Mycobacterium Tuberculosis Infection in Rhesus Monkeys (Macaca mulatta) and Evaluation of ESAT-6 and CFP10 as Immunodiagnostic Antigens

Tuberculosis (TB) in nonhuman primates is a serious menace to the welfare of the animals and human who come into contact with them, while the rapid, accurate, and robust diagnosis is challenging. In this study, we first sought to establish an appropriate primate TB model resembling natural TB in nonhuman primates. Four rhesus monkeys (Macaca mulatta) of Chinese origin were infected intratracheally with two low doses of M. tuberculosis H37Rv. Regardless of the infectious doses, all monkeys were demonstrated to be successfully infected by clinical assessments, tuberculin skin test conversions, peripheral immune responses, gross observations, histopathology analysis, and M. tuberculosis burdens. Furthermore, we extended the usefulness of this model for assessing the following immunodiagnostic antigens: CFP10, ESAT-6, CFP10-ESAT-6, and an antigen cocktail of CFP10 and ESAT-6. The data showed that CFP10 was an M. tuberculosis-specific, "early" antigen used for serodiagnosis of TB in nonhuman primates. In conclusion, we established a useful primate TB model depending on low doses of M. tuberculosis and affording new opportunities for studies of M. tuberculosis disease and diagnostics.