Memorias do Instituto Oswaldo Cruz (Feb 2012)

Comparative evaluation under routine conditions of the nitrate reduction assay, the proportion assay and the MGIT 960 assay for drug susceptibility testing of clinical isolates of Mycobacterium tuberculosis

  • Leila de Souza Fonseca,
  • Gisele Betzler de Oliveira Vieira,
  • Luciana Fonseca Sobral,
  • Elizabete Oliveira Ribeiro,
  • Anna Grazia Marsico

DOI
https://doi.org/10.1590/S0074-02762012000100021
Journal volume & issue
Vol. 107, no. 1
pp. 142 – 144

Abstract

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The performance of the nitrate reductase assay (NRA) was compared with the proportion method (PM) on Lowenstein-Jensen medium and the BACTEC MGIT960 assay under routine conditions using 160 clinical isolates of Mycobacterium tuberculosis with a high proportion of resistant strains. The mean time to obtain results was 8.8 days and the overall agreements between NRA and PM and NRA and M960 were 95% and 94%, respectively. NRA was easy to perform and represents a useful tool for the rapid screening of drug-resistant M. tuberculosis strains in low-resource countries.

Keywords