Bacteria on Classroom Surfaces Vary With Human Contact

Summary

The microorganisms inside the built environment often come from the occupants inside- mostly humans, pets, and plants. How we shape and operate the spaces in that built environment, and how we use the materials within that space, can affect the community of microorganisms living in a particular area, as well. By taking swab samples of multiple surfaces in a university classroom, we found that the bacterial communities on were different based on the surface (Figure 2A), and this difference was driven by a number of bacterial species (Figure 2B). In particular, we found that bacteria on surfaces in classrooms reflect how we use them– desks strongly resembled the bacterial communities found on skin, chairs reflected bacterial communities typical of both the gut and the vagina, and floor surfaces were a combination of human skin-associated and outdoor-associated bacteria, the latter presumably tracked in on shoes and clothing (Figure 2C).

Figure 2

Figure 2 Surfaces harbored significantly different bacterial communities and were linked to differential human contact. (a) Bacterial communities were constrained by four different surface types using distance-based redundancy analysis (DB-RDA; constrained inertia = 11.4%) and were significantly different among types based on Canberra taxonomic distances (P = 0.001 from permutational multivariate analysis of variation). (b) Bacterial operational taxonomic units (OTUs) from DB-RDA are shown weighting communities in the same four primary directions. The first and second axes from DB-RDA are used in both ordinations (CAP 1 and CAP 2) . The strongest ten weighting OTUs for each surface type are highlighted if they were also significant indicator OTUs (all P values <0.05). (c) All samples were compared to potential source environments using principal components analysis (PCA), and the first principal component (37.8% of variance explained) was used as a surrogate for community similarity to either phyllosphere or human skin bacterial communities. Boxplots delineate (from bottom) minimum value, Q1, median (Q2), Q3, maximum value; notches approximate 95% confidence around median value, and outliers fall outside of the quartile range. Letters above each box indicate significant groupings after Tukey’s hones significant difference (HSD) test (adjusted P value <0.05).

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Who’s Been Sitting In My Chair? The Microbes That Live Indoors

Ben Johnson, BioMed Central Biology Blog, 7 Mar 2014

Publications

“Bacterial Communities On Classroom Surfaces Vary With Human Contact” // Bio Med, Central, James F Meadow, Adam E Altrichter, Steven W Kembel, Maxwell Moriyama, Timothy K O’Connor, Ann M Womack, G Z Brown, Jessica L Green, Brendan J M Bohannan

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