Impacts of indoor surface finishes on bacterial viability

Abstract

Microbes in indoor environments are constantly being exposed to antimicrobial surface finishes. Many are rendered non‐viable after spending extended periods of time under low‐moisture, low‐nutrient surface conditions, regardless of whether those surfaces have been amended with antimicrobial chemicals. However, some microorganisms remain viable even after prolonged exposure to these hostile conditions. Work with specific model pathogens makes it difficult to draw general conclusions about how chemical and physical properties of surfaces affect microbes. Here, we explore the survival of a synthetic community of non‐model microorganisms isolated from built environments following exposure to three chemically and physically distinct surface finishes. Our findings demonstrated the differences in bacterial survival associated with three chemically and physically distinct materials. Alkaline clay surfaces select for an alkaliphilic bacterium, Kocuria rosea, whereas acidic mold‐resistant paint favors Bacillus timonensis, a Gram‐negative spore‐forming bacterium that also survives on antimicrobial surfaces after 24 hours of exposure. Additionally, antibiotic‐resistant Pantoea allii did not exhibit prolonged retention on antimicrobial surfaces. Our controlled microcosm experiment integrates measurement of indoor chemistry and microbiology to elucidate the complex biochemical interactions that influence the indoor microbiome.

Microbial Exchange via Fomites and Implications for Human Health

“…On indoor surfaces that lack abundant moisture and nutrient availability, most microorganisms that arrive from other environments (such as from human occupants) are generally considered unlikely to survive, and those viable microbes that do survive are generally considered to be inactive or dormant until transferred to other host locations or until they experience an influx of moisture and nutrients that help them proliferate [4••, [50][51][52]. Surveys of fungal communities in indoor environments, conducted using high-throughput molecular sequencing, have shown that they tend to be driven primarily by transport from the local outdoor environment [31].…”

Mobilizable antibiotic resistance genes are present in dust microbial communities

“…It is one of relatively few clades near-universally prevalent on human skin as a commensal, and as a result is widely distributed in the built environment; it can also drive significant opportunistic infection [68]. In fact, the clade represents a serious human health risk via antimicrobial resistance [59] in the built environment, often associated with high-touch surfaces where it can remain viable for days [69][70][71]. Finally, because one of our metagenomes contained a high relative abundance of Staphylococcus-associated reads, we were confident that we would find Staphylococcus within the culture isolates generated from that sample.…”

Toothbrush microbiomes feature a meeting ground for human oral and environmental microbiota

“…DNA quality was measured with a Synergy HTX Multi-Mode Reader (BioTek, Winooski, VT, USA) and was considered acceptable for downstream analysis if the 260/280 ratio was between 1.7 and 2.1. DNA concentrations were quantified using the Quant-iT™ dsDNA Assay Kit (ThermoFisher Scientific, Waltham, MA, USA) [ 44 ]. Seven of the 34 samples were originally found to have relatively low yields of DNA that were below requirements for the library prep (0.2 ng uL −1 ); these samples were re-processed with the same steps above using 5 mL of toothbrush head supernatant.…”