genotype in Xizang and Xinjiang.The status of MTB multi-drug resistance is very serious in the north China,especially in Xizang.The retreatment is a risk factor for drug resistance and MDR.