RESUMO
A new mutation in mabA, Thr4Ile, was identified in a Mycobacterium tuberculosis isolate from a patient whose culture remained positive after treatment. The same mutation was found in another 5 patients infected by different strains. A putative role for this mutation in the process of diminishing susceptibility to isoniazid is evaluated.
Assuntos
3-Oxoacil-(Proteína Carreadora de Acil) Redutase/genética , Antituberculosos/farmacologia , Isoniazida/farmacologia , Mutação , Mycobacterium tuberculosis/genética , 3-Oxoacil-(Proteína Carreadora de Acil) Redutase/fisiologia , Antituberculosos/uso terapêutico , Sequência de Bases , Farmacorresistência Bacteriana/genética , Humanos , Isoniazida/uso terapêutico , Masculino , Testes de Sensibilidade Microbiana/métodos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/enzimologia , Alinhamento de Sequência , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologiaRESUMO
Our study provides an alert regarding the transmission of rifampin-susceptible strains of Mycobacterium tuberculosis with a silent substitution in codon 514 of rpoB. Among 1,450 cases, we identified 12 isolates sharing this mutation and related restriction fragment length polymorphism (RFLP) types. The mutation impaired hybridization with the wild-type probes in three independent commercial assays, which could lead to misassignment of resistance.
