OBJECTIVE: To perform the analysis of specific regions of the major genes associated with resistance to isoniazid or rifampin. MATERIALS AND METHODS: Twenty two M. tuberculosis strains, isolated from human samples obtained in Sonora, Mexico. Specific primers for hotspots of the rpoB, katG, inhA genes and the ahpC-oxyR intergenic region were used. The purified PCR products were sequenced. RESULTS: Mutations in the promoter of inhA, the ahpC-oxyR region, and codon 315 of katG and in 451 or 456 codons of rpoB, were identified. CONCLUSIONS: Detection of mutations not previously reported requires further genotypic analysis of Mycobacterium tuberculosis isolates in Sonora.

OBJETIVO: Realizar el análisis de regiones específicas de genes asociados con resistencia a isoniazida o rifampicina. MATERIAL Y MÉTODOS: Se estudiaron 22 cepas de M. tuberculosis, aisladas en Sonora, México. Se utilizaron iniciadores para regiones específicas de los genes rpoB, katG e inhA y la región ahpC-oxyR. Los productos de PCR se secuenciaron y analizaron. RESULTADOS: Se identificaron mutaciones en la región promotora del gen inhA, región ahpC-oxyR, codón 315 del gen katG y codones 451 ó 456 del gen rpoB. CONCLUSIONES: La identificación de mutaciones no descritas previamente obliga a continuar el análisis genotípico de cepas aisladas en Sonora.

OBJECTIVE: To perform the analysis of specific regions of the major genes associated with resistance to isoniazid or rifampin. MATERIALS AND METHODS: Twenty two M. tuberculosis strains, isolated from human samples obtained in Sonora, Mexico. Specific primers for hotspots of the rpoB, katG, inhA genes and the ahpC-oxyR intergenic region were used. The purified PCR products were sequenced. RESULTS: Mutations in the promoter of inhA, the ahpC-oxyR region, and codon 315 of katG and in 451 or 456 codons of rpoB, were identified. CONCLUSIONS: Detection of mutations not previously reported requires further genotypic analysis of Mycobacterium tuberculosis isolates in Sonora.

OBJETIVO: Realizar el análisis de regiones específicas de genes asociados con resistencia a isoniazida o rifampicina. MATERIAL Y MÉTODOS: Se estudiaron 22 cepas de M. tuberculosis, aisladas en Sonora, México. Se utilizaron iniciadores para regiones específicas de los genes rpoB, katG e inhA y la región ahpC-oxyR. Los productos de PCR se secuenciaron y analizaron. RESULTADOS: Se identificaron mutaciones en la región promotora del gen inhA, región ahpC-oxyR, codón 315 del gen katG y codones 451 ó 456 del gen rpoB. CONCLUSIONES: La identificación de mutaciones no descritas previamente obliga a continuar el análisis genotípico de cepas aisladas en Sonora.