title: Bacterial survival in evaporating deposited droplets on a teflon-coated surface.
abstract: Understanding of bacterial survival in aerosols is crucial for controlling infection transmission via airborne aerosols and/or large droplets routes. The cell viability changes of four bacteria species (Escherichia coli K12 JM109; Acinetobacter sp. 5A5; Pseudomonas oleovorans X5; and Staphylococcus aureus X8), three Gram-negative and one Gram-positive, in a large evaporating droplet of size 1,800 microm in diameter on teflon-coated slides were measured using the LIVE/DEAD BacLight solution and a microscope. Droplets of three levels of salinity (0, 0.9, and 36% w/v) were tested. All four species survived well during the droplet evaporation process, but died mostly at the time when droplets were dried out at 40-45 min. The final bacteria survival rate after droplets were completely dried was dependent on bacteria species and the salinity of the suspension solution. Droplet evaporation over the first 35-40 min had no adverse effect on bacterial survival for the droplets tested. The lethal effect of desiccation was found to be the most important death mechanism.
authors.affiliation: Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, People's Republic of China.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Xie
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Li
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.forename: Herbert H P
authors.initials: HH
authors.lastname: Fang
mesh_terms: D000150:Acinetobacter / Q000502:physiology; D000336:Aerosols; D001419:Bacteria; D018407:Bacterial Physiological Phenomena; D015169:Colony Count, Microbial; D003890:Desiccation; D004926:Escherichia coli / Q000502:physiology; D007700:Kinetics; D050296:Microbial Viability; D008954:Models, Biological; D011138:Polytetrafluoroethylene; D012965:Sodium Chloride / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000502:physiology; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D014871:Water Microbiology
chemical_list: D000336:Aerosols; D014867:Water; D012965:Sodium Chloride; D011138:Polytetrafluoroethylene