Therapeutic effect of bacteriophage D29 in the treatment for guinea pigs infected with sensitive strain of Mycobacterium tuberculosis

To observe the therapeutic effect of bacteriophage D29 on tuberculosis and to evaluate the possibility of its use as a tuberculostatic agent,guinea pigs infected with sensitive strain of Mycobacterium tuberculosis were randomly divided into 3 groups,i.e. control group (without use of phage),rifampin-treated group and phage-treated group. Rifampin in a dose of 25 mg/kg body weight was administrated through gastro-esophagus route and 106 PFU/0.1 mL of bacteriophage D29 was given intranasally with an interval of three times per week. In every groups of experiment,4-5 guinea pigs were sacrificed 4 weeks after treatment and the degree of gross lesions in internal organ,organ weight indices and pathological changes in various organs were observed. In addition,quantitative cultivation of M.tuberculosis was performed. It was demonstrated that the gross lesions in various organs of guinea pigs infected with M.tuberculosis treated with phage and rifampin,bacteria-bearing quantity in lungs of the phage-treated group,and that of the rifampin-treated group were significantly reduced in comparison with those of the control group (P0.01). On histopathological examination,fibrosis of lung tissues was demonstrated and some caseous necrosis could be found in spleen of the phage-treated group; while,in the control group. large amount of Langhans cells in lung tissues,mainly in the proliferative nodules,as well as many caseous necrosis in spleen were found. It is evident that the therapeutic effect of treatment with bacteriophage D29 may approach or even better than that of rifampin without any side effect to guinea pigs. So,it may be a novel and hopeful strategy to combat with tuberculosis.