Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.7.1.2 (nitrate reductase)
 3,861 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Testing the direct nitrate reductase technique versus the absolute concentration test has indicated that the former may be successfully used for rapid determination of the sensitivity of Mycobacterium tuberculosis (MBT) to isoniazid and rifampicin and it can reduce the time of obtaining a result by 4-5 times in the cases that sputum bacterioscopy yielded a positive result that allows the modified method to be applied. The advantages of the TB-Biochip technique are the time of detection multidrug-resistant MBT (24 hours), a possibility of obtaining these data just when analyzing sputum-isolated MBT DNA, and characterization of the MBT genomic elements that are responsible for drug sensitivity to antituberculous agents, by determining mutations in the examined genes and this all by using one chip. The agreement of results of microbiological and molecular genetic studies study of drug MBT sensitivity was 98%. There were no differences in the results of those using isoniazid. As for rifampicin, there was a difference in two samples (3.8%). Analysis of a combination of mutations forming multidrug resistance indicated that 74.3% of multidrug-resistant MBT isolates had mutations in the codon Ser531 > Lue of the rpoB gene and in the codon Ser315 > Thr of the katG gene. 97.4% of strains with signs of multidrug resistance had mutations in the codon 315 of the katG gene. 20.5% of isoniazid-resistant strains were observed to have mutations in two genes (katG and inhA) and 28.2% of the strains exhibited double mutation in the katG gene - Ser315Thr and Ile335 > Val.
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PMID:[Determination of multidrug resistance of M. tuberculosis by different methods]. 1688 Dec 35

The turnaround times for conventional methods used to detect Mycobacterium tuberculosis in sputum samples and to obtain drug susceptibility information are long in many developing countries, including Panama, leading to delays in appropriate treatment initiation and continued transmission in the community. We evaluated the performance of a molecular line probe assay, the Genotype MTBDRplus version 2.0 assay, in detecting M. tuberculosis complex directly in respiratory specimens from smear-positive tuberculosis cases from four different regions in Panama, as well as the most frequent mutations in genes conferring resistance to isoniazid (katG and inhA) and rifampin (rpoB). Our results were confirmed with the nitrate reductase assay and genomic sequencing. M. tuberculosis complex was detected by the Genotype MTBDRplus 2.0 assay with 100% sensitivity and specificity. The sensitivity and specificity for rifampin resistance were 100% and 100%, respectively, and those for isoniazid resistance were 90.7% and 100%. Isoniazid monoresistance was detected in 5.2% of new cases. Genotype MTBDRplus 2.0 is highly accurate in detecting M. tuberculosis complex in respiratory specimens and is able to discriminate isoniazid-monoresistant cases from multidrug-resistant cases within 2 days.
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PMID:First Evaluation of GenoType MTBDRplus 2.0 Performed Directly on Respiratory Specimens in Central America. 2744 Aug 16

INTRODUCTION Systematic surveillance of antituberculosis drug resistance allows identification of multidrug-resistant and extensively drug-resistant isolates of Mycobacterium tuberculosis. Surveillance studies of antituberculosis drug resistance systematically conducted in Cuba for over 15 years have revealed low circulation of multidrug-resistant tuberculosis, under 1% in new cases. OBJECTIVE Characterize antituberculosis drug resistance in isolates of M. tuberculosis recovered from patients with pulmonary tuberculosis in Cuba in 2012-2014. METHODS The nitrate reductase assay was used to test 997 isolates of M. tuberculosis for sensitivity to isoniazid and rifampicin. Isolates identified as multidrug resistant were tested for sensitivity to isoniazid, rifampicin, streptomycin, ethambutol, ofloxacin, amikacin, kanamycin and capreomycin by the proportion method, as well as genetic resistance mutations in rpoB, katG, inhA, gyrA, rrs and embB genes, using GenoType MTBDRplus and MTBDRsl commercial kits. RESULTS Some 95.6% of isolates from new cases and 89.6% of isolates from previously treated patients were sensitive to isoniazid and rifampicin. Multidrug resistance was found in 0.8% of new and 5.2% of previously treated patients, a statistically significant difference. One extensively drug-resistant isolate was detected among previously treated cases. All isolates examined with the molecular method had mutations in the rpoB gene, which is associated with resistance to rifampicin; only seven showed mutations in the katG gene and one in the inhA gene associated with isoniazid resistance. In one isolate, we found mutations in both gyrA and rrs genes, which are associated with resistance to fluoroquinolones and second-line injectable drugs and therefore, extensive resistance. CONCLUSIONS Results corroborate the low frequency of multidrug-resistant and extensively resistant M. tuberculosis strains in Cuba and highlight the need for continuous improvement of surveillance of antituberculosis drug resistance in Cuba. KEYWORDS Mycobacterium tuberculosis, multidrug resistance, extensively drug-resistant tuberculosis, Cuba.
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PMID:Antituberculosis Drug Resistance in Pulmonary Isolates of Mycobacterium tuberculosis, Cuba 2012-2014. 2822 40