RDRioMycobacterium tuberculosis strains associated with isoniazid resistance in Northern Mexico.

BACKGROUND: It has been established that the genomic background of Mycobacterium tuberculosis may influence disease progression, in particular for the Beijing family and the Latin American and Mediterranean (LAM)/RDRio strains. The purpose of this study was to evaluate the prevalence of the LAM/RDRio genotype in cases of tuberculosis from Mexico and their drug susceptibility profile. METHODS: Two hundred eighteen M. tuberculosis isolates were screened by 43-spacer spoligotyping. The LAM/RDRio genotype was confirmed by multiplex PCR, and the drug susceptibility testing was carried out in solid Löwenstein-Jensen media. RESULTS: Among the LAM strains identified, 24 (63.1%) were confirmed as M. tuberculosis RDRio. All RDRio strains shared the RD174 deletion, that was associated with isoniazid resistance (p=0.0264). CONCLUSIONS: We documented for the first time the isolation of the LAM/RDRio genotype in pulmonary cases of tuberculosis in Mexico, and we found resistance to the first-line anti-tuberculosis drug isoniazid in these strains.

RDRioMycobacterium tuberculosis strains associated with isoniazid resistance in Northern Mexico / Identificación del genotipo Mycobacterium tuberculosis RDRio en el norte de México y su asociación con la resistencia a isoniazida

Background: It has been established that the genomic background of Mycobacterium tuberculosis may influence disease progression, in particular for the Beijing family and the Latin American and Mediterranean (LAM)/RDRio strains. The purpose of this study was to evaluate the prevalence of the LAM/RDRio genotype in cases of tuberculosis from Mexico and their drug susceptibility profile. Methods: Two hundred eighteen M. tuberculosis isolates were screened by 43-spacer spoligotyping. The LAM/RDRio genotype was confirmed by multiplex PCR, and the drug susceptibility testing was carried out in solid Löwenstein-Jensen media. Results: Among the LAM strains identified, 24 (63.1%) were confirmed as M. tuberculosis RDRio. All RDRio strains shared the RD174 deletion, that was associated with isoniazid resistance (p=0.0264). Conclusions: We documented for the first time the isolation of the LAM/RDRio genotype in pulmonary cases of tuberculosis in Mexico, and we found resistance to the first-line anti-tuberculosis drug isoniazid in these strains.(AU)

Introducción: El genotipo de Mycobacteriumtuberculosis podría influir en la fisiopatología y la evolución de la tuberculosis, en particular los genotipos Beijing y LAM/RDRio. El propósito de este estudio fue evaluar la prevalencia del genotipo LAM/RDRio en casos de tuberculosis pulmonar en México y determinar su perfil de sensibilidad a los fármacos antituberculosos. Métodos: Se evaluaron 218 cepas de M. tuberculosis mediante spoligotyping. El genotipo LAM/RDRio se confirmó mediante PCR múltiple. Las pruebas de sensibilidad a fármacos antituberculosos se realizaron en medio sólido de Löwenstein-Jensen. Resultados: Entre las cepas LAM identificadas, 24 (63,1%) fueron confirmadas como M. tuberculosis RDRio y se asociaron significativamente con resistencia a isoniazida (p = 0,0264). Todos los aislamientos RDRio presentaron la deleción del locus RD174. Conclusión: En este estudio documentamos por primera vez el aislamiento del genotipo RDRio en casos de tuberculosis pulmonar en México, encontrando una asociación estadísticamente significativa entre este genotipo y la resistencia a isoniazida.(AU)

RDRioMycobacterium tuberculosis strains associated with isoniazid resistance in Northern Mexico.

BACKGROUND: It has been established that the genomic background of Mycobacterium tuberculosis may influence disease progression, in particular for the Beijing family and the Latin American and Mediterranean (LAM)/RDRio strains. The purpose of this study was to evaluate the prevalence of the LAM/RDRio genotype in cases of tuberculosis from Mexico and their drug susceptibility profile. METHODS: Two hundred eighteen M. tuberculosis isolates were screened by 43-spacer spoligotyping. The LAM/RDRio genotype was confirmed by multiplex PCR, and the drug susceptibility testing was carried out in solid Löwenstein-Jensen media. RESULTS: Among the LAM strains identified, 24 (63.1%) were confirmed as M. tuberculosis RDRio. All RDRio strains shared the RD174 deletion, that was associated with isoniazid resistance (p=0.0264). CONCLUSIONS: We documented for the first time the isolation of the LAM/RDRio genotype in pulmonary cases of tuberculosis in Mexico, and we found resistance to the first-line anti-tuberculosis drug isoniazid in these strains.