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Objective To analyse the sensitivity ,specificity and coincidence rate of genechip method in the detection of resistance to antibacterial agents in Mycobacterium tuberculosis(MTB) ,in order to provide a convenient ,accurate and rapid method for detec‐ting antibacterial resistance in MTB .Methods The DNA sequencing was taken as gold standard ,and antibacterial resistance of the strains of MTB isolated from sputum specimens of 250 cases of patients with tuberculosis from August to December 2014 were de‐tected by using the genechip method and proportion method for susceptibility testing at the same time .Efficacies of the two methods in detecting MTB resistance to rifarnpin and isoniazid were compared .Results The MTB resistance rate to rifarnpin detected by u‐sing the genechip method and proportion method for susceptibility testing was 3 .0% and 3 .5% respectively ;that to isoniazid was 6 .7% and 8 .2% respectively .For detecting M TB resistance to rifarnpin and isoniazid ,the DNA sequencing was taken as gold standard ,the sensitivity ,specificity and coincidence rate of genechip method was higher than those of proportion method for suscep‐tibility testing ,and the test time of genechip method was shorter than that of proportion method for susceptibility testing ,there were statistically significant differences(P<0 .05) .Conclusion Using the genechip method to detecting MTB resistance to rifampin and isoniazid has high sensitivity ,specificity and coincidence rate ,which could replace the proportion method for susceptibility tes‐ting and become an effective method .
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Aim: To evaluate the methodology of MTT tube assay and compare it with standard proportion method for detection of drug susceptibility of M. tuberculosis to rifampicin (RIF) and isoniazid (INH). Study Design: Prospective. Place and Duration of Study: Sher-i-Kashmir Institute of Medical Sciences, Kashmir, India. One year study. Methodology: MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay was performed on 60 clinical isolates of M. tuberculosis. An inoculum of 107CFU/ml prepared in Middlebrook 7H9 with OADC (Oleic acid, albumin, dextrose and catalase) was chosen as standard. For each drug three tubes were used, one drug containing (INH 0.2 μg/ml or RIF 1 μg/ml), second inoculum control and third blank control. The method was performed after incubating the tubes at 37°C for 4 days for RIF and 7 days for INH. Results were read visually and by spectrophotometer at 570 nm. Relative optical density units of 0.2, was taken as cutoff. Results of drug susceptibility were compared with those obtained by Lowenstein Jensen proportion method. Results: For RIF, sensitivity was 88.9% and 94.4%; specificity was 100% and 97.6% for visual MTT and MTT by RODU respectively. For INH similar sensitivity of 95.1% was seen while specificity was 97.0% and 95.0% by visual MTT and MTT by RODU respectively. There was almost perfect agreement between proportion and MTT method for both drugs. Turn-around time for MTT assay was 7 days. Conclusion: The MTT tube assay can be used for rapid drug susceptibility testing of M. tuberculosis to RIF and INH.
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Background and Objectives: Antimycobacterial susceptibility tests take weeks, and delayed therapy can lead to spread of Mycobacterium tuberculosis. Therefore, rapid, accurate and cost-effective methods are required for proper therapy selection. In this study, the Mycobacteria growth indicator tube (MGIT) and epsilometer test (Etest) methods were compared to the agar proportion method for susceptibility testing of Mycobacterium tuberculosis. Materials and Methods: The susceptibility tests against isoniazid (INH), rifampin (RIF), streptomycin (STM) and ethambutol (ETM) of 51 M. tuberculosis complex isolates were analyzed by the MGIT, Etest and agar proportion methods. Results: The concordance between MGIT/Etest and agar proportion methods was 98% for INH and 100% for RIF, STM, ETM. There were not statistically significant differences in results of the susceptibility tests between MGIT/Etest and the reference agar proportion method. Conclusion: The results have shown that MGIT and Etest methods can be used instead of the agar proportion method, because these two methods are more rapid and easier than the agar proportion method.
