TABLE 1.
Multivariate analysis between outdoor/indoor characteristics and microbial richness and compositional variation and fungal quantitya
| Characteristic | Bacteria |
Fungi |
||||
|---|---|---|---|---|---|---|
| Observed OTU, beta (95% CI) | Community variation (R2) | Observed OTU, beta (95% CI) | Community variation (R2) | Fungal DNA 1, beta (95% CI) | Fungal DNA 2, beta (95% CI) | |
| Climate/outdoor characteristics | ||||||
| Latitude | 0.10*** | 0.14*** | –0.40 (–0.62, –0.18)** | |||
| Proximity to the sea | 0.03* | 0.82 (0.37, 1.27)** | 0.89 (0.39, 1.38)** | |||
| Proximity to roads with heavy traffic | –63.65 (–127.05, –0.25)* | |||||
| Hotel/indoor characteristics | ||||||
| No. of yrs since redecorationb | –111.77 (–179.00, −44.55)** | –56.67 (–115.05, 1.72) | ||||
| Size of the hotel | 0.25 (–0.04, 0.54) | |||||
| Floor levelc | −0.21 (–0.39, –0.04)* | |||||
| Quality of the interiord | 0.04* | 0.02 | 0.39 (0.19, 0.59)*** | 0.26 (0.04, 0.48)** | ||
| Dampness or mold | 0.02 | 0.47 (0.09, 0.85)* | 0.77 (0.31, 1.23)** | |||
| Mechanical ventilation | –70.92 (–136.71, −5.12)* | |||||
| Floor typee | 0.06** | −25.71 (−47.60, −3.82)* | 0.02 | |||
| Sum R2 | 0.19 | 0.20 | 0.20 | 0.22 | 0.56 | 0.64 |
The microbial richness and fungal quantity were calculated by a forward stepwise linear multiple regression, and the microbial community was calculated by a forward stepwise Adonis multivariate analysis with 10,000 permutations. Only environmental characteristics with P < 0.1 were kept in the final multivariate model. Associations with P values of <0.05 are indicated by boldfacing and asterisks (***, P < 0.001; **, P < 0.01; *, P < 0.05), and associations with 0.05 < P < 0.1 are presented in regular typeface. Observed OTU values (α diversity) and fungal DNA 1 and 2 values (α diversity) are expressed as beta (95% CI); community variation values (β diversity) are expressed as R2. The sums of R2 values of the final multivariate model are also presented in the last row. Fungal DNA 1 was estimated by qPCR of the ITS1 region which captured at least 530 fungal species; fungal DNA 2 was estimated by qPCR of the 28S rRNA region which captured at least 140 fungal species. A detailed list of the fungal species captured was provided in previous publications (36, 80). A/C, air conditioning.
Number of years since redecoration: 0, >5 years; 1, <5 years.
Floor level: 1, ground; 2, top; 3, 2 to 4 floors; 4, 5 to 22 floors.
Quality of the interior: 1, high; 2, normal; 3, old.
Floor type: 1, stone; 2, wood; 3, plastic; 4, wall-to-wall carpet.