Clinical Study And Genotyping On The Beijing Lineage Of Mycobacterium Tuberculosis

IDENTIFICATION AND ANALYSIS OF DRUG RESISTANCEOF MYCOBACTERIUM TUBERCULOSIS BEIJING LINEAGEObjective: Preliminary understanding of tuberculosis hospital Beijinglineage of Mycobacterium tuberculosis infection and drug resistancecharacteristics.Methods: Clinically isolated bacterial strains from tuberculosispatients treated in the National Tuberculosis Clinical Center (Beijing ChestHospital, Capital Medical University) in China were continuously collected.Drug susceptibility was determined by the absolute concentration method,Anti-tuberculosis drugs, including Isoniazid、Streptomycin、Ethambutol、Rifampicin、Rifabutin、Amikacin、Capreycin、ETO、PAS、Ofloxaxin、Levofloxacin、Rifapentine。All samples were collected for acid-fast stainingand p-Nitrobenzoic acid (PNB) and thiophene-2-carboxylic acid hydrazide(TCH) identification. The RD105deletion was investigated for all samples.Results: Of the421bacterial strains collected,413(98.1%) wereidentified as M.TB，8（1.9%）were identified as NTM. The Beijing lineage of M.TB was defined by the deletion of RD105. There were389strains ofM.TB with the RD105deletion. The Beijing lineage of M.TB accounted for94.2%(389/413) of M.TB strains in this study. The single-drug resistancerate was82.3%(95%CI:78.5-86.2). The multiple-drug resistant (MDR-TB)rate was27.4%(95%CI:22.9-31.9), and the extensively drug-resistant(XDR-TB) rate was12.4%(95%CI:9.1-15.7), Ethambutol had the highestdrug resistance rate,42.7%(95%CI:35.1-50.3), followed by streptomycinat41.7%(95%CI:34.0-49.4). There results were different from thosereported by the Chinese drug resistance baseline surveyConclusion: A higher proportion of patients with tuberculosis hospitalinfection Beijing lineage of Mycobacterium tuberculosis, Ethambutolresistance rates are highest.Beijing lineage M.TB may contact severerefractory tuberculosis. BEIJING LINEAGE OF MYCOBACTERIUMTUBERCULOSIS CLINICAL SIGNIFICANCE OFSUBTYPING VARIABLE TANDEM REPEAT (VNTR)COMBINED SINGLE NUCLEOTIDE POLYMORPHISM(SNP)Objective: Explore Beijing lineage of Mycobacterium tuberculosis carried subtyping clinical significance and clinical characteristics of eachsubtype.Methods: Clinically isolated bacterial strains from tuberculosispatients treated in the National Tuberculosis Clinical Center (Beijing ChestHospital, Capital Medical University) in China were continuously collected.MTB Beijing lineages were sub-classified using8or51SNPs and standardVNTR-15genotyping. Correlations between clinical characteristics(medical history, imaging findings, drug resistance spectrum, and clusteringrate) and the ancient and modern sublineages were calculated. M.TB Beijinglineages were sub-classified using8or51SNPs and standard VNTR-15genotyping. Correlations between clinical characteristics (medical history,imaging findings, drug resistance spectrum, and clustering rate) and theancient and modern sublineages were calculated.Results: With51points Beijing lineage of Mycobacterium tuberculosisis divided into two subtypes of ancient and modern。In8poins the“modern”-type Beijing Inineage accounted for85.5%(324/379), while the“ancient”-type Beijing lineage was14.5%(55/379). Two kinds of typingmethods for ancient and modern subtyping is consistent.No clinicalcharacteristics were correlated with either lineage (P>0.05). Modern andancient Beijing lineage M.TB compared to ancient strains was0clusters,clusters of modern strains was23.8%. Conclusion: Beijing lineage of Mycobacterium tuberculosis were nosignificant differences in clinical characteristics between the two subtypesbetween ancient and the modern. Modern and ancient Beijing lineageM.TB have different propagation efficiency. Higher rates of modernclusters, dissemination stronger. TB infection by Mycobacteriumtuberculosis genotype analysis, forecasting its therapeutic effect andprognosis. SNP SITES FOR PROTEIN STRUCTURE AND FUNCTIONPREDICTIONObjective: Discussion Mycobacterium tuberculosis Beijing lineagemolecular mechanism of adaptation environment, suggesting that theSNP variation related proteins of Mycobacterium tuberculosis caused byMycobacterium tuberculosis and thus presumably adapt relevantcharacteristicsMethods: Among SNPs that could be used for classification, Rv0245(S103F) and Rv2494(V48A) were selected to predict protein function andstructure based on the Protein Variation Effect Analyzer (PROVEAN) scores. The FR-t5algorithm was used for template selection and alignment based onthe target sequences. Based on template selection and alignment in aprevious report, MODELLER (http://salilab.org/modeller/) was used forstructure modeling of target sequences and the RASP program foroptimization of side chain modeling to obtain the final three-dimensionalstructure model. To better analyze the S103F polymorphism in Rv0245andthe V48A polymorphism in Rv2494, the CIS-RR program was used toperform single-site mutations at corresponding sites and further optimize theoverall side chains to eliminate clashes based on the structural models of thetarget genes.Results: Rv2494might be a toxin protein. V48A severely affected thebinding capacity of its pocket region thus further affecting the efficiency ofRv2494under the physiological condition. Rv0245might be a flavinadenine dinucleotide (FAD)-or flavin mononucleotide (FMN)-dependentoxidoreductase. S103F changed polar Ser into non-polar Phe, which mightincrease Rv0245’s recognition and binding of FAD or FMN, thus increasingRv0245activity.Conclusion: the polymorphisms of Rv0245(S103F) and Rv2494(V48A) in the modern sublineage relate to the dormant status of MTB. Thechanges in toxin-antitoxin activity directly affect whether MTB enters adormant state, while FAD-or FMN-dependent oxidoreductases will breakdown the components of caseous necrosis in the host to provide evidence of MTB’s survival after it enters the dormant state.