Department of Biology
Other than the needs for infection control to investigate the survival and inactivation of airborne bacterial pathogens, there has been a growing interest in exploring bacterial communities in the air and the effect of environmental variables on them. However, the innate biological mechanism influencing the bacterial viability is still unclear. In this study, a mutant-based approach, using Escherichia coli as a model, was used to prove the concept that common stress-response genes are important for airborne survival of bacteria. Mutants with a single gene knockout that are known to respond to general stress (rpoS) and oxidative stress (oxyR, soxR) were selected in the study. Low relative humidity (RH), 30–40% was more detrimental to the bacteria than high RH, >90%. The log reduction of ∆rpoS was always higher than that of the parental strain at all RH levels but the ∆oxyR had a higher log reduction than the parental strain at intermediate RH only. ∆soxR had the same viability compared to the parental strain at all RH levels. The results hint that although different types and levels of stress are produced under different RH conditions, stress-response genes always play a role in the bacterial viability. This study is the first reporting the association between stress-response genes and viability of airborne bacteria.
Bioaerosols, Airborne bacteria, Relative humidity, Stress response
Source Publication Title
This work is licensed under the Creative Commons Attribution License 4.0.
This study was funded by the Hong Kong University Grant Council (Ref: GRF 12218416). The funding body has no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.
Link to Publisher's Edition
Ng, T., Chan, W., & Lai, K. (2017). Importance of stress-response genes to the survival of airborne Escherichia coli under different levels of relative humidity. AMB Express, 7, 71. https://doi.org/10.1186/s13568-017-0376-3