Aerial transmission of mycobacteria.

The Henderson apparatus was used to expose mice to aerosols of Mycobacterium tuberculosis (H37Rv), M. kansasii (strain P1), another photochromogenic mycobacterium (P8), and two strains of nonphotochromogenic mycobacteria (T-39 and P2). Organisms were enumerated in the bacterial slurries before and after nebulization in a Collison nebulizer, in air samples from the equipment during nebulization, and in the lungs of animals killed at various intervals after exposure. A Goldberg rotating drum was used to test the ability of the organisms to survive aerial suspension. The mycobacteria withstood aerosolization and aerial suspension about equally well and were found in equivalent numbers in lungs from animals killed immediately after exposure. The numbers of organisms in lungs of animals killed three days later were approximately the same, but thereafter lung clearance rates varied considerably. By the eleventh day, the atypical mycobacteria had been reduced in numbers (with the exception of the photochromogeni...