Airborne Survival of Escherichia coli under Different Culture Conditions in Synthetic Wastewater

Abstract

Bioaerosol generated in wastewater treatment plants has potential to harm human health. Survival of bacteria in bioaerosol during suspension is one of the major factors that affect its biological risk. It is hypothesized that bacteria grown in different wastewater have different physiology and lead to variation in airborne survival. This study investigated the relationship between the cultured conditions and the bioaerosol survival. Synthetic wastewater was used as the culture medium to simulate the water quality of wastewater. Escherichia coli BW25113 were cultured in different conditions, including growth salinity, growth temperature, growth pH, and presence of pesticide. The fatty acid composition and the reduction in airborne survival of the E. coli cultured under these conditions were determined and compared. Results showed that increasing growth salinity and temperature led to a lower reduction in airborne survival of E. coli. E. coli cultured at pH 6 had a higher reduction in airborne survival than those cultured at pH 7 and 8. Moreover, a correlation was observed between the membrane fluidity (fluidity index) and the reduction airborne survival for both aerosolization and airborne suspension. A link between culture conditions, bacterial membrane fluidity, and airborne survival was established. Culture conditions (wastewater quality) that lead to a low membrane fluidity of bacteria increase the airborne survival of bioaerosol, and vice versa. This provides a new aspect to evaluate bioaerosol survival and improve assessment on biological risk of bioaerosols.

Associations Between Eight Earth Observation‐Derived Climate Variables and Enteropathogen Infection: An Independent Participant Data Meta‐Analysis of Surveillance Studies With Broad Spectrum Nucleic Acid Diagnostics

“…Airborne zoonotic transmission of campylobacteriosis has been documented in poultry plant workers (Wilson, 2004 ) and prevalence of household‐scale poultry husbandry is high in many of the settings represented by these data (Schiaffino et al., 2020 ; Sultana et al., 2012 ). Similarly, airborne bioaerosols are a hypothesized secondary transmission mechanism for E. coli and Cryptopsoridium (W. L. Chan et al., 2019 ; Fujiyoshi et al., 2017 ; Sponseller et al., 2014 ). Though no such route has been considered for Shigella , and associations of this pathogen with wind speed were very modest, it is a similarly sized organism to Campylobacter (both <1.0 μm wide and <6.0 μm long) suggesting that transmission via air or houseflies acting as mechanical vectors may be equally plausible for the two species (Levine & Levine, 1991 ; Murray et al., 2013 ).…”

Bioaerosol Release from Concentrated Microbial Suspensions in Bubbling Processes

“…Escherichia coli (E. coli), a gram-negative coliform bacteria, was selected as a model organism for this study based on its wide presence in the air of many occupational settings (i.e., hospitals, recycling points, wastewater treatment facilities) and its regular use in bioaerosol laboratory-based studies [25,26].…”

Survival of Escherichia coli in Airborne and Settled Poultry Litter Particles

“…To determine the survivability of airborne and settled E. coli in laboratory, a proper aerosolization method that may mimic the fate of E. coli in the commercial poultry production environment is required. The wet aerosolization method such as nebulization was widely used to study the survivability of airborne E. coli [17]. However, the airborne E. coli in poultry houses are aerosolized from dried litter by bird activities, such as dust bathing [14].…”