| Background and ObjectiveThe 2017 WHO global TB report shows that 10.4 million people worldwide are suffering from TB,1.8 million people died of TB in 2016,and TB has become the world's number one killer of infectious diseases.Poor management of TB,improper use of antibiotics,use of ineffective drug formulations,and premature interruption of treatment can lead to drug resistance in Mycobacterium tuberculosis and can lead to transmission.China is one of the countries with more severe drug-resistant TB outbreaks,and currently estimates that there are 120,000 MDR-TB patients in China.WHO has listed China as one of the countries with high MDR-TB burden.The prevention and treatment of multidrug resistance has the problems of low rate of discovery and lower cure rate.How to control MDR-TB effectively has become an urgent task for TB control in the world,and also an important challenge for TB prevention and control in China.Therefore,it is of great significance to explore and evaluate the new early diagnosis technology of drug resistant TB and to find and treat drug-resistant patients in time.One of the most widely used techniques for screening drug-resistant TB in China is the susceptibility test of anti-tuberculosis drugs.The biggest flaw of this method is that the detection period is too long to help the doctor make the best treatment plan in time.In recent years,the field of molecular biology diagnosis of tuberculosis has developed rapidly,and the techniques of gene chip,GeneXpert and Hain Line Probe Assay can not only be used to diagnose tuberculosis,but also can detect drug resistance of some anti-TB drugs.HAIN Line Probe Assay is a diagnostic technique developed by Hain LifeScience,Germany,which can determine whether Mycobacterium tuberculosis is resistant to rifampicin and Isoniazid by detecting mutations in rpoB,katG and inhA genes.This trial aims to evaluate the application of the technique in the early diagnosis of MDR-TB by comparing the HAIN Line Probe Assay with the traditional Mycobacterium drug sensitivity test(DST).To analyze the drug-resistant genes of patients diagnosed with MDR-TB(MDR-TB)and to explore the major gene loci that lead to MDR-TB in the region.Methods387 cases of smear-positive TB were randomly selected from May 2015 to February 2016 in outpatient or inpatient treatment of infectious diseases Hospital of Henan Province(Zhengzhou sixth People's Hospital),of which 271 were male,116female,and average age(39.3±17.5)years old.The Hain linear probe technique and the solid culture of Mycobacterium were carried out to test the acid-positive biological samples of the patients in the group,and the drug susceptibility tests of Mycobacterium strains were carried out by traditional ratio method(DST).From the Laboratory Information Management System(LIS)query two methods from the sample to receive the results of the audit report time used,that is,sample turnaround time(TAT),do a good test record.The results of HAIN Line Probe Assay and drug sensitivity test were compared and analyzed.Statistical processing using Excel software and SPSS 19.0statistical software for each group of case information,experimental results of data collation analysis,quantitative data in the mean±standard deviation(x±s);The difference between different groups of qualitative data was measured by the card-square test,p<0.05 that the difference was statistically significant and the Kappa value was calculated to determine the consistency of the two methodsResults1.In the process of culture,2 samples were contaminated,1 samples were cultured negative and no further drug sensitivity test was performed.Another 3 cases of smear-positive samples were detected by HAIN Line Probe Assay and the results were invalid.Therefore,the above 7 cases were excluded,and finally 380 patients with smear-positive TB continued the study.2.The HAIN Line Probe Assay'_S average sample TAT was(28.77±10.67)hours,while DST's average sample TAT was(1508.87±153.97)hours.3.Compared to DST,the sensitivity of HAIN Line Probe Assay to the detection of Rifampin(RIF)was 82.92%,the specificity was 96.12%,and the,kappa value was0.743.Both methods are highly consistent in detecting whether RIF was resistant.4.Compared to DST,the sensitivity of HAIN Line Probe Assay to detection of Isoniazid(INH)was 94.33%,the specificity was 94.12%,and the kappa value was0.785.Both methods were highly consistent in judging whether INH was resistant.5.Compared with traditional DST,the sensitivity of HAIN Line Probe Assay to detect MDR was 96.97%,the specificity was 97.96%,the coincidence rate was 0.877,and the two methods have a very high degree of consistency in screening MDR-TB.6.To analyze the RIF resistance of 32 patients diagnosed as MDR-TB,it was found that the highest mutation frequency of rpoB in the region is WT8 and MUT3mutation at the same time,that is 530~533 bit codon occurred S531L mutation,which frequency was 56.25%.The second was the simultaneous mutation of WT7 and MUT2,that is,the 526~529 bit codon occurs h526y mutation,and the frequency was 15.68%.The third was WT3+WT4+MUT1 mutation,that is,the 513~519 bit codon occurs d516v mutation,which frequency was 9.38%.7.The analysis of the INH resistance of 32 patients diagnosed as MDR-TB showed that the total mutation frequency of the katG gene was 96.88%,while the total mutation frequency of the inhA gene was 37.50%.The difference is statistically significant(?2=22.12,p<0.05).It can be considered that the katG gene mutation frequency is higher than the inhA gene,and katG gene may be one of the main causes of drug resistance in the region.ConclusionIn the diagnosis of MDR-TB,the efficacy of HAIN Line Probe Assay and DST is close.And the detection time of HAIN Line Probe Assay is shorter than that of traditional drug sensitivity test.HAIN Line Probe Assay can replace traditional TB drug sensitivity test for rapid screening and early diagnosis of MDR-TB.HAIN Line Probe Assay can also be used to analyze the gene mutation of drug-resistant TB patients in the population,and to judge the resistance level of the population. |
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