The Construction Of Anti-Tuberculosis Drug Resistance Database And Evaluation In Vitro Activity

Tuberculosis is a long-standing infectious disease caused by Mycobacterium tuberculosis and is still one of the three major infectious diseases that endanger human health worldwide.The emergence of drug-resistant tuberculosis has made the challenge of tuberculosis more serious.Early diagnosis and treatment of drug-resistant tuberculosis is a key way to control drug resistance.Comprhensive information of mechanisms and mutation sites contributing to the development of drug resistance are important to improve the molecular diagnosis and guide clinicians to improve the treatment options.At the same time,a systematic strain panel with different resistance levels and mechanisms is essential at all stages of drug screening and efficacy evaluation.This study mainly summarized the resistance genes and targets of two first-line anti-tuberculosis drugs,isoniazid and streptomycin to establish an anti-tuberculosis drug resistance locus database.A mycobacteria strain panel for isoniazid and streptomycin was initially formed,and 106 compounds have been evaluated for the antituberculosis activity.Cycloserine is an effective group C anti-tuberculosis drug.Drug susceptibility tests(DST)of cycloserine in practice provides rough estimate of the drug resistance of Mycobacterium strains.But the reliability and reproducibility cannot be guaranteed and provide poor clinical predictive values.In this study,the effectiveness of serial cycloserine solutions incubated at 37? for 1 to 29 days were tested using the Alamar Blue assay,and cycloserine in culture medium was analyzed by UPLC-MS.The analysis of serial cycloserine solutions incubated at 37? revealed that cycloserine itself is continuously degraded in culture medium.This amount of degradation was sufficient to alter the minimum inhibitory concentration(MIC)value of Mycobacterium strains and therefore could not be ignored,although it was more stable than in phosphoric acid buffer.The different test periods and the degradation of cycloserine were responsible for the lack of agreements between the different DST methods and the low reliability of this in vitro test.By adjusting with the incubation time depended degradation ratio of cycloserine,more accurate MIC values may be obtained allowing for improved coincidence between in vitro experiment and clinic use.This in turn would provide more effective and reliable experimental data to guide the decision making of clinicians regarding anti-tuberculosis treatment.