Abstract: Objective  To study skin test with Mycobacterium tuberculosis recombinant ESAT6-CFP10 protein in Guinea pigs sensitized with several clinical common pathogenic mycobacteria and environmental mycobacteria.   Methods  Guinea pigs were infected by subcutaneous inguinal injection with 16 kinds of live mycobacterial liquids, respectively. There were 5 Guinea pigs each group. After 3 to 4 weeks, the Guinea pigs were injected intradermally with 0.1 ml of TB-PPD, PPD-B and the recombinant protein ESAT6-CFP10, respectively. The longitudinal and transverse diameters of local indurations were observed at 24 h and 48 h after the injection. The skin test were determined as positive result when average diameter was ≥5 mm at 48 h after the injection.  Results  In PPD-B group, the skin tests of Guinea pigs sensitized with 16 kinds of mycobacteria were all positive. In TB-PPD group, the skin tests of Guinea pigs sensitized with M. tuberculosis, M. bovis, M. africanum, M. bovis BCG were also positive. In ESAT6-CFP10 group, the skin tests of Guinea pigs sensitized with M. tuberculosis, M. bovis and M. africanum were positive, other Guinea pigs sensitized were negative.  Conclusion  Mycobacterium tuberculosis recombinant ESAT6-CFP10 protein can improve the specificity of Mycobacterium tuberculosis infection diagnosis.

Key words: Mycobacteria,atgpical, Skin test, Recombinant fusion proteins, Bacterial proteins