The Cell Membrane as a Major Site of Damage during Aerosolization ofEscherichia coli

• DOI: 10.1128/aem.01116-10
• Publication Date: 2010-12-11T04:14:54Z
• Authors: Richard J. Thomas; Daniel Webber; Rebecca Hopkins; Andrew Frost; Thomas Laws; Pramukh N. Jayase...; Timothy Atkins
• Keywords: Aerosols; 0301 basic medicine; 03 medical and health sciences; Microbial Viability; Nebulizers and Vaporizers; Cell Membrane; Colony Count, Microbial; Escherichia coli; Particle Size; Culture Media; 3. Good health

ABSTRACTThis study aimed to provide data on the survival and site of damage ofEscherichia colicells following aerosolization using two different techniques, nebulization and flow focusing. Four metabolic stains were assessed for their ability to detect respiratory activities and membrane homeostasis in aerosolizedE. colicells. The degree of sublethal injury increased significantly over the 10-min period of aerosolization inE. colicells aerosolized by using the Collison nebulizer, reaching up to 99.9% of the population. In contrast, a significantly lower proportion of the population was sublethally damaged during aerosolization using the flow-focusing aerosol generator (FFAG). Concomitantly, loss of membrane homeostasis increased at a higher rate in nebulized cells (68 to 71%) than in those aerosolized by using the FFAG (32 to 34%). The activities of respiratory enzymes decreased at increased rates in nebulized cells (27 to 37%) compared to the rates of decrease in cells aerosolized by using the FFAG (59 to 61%). The results indicate that the physiology of an aerosolized bacterium is linked to the method of aerosol generation and may affect the interpretation of a range of aerobiological phenomenon.