Specificity of IS6110-based DNA fingerprinting and diagnostic techniques for Mycobacterium tuberculosis complex

Abstract

Restriction fragment length polymorphism and hybridization of DNA extracted from Mycobacterium tuberculosis, nontuberculous mycobacteria, and nonmycobacterial species with a probe derived from IS6110 confirmed that IS6110 was specific to M. tuberculosis complex. In addition, DNA amplification with IS6110-specific primers yielded a 181-bp fragment only in DNA from M. tuberculosis complex isolates.

FIG. 1

Isolates of mycobacterial and nonmycobacterial species hybridized with the international INS1/INS2 IS6110 probe. Lane(s): M, Lambda HindIII molecular weight (size) marker; 1 and 12, M. tuberculosis Mt. 14323; 2, M. avium complex; 3, M. xenopi; 4, M. kansasii; 5, M. gordonae; 6, M. fortuitum; 7, M. chelonae; 8, M. malmoense; 9, Nocardia sp.; 10, M. marinum; and 11, E. coli NCTC 10418.

FIG. 2

Amplified products of various mycobacterial and nonmycobacterial species obtained by using IS6110 two-tube nested PCR. Lane(s): M, 100-bp ladder (Promega, Madison, Wis.); 1, M. avium complex; 2, M. xenopi; 3, M. kansasii; 4, M. gordonae; 5, M. fortuitum; 6, M. chelonae; 7, M. malmoense; 8, Nocardia sp.; 9, M. marinum; 10, E. coli NCTC 10418; 12 and 13, M. tuberculosis Mt. 14323; 15 through 21, negative controls; 23 and 24, BCG strain (Glaxo) positive controls (amplification of 0.05 and 0.5 pg of BCG DNA, respectively); 11, 14 and 22, empty. Arrows indicate the position of a 181-bp IS6110 fragment.