Biology subjects

Norbäck, D.

Publications and source records attributed to Norbäck, D..

2 recordsLinked to original sources

bioRxiv2019

Distinct microbiome composition of floor and air dust distort richness estimation in university dormitories

The number of culture-independent indoor microbiome study has increased remarkably in recent years, but microbial composition among different sampling strategies remains poorly characterized and their impact to downstream microbiome analysis is also not clear. In this study, we reported a case study of microbial composition of floor and air dust in 87 dormitory rooms of Shanxi University, China. Floor and air dust were collected by vacuum cleaner and petri-dish, respectively, and the bacterial composition was characterized by 16S rRNA sequencing. The composition of floor and air dust differed significantly (R2 = 0.65, p < 0.001, Adonis), and Pseudomonas dominated in floor dust (75.1%) but was less common in air dust (1.9%). The top genera in air dust, including Ralstonia (15.6%), Pelomonas (11.3%), Anoxybacillus (9.3%) and Ochrobactrum (6.2%), all accounted for < 1% abundance in floor dust. The dominant Pseudomonas in floor dust swamped low frequency organisms, leading to significant lower number of operational taxonomic units (OTUs) compared with air dust in the same sequencing depth. The different microbial composition of floor and air dust can lead to differences in downstream bioinformatics analyses. We searched the dormitory microbiome against ~200,000 samples deposited in Microbiome Search Engine (MSE), and found that the compositions of floor dust samples were similar to samples from building environment and human nasopharynx, whereas the compositions of the air dust samples were similar to mosquito tissues. ImportanceIncreasing number of indoor microbiome studies has been conducted in recent years, but the impact of sampling strategy is far from clear. In this study, we reported that the floor and air sampling can lead to drastic variation in microbial composition and downstream analyses in university dormitories, including microbial diversity estimation and compositional similarity search. Thus, the bioinformatics analysis results need to be interpreted with caution in microbiome studies, and it may be necessary to collected samples from different sampling strategies to comprehensively characterize the microbial composition and exposure to human occupants in an indoor environment.

microbiology↗

bioRxiv2019

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

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.

microbiology↗