Susceptibility of Mycobacterium tuberculosis to first-line antimycobacterial agents in a Brazilian hospital: assessing the utility of the tetrazolium (MTT) microplate assay
Mem. Inst. Oswaldo Cruz
; 105(5): 661-664, Aug. 2010. tab
Article
em En
| LILACS
| ID: lil-557226
Biblioteca responsável:
BR1.1
ABSTRACT
We conducted a cross-sectional, hospital-based study between January 2006-March 2008 to estimate the resistance of Mycobacterium tuberculosis to first-line drugs in patients with tuberculosis at a Brazilian hospital. We evaluated the performance of the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] (MTT) microplate assay compared with the Bactec-MGIT 960 system for mycobacteria testing. The prevalence of resistance in M. tuberculosis was 6.7 percent. Multidrug-resistance [resistance to rifampicin (RMP) and isoniazid (INH)], INH-resistance and streptomycin (SM)-resistance accounted for 1 percent, 3.8 percent and 3.8 percent of all resistance, respectively, and all isolates were susceptible to ethambutol (EM). The resistance was primary in four cases and acquired in three cases and previous treatment was associated with resistance (p = 0.0129). Among the 119 M. tuberculosis isolates, complete concordance of the results for INH and EM was observed between the MTT microplate and Bactec-MGIT 960TM methods. The observed agreement for RMP was 99 percent (sensitivity 90 percent) and 95.8 percent for SM (sensitivity 90.9 percent), lower than those for other drugs. The MTT colourimetric method is an accurate, simple and low-cost alternative in settings with limited resources.
Palavras-chave
Texto completo:
1
Base de dados:
LILACS
Assunto principal:
Sais de Tetrazólio
/
Tiazóis
/
Tuberculose
/
Testes de Sensibilidade Microbiana
/
Corantes
/
Antibacterianos
/
Mycobacterium tuberculosis
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Brasil