Detecção de mutações no gene rpoBeta associadas a Mycobacterium tuberculosis resistentes a rifampicina

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Isoniazid, rifampin, and pyrazinamide, have been used as the standard treatment for tuberculosis in many countries, including Brazil. Antimicrobial resistance among Mycobacterium tuberculosis strains results in increased morbidity, mortality and costs of health care. Control of tuberculosis is thus threatened by widespread emergence of drug resistance in Mycobacterium tuberculosis as reported worldwide. Mutations in the rpo? gene seems to be the most prevalent mechanism involved in rifampin resistance among M. tuberculosis strains. To characterize the genetic basis of drug resistance in Mycobacterium tuberculosis in Brazil, mutations involved in rifampin resistance were detected using single strand conformation polymorphism (SSCP) and sequencing studies. A sample consisting of 73 isoniazid resistant and 5 isoniazid sensitive isolates recovered from August, 1999 through September, 2000 was screened for susceptibility to rifampin. As a result, 13 susceptible, and 65 resistant strains were detected. Genomic DNA was obtained from each isolate, and a fragment consisting of 157 bp of the rpo? gene was amplified, and submitted to SSCP and sequencing studies. Mutations involving codon 511 through codon 533 were identified. S531L (44%) was the most prevalent mutation found, followed by H526D (21%), and H526Y, L533P, D516V, Ins Phe514, Met515 (3% each). Our study corroborates previous studies done in Brazil which identified S531L as the most prevalent mutation, and several other mutations on the same gene segment (codon 511 through 533)

ASSUNTO(S)

tuberculose micobacterias mutação (biologia)

ACESSO AO ARTIGO

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