| Journal: | Biotecnología aplicada |
| Database: | PERIÓDICA |
| System number: | 000348709 |
| ISSN: | 0864-4551 |
| Authors: | Montoro, Ernesto1 Lemus, Dihadenys1 Mirabal, Niuris1 Echemendía, Miguel1 Madruga, Mariela1 Milian, Yoslaine1 Díaz, Raúl1 Takiff, Howard2 Martin, Anandi3 Van der Stuyf, Patrick4 Palomino, Juan C3 |
| Institutions: | 1Instituto de Medicina Tropical "Pedro Kouri", Laboratorio Nacional de Referencia e Investigaciones en Tuberculosis y Micobacterias, La Habana. Cuba 2Instituto Venezolano de Investigaciones Científicas, Centro de Microbiología y Biología Celular, Caracas, Distrito Federal. Venezuela 3Institute of Tropical Medicine, Mycobacteriology Unit, Antwerp. Bélgica 4Institute of Tropical Medicine, Epidemiology and Disease Control Unit, Antwerp. Bélgica |
| Year: | 2011 |
| Volumen: | 28 |
| Number: | 4 |
| Pages: | 265-267 |
| Country: | Cuba |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, aplicado |
| Spanish abstract | Los estudios de susceptibilidad a PZA no se realizan de rutina debido a que el pH ácido requerido para lograr la actividad de la droga, afecta el crecimiento de Mycobacterium tuberculosis. La PZA es convertida en su forma activa por acción de la enzima pirazinamidasa (PZAasa) que es codificada por el gen pncA. Tomando en consideración que la enzima PZAasa es la responsable de convertir la nicotinamida (NIC), droga análoga de la PZA, en su forma activa sin requerir de un pH ácido, nos propusimos evaluar dos métodos colorimétricos: Método de la Nitrato Reductasa (MNR) y Microensayo Verde Malaquita (MVM) para conocer la susceptibilidad de 102 cepas de Mycocbacterium tuberculosis a la PZA empleando la NIC. Los resultados obtenidos se compararon con el Ensayo Enzimático de Wayne (método de referencia). A las cepas resistentes y las que mostraron resultados discordantes, se les secuenció el gen pncA. Se alcanzó una sensibilidad del 93.75% y una especificidad del 97.67% para el MNR y el MVM. El 87.5% de las cepas resistentes (14/16) mostraron mutaciones en el gen pncA |
| English abstract | The direct detection of pyrazinamide resistance in Mycobacterium tuberculosis is not routinely performed in many laboratories in the world because the drug is active only at acid pH, which also affects the growth of Mycobacterium tuberculosis. The pyrazinamidase enzyme, encoded by pncA gene, is necessary to convert prodrug pyrazinamide to its active form. Taking into account that nicotinamide, a structural analogue of pyrazinamide, converted in its active forms by the pyrazinamidase enzyme at a physiological pH does not affect bacterial growth, the aim of this research was to evaluate two colorimetric methods: Nitrate reductase and malachite green microtube assays, using nicotinamide to perform susceptibility testing in 102 Mycobacterium tuberculosis strains. The results were compared with those obtained by the classic Wayne assay. Mutations in the pncA gene were identified by sequencing the pncA gene from all isolates in which pyrazinamide resistance was detected by any of the three methods. Both the nitrate reductase and malachite green microtube assays showed sensitivities of 93.75% and specificities of 97.67%. Mutations in the pncA gene were found in 14 of 16 strains (87.5%) that were pyrazinamide resistant |
| Disciplines: | Medicina |
| Keyword: | Farmacología, Microbiología, Tuberculosis, Mycobacterium tuberculosis, Resistencia a fármacos, Pirazinamida |
| Keyword: | Medicine, Microbiology, Pharmacology, Tuberculosis, Mycobacterium tuberculosis, Drug resistance, Pyrazinamide |
| Full text: | Texto completo (Ver PDF) |
