African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Short Communication

Rapid low-cost identification of Mycobacterium tuberculosis complex using p-nitro-benzoic acid (PNB) as inhibitor and the resazurin microplate assay (REMA): A preliminary study

Dissou Affolabi1,2, N’Dira Sanoussi1, Mathieu Odoun1, Anandi Martin2,3, Louis Koukpemedji1, Juan Carlos Palomino2, Luc Kestens4, Séverin Anagonou1 and Françoise Portaels2
1Laboratoire de Référence des Mycobactéries, Cotonou, Bénin. 2Mycobacteriology Unit, Institute of Tropical Medicine, Antwerp, Belgium. 3Médecins Sans Frontières, Paris, France. 4Immnunology Unit, Institute of Tropical Medicine, Antwerp, Belgium.
Email: [email protected]

  •  Accepted: 05 June 2013
  •  Published: 11 June 2013

Abstract

A rapid test for the differentiation of Mycobacterium tuberculosis complex from non-tuberculous mycobacteria (NTM) was developed using p-nitro-benzoic acid (PNB) as inhibitor and the resazurin microplate assay (REMA) for detection of growth. One hundred and fifty-one M. tuberculosis strains and 36 NTM were evaluated. Using a cut-off of 250 µg/ml of PNB, all M. tuberculosis strains were correctly differentiated from NTM; only two NTM strains failed to be correctly identified with this procedure. The time to obtain results was 8 days compared to 28 days or more with the conventional method. The use of REMA and PNB represents a rapid and inexpensive procedure that could be used in laboratories in low-income settings for the rapid differentiation between M. tuberculosiscomplex and NTM.

 

Key words: Mycobacterium tuberculosis, identification, resazurin.

Abbreviation

REMA, Resazurin microplate assay;TB, tuberculosis; NTM, non-tuberculous mycobacteria; PNB, p-nitrobenzoic acid; MGIT, mycobacterial growth indicator tube; MIC, minimal inhibitory concentration; MTT, 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide.