MTSA-10, the product of the Rv3874 gene of Mycobacterium tuberculosis, elicits tuberculosis-specific, delayed-type hypersensitivity in guinea pigs

In a search for new skin test reagents specific for tuherculosis, me found that the antigen encoded by gene Rv3874 of Mycobacterium tuberculosis elici ted delayed-type hypersensitivity in M. tuberculosis-infected guinea pigs b ut not in control animals immunized with Mycobacterium bovis bacillus Calme tte-Guerin (BCG) or Mycobacterium avium. The antigen, which was named MTSA- 10 (for M, tuberculosis-specific antigen 10), is a prime candidate for a co mponent of a new tuberculin that will allow discrimination by a skin test o f latent M. tuberculosis infection from vaccination with BCG or from sensit ization with environmental, nontuberculous mycobacteria.