Establishment of Tuberculosis Meningitis Mouse Model Using Aerosol Route ofW. BeijingHN878 strain

In this study, we report the development of a tuberculosis meningitis (TBM) mouse model using the HN878 strain via the aerosol route. Three genetically different strains of mice, CB6F1, C57BL/6 and BALB/c mice, were used to determine the dissemination of HN878 in the brain. The 8 x 10 8 CFU/ml of HN878 dose was used to infect CB6F1 mice and deposited approximately 3.8 (0.07, SD) log 10 CFU in the lungs. The burden of HN878 in the brain of the control group (administered saline) after approximately 16/17 days post-infection for CB6F1, C57BL/6 and BALB/c were 4.00 (0.47 SD), 3.79 (0.27, SD) and 2.12 (0.41, SD) log 10 CFU/brain, respectively. The log 10 CFU/brain in the BCG vaccinated CB6F1, C57BL/6 and BALB/c mice were 1.05 (0.61, SD), 2.13 (0.33, SD) and 1.42 (0.38, SD) respectively, which, if compared to the control groups, BCG vaccinated mice inhibited dissemination of HN878 in the brain by an impressive 2.94 (CB6F1), 1.66 (C57BL/6) and 0.69 (BALB/c) log 10 CFU/brain reduction. In conclusion, we have established a relatively inexpensive TBM mouse model using an aerosol, a natural route of infection, which will advance research in understanding TBM dissemination to the brain, and preclinical tuberculosis vaccine/drug discovery/drug regimens against TBM.