Effect of different pathways on establishment of experimental tuberculosis in SD rats

Abstract

Objective To develop SD rat model of Mycobacterium tuberculosis infection and to compare different routes of infection in animal model. Methods 60 SD rats were randomly divided into four groups. The rats were respectively injected with 0.01 mg standard strain of Mycobacterium tuberculosis H37Rv through the right side of the chest, abdomen, tail vein, and the tail skin. At the eighth week after injection, the rats were killed to observe the gross lesions and pathological changes of lung, liver, spleen and delayed hypersensitivity at the injection site. The lung tissue smear was used to observe the growth of Mycobacterium tuberculosis by acid-fast staining and cultivation. Results The lung, liver,and spleen showed different degrees of tuberculous inflammatory changes by HE staining. The lung tissue showed different number of short, red dye Mycobacterium by acid-fast staining. Compared with groups of injection in abdomen and tail skin,the pathological changes of chest were more typical and the positive rate of tissue culture was higher in groups of injection in chest and tail vein. The tuberculosis changes of liver and spleen in group of intraperitoneal injection were more significant than those in other groups. Conclusions SD rats are sensitive to Mycobacterium tuberculosis. The injection of Mycobacterium tuberculosis by chest, abdomen,and tail vein can establish the rat model of Mycobacterium tuberculosis infection. In addition, the injection of Mycobacterium tuberculosis by chest, abdomen, and tail vein are respectively fit for the establishment of tuberculous pleurisy, abdominal tuberculosis, and tuberculosis model, the injection in tail skin is generally only used to produce immunity. Key words: SD rats; Tuberculosis; Mycobacterium tuberculosis; Animal models