While many natural and artificial surfaces may appear dry, they are in fact covered by thin liquid films and microdroplets invisible to the naked eye, known as microscopic surface wetness (MSW). Central to the formation and retention of MSW are the deliquescent properties of hygroscopic salts that prevent complete drying of wet surfaces, or that drive the absorption of water until dissolution when the relative humidity is above a salt-specific level. As salts are ubiquitous, MSW occurs in many microbial habitats including soil, rocks, plant leaf surfaces, and surfaces in the indoor environments.
While key properties of MSW, including very high salinity and segregation into droplets, greatly affect microbial life therein, it has been scarcely studied, and systematic studies are only in their beginnings. The factors that determine the survival of microorganisms – including bacteria and viruses – in such microdroplets are not fully understood.
In this talk Dr. Nadav Kashtan of the Kasktan Lab provides an overview of these microdroplets and how we can detect bacteria and viruses in such microdroplets environments deposited on surfaces using microscopy imaging techniques. What is also very important is assessing virus viability which is also discussed. Finally, Dr. Kashan presents the results of their recent study on the survival of the enveloped bacteriophage Phi6 (a surrogate for SARS-CoV-2) in evaporated saliva microdroplets and discuss their implications for coronavirus transmission and the COVID-19 pandemic.
This presentation was part of the Andor Virology Virtual Conference March 2021.