title: The cell membrane as a major site of damage during aerosolization of Escherichia coli.
abstract: This study aimed to provide data on the survival and site of damage of Escherichia coli cells 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 aerosolized E. coli cells. The degree of sublethal injury increased significantly over the 10-min period of aerosolization in E. coli cells 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.
authors.affiliation: Defence Science & Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom. rjthomas@dstl.gov.uk
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Thomas
authors.forename: Daniel
authors.initials: D
authors.lastname: Webber
authors.forename: Rebecca
authors.initials: R
authors.lastname: Hopkins
authors.forename: Andrew
authors.initials: A
authors.lastname: Frost
authors.forename: Thomas
authors.initials: T
authors.lastname: Laws
authors.forename: Pramukh N
authors.initials: PN
authors.lastname: Jayasekera
authors.forename: Timothy
authors.initials: T
authors.lastname: Atkins
mesh_terms: D000336:Aerosols; D002462:Cell Membrane / Q000502:physiology*; D015169:Colony Count, Microbial; D003470:Culture Media; D004926:Escherichia coli / Q000254:growth & development* / Q000502:physiology*; D050296:Microbial Viability; D009330:Nebulizers and Vaporizers; D010316:Particle Size
chemical_list: D000336:Aerosols; D003470:Culture Media