Abstract: Objective In order to establish the aerosol bacteria delivery method applied to the animal model of Pulmonary infection, a non-toxic fast-growing Mycobacterium smegmatis was used as a model bacteria and the effects, influence factors and safety about this technology was investigated.Method The C57BL/6J mice were infected by mycobacterium smegmatis at a series of dose levels (10⁶～108 CFU) and duration (30-90 min), an auto aerosol delivery device were used for aerosol bacteria preparation and infection procedure. After infectionL samples from lung tissue and skin of infected mice as well as samples from surface of the device were obtained and then cultured for bacteria amount counting by CFU method. Result The standard curve of bacteria amount-dose level and bacteria amount-infection duration were respectively set up. Existence of residual bacteria in device surface and skin of the animals was indicated by bacteria amount counting results (less than 10 CFU). Conclusion The bacteria amount in mice' lung tissue is directly and positively correlated to the dose level of aerosol bacteria and infection duration and existence of residual bacteria points out potential bio-hazard risk.

Key words: Inhalation, Mycobacterium smegmatis, Conditions ；Exploration