Rapid susceptibility testing of Mycobacterium tuberculosis by the Mycobacteria Growth Indicator Tube (MGIT AST SIRE)

Authors

  • E.A. Macondo,

    1. 1 Laboratoire de Bactériologie-Virologie du CHU Aristide Le Dantec de Dakar, 2BIO-24 Laboratoire d'Analyzes de Biologie Médicale, 3Programme National de Lutte Contre la Tuberculose du Sénégal, 4Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
    Search for more papers by this author
  • 1,2 F. Ba,

    1. 1 Laboratoire de Bactériologie-Virologie du CHU Aristide Le Dantec de Dakar, 2BIO-24 Laboratoire d'Analyzes de Biologie Médicale, 3Programme National de Lutte Contre la Tuberculose du Sénégal, 4Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
    Search for more papers by this author
  • 3 A. Gaye-Diallo,

    1. 1 Laboratoire de Bactériologie-Virologie du CHU Aristide Le Dantec de Dakar, 2BIO-24 Laboratoire d'Analyzes de Biologie Médicale, 3Programme National de Lutte Contre la Tuberculose du Sénégal, 4Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
    Search for more papers by this author
  • 1,4 N.C. Touré-Kane,

    1. 1 Laboratoire de Bactériologie-Virologie du CHU Aristide Le Dantec de Dakar, 2BIO-24 Laboratoire d'Analyzes de Biologie Médicale, 3Programme National de Lutte Contre la Tuberculose du Sénégal, 4Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
    Search for more papers by this author
  • 1,4 O. Kaı¨ré,

    1. 1 Laboratoire de Bactériologie-Virologie du CHU Aristide Le Dantec de Dakar, 2BIO-24 Laboratoire d'Analyzes de Biologie Médicale, 3Programme National de Lutte Contre la Tuberculose du Sénégal, 4Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
    Search for more papers by this author
  • 1 A. Gueye-Ndiaye,

    1. 1 Laboratoire de Bactériologie-Virologie du CHU Aristide Le Dantec de Dakar, 2BIO-24 Laboratoire d'Analyzes de Biologie Médicale, 3Programme National de Lutte Contre la Tuberculose du Sénégal, 4Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
    Search for more papers by this author
  • 1 C.S. Boye,

    1. 1 Laboratoire de Bactériologie-Virologie du CHU Aristide Le Dantec de Dakar, 2BIO-24 Laboratoire d'Analyzes de Biologie Médicale, 3Programme National de Lutte Contre la Tuberculose du Sénégal, 4Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
    Search for more papers by this author
  • and 1,4 S. Mboup 1,4

    1. 1 Laboratoire de Bactériologie-Virologie du CHU Aristide Le Dantec de Dakar, 2BIO-24 Laboratoire d'Analyzes de Biologie Médicale, 3Programme National de Lutte Contre la Tuberculose du Sénégal, 4Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
    Search for more papers by this author

Corresponding author and reprint requests: M. Souleymane, Laboratoire de Bactériologie-Virologie, Faculté de Médecine et de Pharmacie, CHU A. Le Dantec de Dakar, BP 7325 Dakar-Sénégal
Tel: + 221 822 59 19/821 64 20 Fax: + 221 821 64 42
E-mail: virus@sonatel.senet.net

Abstract

Objective  To evaluate the reliability of the Mycobacteria Growth Indicator Tube (MGIT AST) for susceptibility testing of Mycobacterium tuberculosis.

Methods  Seventy strains of M. tuberculosis were tested for susceptibility to streptomycin, isoniazid, rifampicin and ethambutol by comparing MGIT AST results to those obtained by the method of proportion (MOP) on Lowenstein–Jensen (LJ) and Middlebrook 7H10 media. The 7H10 MOP was considered the method of reference.

Results  The turnaround time for MGIT AST was 6.2 days (5–10 days) and for MOP it was 18–21 days. With rifampicin, MGIT AST agreed for all isolates with both MOP. For streptomycin, MGIT AST and 7H10 MOP agreed for 64 isolates (91.4%); 61 were susceptible and three resistant. LJ MOP and 7H10 MOP agreed for 64 isolates (92.2%); 62 were susceptible and three resistant. With isoniazid, both MOP agreed for all isolates, while MGIT AST and 7H10 MOP had two discrepancies. For ethambutol, MGIT AST and 7H10 MOP were concordant for 66 isolates; 65 were susceptible and one resistant. Both MOP were concordant for 67 isolates; 66 were susceptible and one resistant.

Conclusions  Based on these results, MGIT AST is a time-saving method and can be used as an alternative to the BACTEC System. MGIT AST is reliable as far as rifampicin and isoniazid are concerned; however, additional studies are needed for streptomycin and ethambutol.

Ancillary