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Objective To evaluate the BacT/ALERT 3D liquid culture technology on the detection of drug resistance of Mycobacterium tuberculosis(MTB)and to compare the difference between this technology and Lowenstein -Jensen (L -J) proportion method.Methods BacT/ALERT 3D liquid culture technology and L -J proportion technology were applied to detect the drug resistance of tuberculosis from the positive cultures of 219 solid culture samples.Results The average detection time of BacT/ALERT 3D method was 8.02 ±3.85 d,which was about 20 days shorter than that of L -J proportion method.60 drug resistance strains were found using BacT/ALERT 3D technology,While 79 drug resistance strains were found using L -J proportion technology.There showed no significant difference (P >0.05).The compliance rate of BacT/ALERT 3D method and L -J proportion method on the anti -tuberculosis drugs INH,RFP,EMB and SMwas 95.43%,92.69%,95.43% and 92.24% respectively.Conclusion BacT/ALERT 3D liquid culture technology could detect drug resistant TB strains rapidly with high concordance with the results of L -J proportion method on anti -tuberculosis drugs.
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Background: The emergence of XDR –TB strains is a major roadblock in the successful implementation of TB control programmes. This further leads to high morbidity and mortality, especially in immuno-compromised patients. Identification and observation of resistance patterns of XDR-TB strains may help clinicians manage MDR-TB cases, the treatment line of which is expensive, time-taking and involves intake of toxic drugs with many side-effects. Our study is aimed to find out the prevalence of XDR-TB among the MDR-TB strains isolated in a tertiary care hospital. Material & Methods: The study population consisted of 223 patients of tuberculosis who were culture positive and Mycobacterium tuberculosis was resistant to Rifampicin and Isoniazid during January 2007 to December 2009. Each patient had submitted two sputum samples i.e. spot and morning. The identified Mycobacterium tuberculosis complex was subjected to drug sensitivity testing by first and second line drugs by proportion and absolute concentration methods as per standard procedure . Results : The results showed that 20.17% strains (45/223) were XDR-TB strains. Most of these strains showed resistance to four drug combination viz. KM, ETH, OFX & PAS (5.82%), KM & OFX (3.13%), OFX, KM and ETH (1.79%), 1.34% strains showed resistance to all the drugs i.e. pan resistance and other combinations in the remaining strains. Nearly 80% of the XDR-TB strains showed resistance to three or more drugs combination pattern. Conclusion: The multidrug resistant TB cases need urgent and timely sensitivity report for second line ATT drugs to help clinicians start proper drug combinations to treat MDR-TB patients.
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Objectives: Traditional drug susceptibility testing for Mycobacterium tuberculosis takes weeks and/or expensive. In this study, we evaluated nitrate reductase assay for drug susceptibility testing which is faster than the visual detection of colonies. Materials and Methods: 32 clinical specimens (direct microscopy positive for AFB with 1+, 2+ or 3+ grading) were decontaminated and the sediment was inoculated onto the L-J medium with INH or Rifampicin incorporated with Potassium nitrate and the same medium without antibiotics at 1;10 dilution as control. After 2 weeks, the control was first tested for color change with addition of nitrate reductase reagents. If found positive, the media with antibiotics were tested and compared. Futher incubation was done if the control was found to be negative. The results obtained was compared with standard direct proportion method for drug susceptibility testing. Results: Resistance of isolates as shown by both methods for INH and Rifampicin was 37.5% and 31.3% respectively. The results showed that NRA and proportion method do not differ significantly ( P < 0.05 for both drugs). Thus an excellent agreement between the results of NRA and proportion method was found for two primary anti-tubercular drugs, 87.5% for INH and 97% for Rifampicin. Conclusion: Nitrate reductase assay is a rapid and inexpensive method for susceptibility testing of M. tuberculosis for primary anti-tubercular drugs and could be an alternative to existing methods, particularly in resource poor settings.
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Objective Through investigating the situation of health care resources in Shanghai ,from the point of population and geographical area distribution, the article analyze the fair allocation of medical resources in Shanghai to provide the basis of decision-making in rational allocation of medical resources. Methods Use Lorenz curve and the Gini coefficient indicators, as well as Chain Proportion Method. Results The allocation of medical resources in population of Shanghai is fairly,and the trend of fairness will be enhanced. In the geographical allocation in space is more unfairness in Shanghai,and the fairness will be reduced. Conclusion The allocation of medical resources Municipal Population has few gap between urban and rural areas in the Shanghai which reached a fair comparison, but in the geographic distribution of has a larger gap between urban and rural areas. Most of the medical resources concentrated in large hospitals in the urban centers. The distribution of Medical resources should be rational and the health service system should be improved to improve medical and health service accessibility.