Contributions to the diagnosis of pirazinamide resistance in Mycobacterium tuberculosis
نویسندگان
چکیده
The direct detection of pyrazinamide resistance in Mycobacterium tuberculosis is not routinely performed in many laboratories in the world because the drug is active only at acid pH, which also affects the growth of Mycobacterium tuberculosis. The pyrazinamidase enzyme, encoded by pncA gene, is necessary to convert prodrug pyrazinamide to its active form. Taking into account that nicotinamide, a structural analogue of pyrazinamide, converted in its active forms by the pyrazinamidase enzyme at a physiological pH does not affect bacterial growth, the aim of this research was to evaluate two colorimetric methods: Nitrate reductase and malachite green microtube assays, using nicotinamide to perform susceptibility testing in 102 Mycobacterium tuberculosis strains. The results were compared with those obtained by the classic Wayne assay. Mutations in the pncA gene were identified by sequencing the pncA gene from all isolates in which pyrazinamide resistance was detected by any of the three methods. Both the nitrate reductase and malachite green microtube assays showed sensitivities of 93.75% and specificities of 97.67%. Mutations in the pncA gene were found in 14 of 16 strains (87.5%) that were pyrazinamide resistant.
منابع مشابه
Evaluation of Gene Mutations Involved in Drug Resistance in Mycobacterium Tuberculosis Strains Derived from Tuberculosis Patients in Mazandaran, Iran, 2013
Drug resistance (especially multiple drug resistance) in Mycobacterium tuberculosis makes global concerns in treatment and control of tuberculosis. Rapid diagnosis of drug resistant strains of the bacteria has vital importance in the prognosis of the disease. The aim of this study was to identify the mutations responsible for drug resistance in Mycobacterium tuberculosis strains derived from pa...
متن کاملA STUDY OF MYCOBACTERIUM TUBERCULOSIS DRUG RESISTANCE IN PULMONARY TUBERCULOSIS
Tuberculosis remains a major public health problem in both developing and developed countries. Drug-resistant tuberculosis is an increasing health problem and serious challenge to tuberculosis (TB) control programs. Information about the susceptibility pattern of Mycobacterium tuberculosis isolates against anti-tuberculosis drugs is an important aspect to TB control. The objectives of the s...
متن کاملInvestigation of the rpoB Mutations Causing Rifampin Resistance by Rapid Screening in Mycobacterium Tuberculosis in North-East of Iran
Background and Objectives: The incidence of rifampin-resistant strains of Mycobacterium tuberculosis has attracted more attention than the tuberculosis infection due to laborious treatment and control. Recognizing the Mycobacterium tuberculosis genotypes involving in drug resistance via multiplex PCR, a simple and rapid genotyping method, is an emergency for better tre...
متن کاملPoint-Mutations in embB306 Gene and Their Association with Resistance to Ethambutol in Mycobacterium tuberculosis in Clinical Isolates
Background & Objective: Mutations in embB306 gene and their association with resistance to ethambutol (EMB) in Mycobacterium tuberculosis (M. tuberculosis) have not been fully investigated. The aim of this study was to investigate the point-mutations in emb306B gene and their association with resistance to EMB in M. tuberculosis. Materials & Methods: This case (M. tuberculosis resistant to EMB...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2012