No abstract

The presence of mutations in specific regions of the katG, inhA, and ahpC genes was analyzed with 69 Mycobacterium tuberculosis isoniazid-resistant isolates from three Brazilian states. Point mutations in codon 315 of the katG gene were observed in 87.1, 60.9, and 60% of the isolates from Rio Grande do Sul, Rio de Janeiro, and São Paulo, respectively. Mutations in the inhA gene were identified only in one isolate from RJ State, and the ahpC promoter region revealed mutations in distinct positions in 12.9, 21.7, and 6.7% of the isolates from RS, RJ and SP, respectively.

Mutations in a 69-bp region of the rpoB gene associated with rifampin resistance (Rifr) in 100 isolates (82 Rifr) from three states of Brazil were studied. Twenty-one different kinds of mutations were identified in the Rifrisolates, and six new alleles are described.