Aerosol Infection of Mice with Mycobacteria Using a Nose-Only Exposure Device

Abstract

The effectiveness of an aerosol producing system (In-Tox Products, Albuquerque, NM) commonly used for toxicological studies of chemicals and radioisotopes was evaluated for experimental tuberculosis infection of mice. Previously, experimental tuberculosis of rodents has been accomplished by aerosol infection devices which exposed the entire animal to the aerosol within a chamber. We utilized the In-Tox system to infect animals via the respiratory route with Mycobacterium bovis strain Bacille Calmette-Guerin (BCG) as a model for experimental pulmonary tuberculosis. The advantage of the device tested is that exposure to the infectious aerosol is limited to the nose of the animal. The present instrument was found to yield good implantation of mycobacteria into the lungs. The infectious load was reproducible and, with the addition of some filtration, the infectious agent was well contained within the device. Our results showed that this device is easy to operate, produces an effective experimental aerosol infection and is safe for the investigator.