Objective   To evaluate the effects of recombinant BCG vaccine encoding murine Ipr1 on Mycobacterium tuberculosis infection in rats.    Methods   Thirty BALB/c mice were randomized into 3 groups which were intranasally given PBS

BCG and recombinant BCG respectively. Two weeks later

the 3 groups were infected with Mycobacterium tuberculosis and were intranasally treated with PBS

BCG

recombinant BCG for once per 3 d

7 times totally respectively. The mice were sacrificed after the final treatment. The viable quantity of bacteria in the lungs and the spleens was detected. The weight indexes of the lungs and the spleens were calculated. ELISA was used to detect the levels of IL-10

TNF-α and IFN-γ in the serum. The expression of Ipr1 in lung and spleen tissues was detected by immunohistochemistry. Lungs and spleens were prepared for pathological analysis.    Results   In the recombinant BCG group

significant reduce was observed in number of colony forming units and weight indexes of lungs and spleens compared with the PBS group and the BCG group in the same murine strain. The level of IFN-γ was significantly increased in the recombinant BCG group compared with the other 2 groups. The expression of Ipr1 in the tissues was found in the recombinant BCG group. The pathological changes in lungs of the recombinant BCG group and the BCG group were localized

while those in the PBS group were extensive. There was no significant changes in the spleen of all groups．   Conclusion   The recombinant BCG encoding murine Ipr1 has therapeutic effects on murine Mycobacterium tuberculosis infection.