Continental-scale microbiome study reveals different environmental characteristics determining microbial richness and composition/quantity in hotel rooms

Abstract

Culture-independent microbiome surveys have been conducted in homes, hospitals, schools, kindergartens and vehicles for public transport, revealing diverse microbial distributions in built environments. However, microbiome surveys have not been conducted in hotel environments; thus, the composition and associated environmental factors are not clear. We presented the first continental-scale microbiome study of hotel rooms (n = 68) spanning large geographic regions. Bacterial and fungal communities were described by amplicon sequencing of the 16S rRNA gene and internal transcribed spacer (ITS) region and quantitative PCR. Similar numbers of bacterial (4,344) and fungal (4,555) operational taxonomic units were identified, but fungal taxa showed a local distribution compared with bacterial taxa. Aerobic, ubiquitous bacteria dominated the hotel microbiome with high compositional similarity to previous samples from building and human nasopharynx environments. The abundance of Aspergillus was negatively correlated with latitude and accounted for [~]80% of the total fungal load in seven low-latitude hotels. We calculated the association between hotel microbial dynamics and 16 indoor and outdoor environmental characteristics. Fungal {beta}-diversity and quantity showed concordant variation and were associated with the same environmental characteristics, including latitude, quality of the interior, proximity to the sea and visible mold, while -diversity decreased with heavy traffic (95% CI: -127.05 to -0.25) and wall-to-wall carpet (95% CI: -47.60 to -3.82). Bacterial {beta}-diversity was associated with latitude, quality of the interior and floor type, while -diversity decreased with recent decoration (95% CI -179.00 to -44.55) and mechanical ventilation (95% CI: -136.71 to -5.12). ImportanceThis is the first microbiome study to characterize microbial composition and associated environmental characteristics. In this study, we found concordant variation between microbial {beta}-diversity and absolute quantity and discordant variation between {beta}-diversity/quantity and -diversity. Our study can be used to promote hotel hygiene standards and provide resource information for future microbiome and exposure studies associated with health effects in hotel rooms.