Dusting off microbes


Breaking down the microbiology world one bite at a time

Dusting off microbes

The EPA estimates that people spend approximately 90% of their day indoors. We can attribute this to various factors like work, technology, and health — especially since the COVID-19 pandemic. Health has made scientists especially curious, so they’ve conducted a study on 40 people (20 males, 20 females) at their offices in Xiamen city, Fujian, China. In other words, scientists want to determine indoor microbial makeup and how that impacts health/if that poses any increased health risks.

The study examines samples from each person’s ten digits, mouse, and keyboard. Scientists then extract these samples’ DNA before sequencing them. Such sequencing gives insight about the types of microbes that dominate the workspace; how those microbes distribute, then colonize; and whether those microbes cause human disease. 

The results of the study center around both the bacterial and fungal communities. Researchers involved have found that bacteria from phyla Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Cyanobacteria constitute the majority of bacteria found in all samples. Meanwhile, phyla Ascomycota and Basidiomycota have consistently prevailed for fungi. 

That said, where the microbes originate from have shown to differ significantly. 39% and 36% of bacterial dust microbes come from our participants’ keyboards and mice, respectively. Then, our participants’ fingerprints samples have 29% of their bacteria originate from said keyboards and mice. Collectively, 45% of microbes have external sources. Fungal microbes seem to display similar proportions, albeit fungal sources for keyboards and mice lend themselves equally. 

Microbial comparisons between each sample (finger, dust, keyboard, and mouse)

In other words, the microbes that compose the dust samples (or dust microbiomes) come from different places. More importantly, the above data tells us that most microbes in dust originate elsewhere other than traditional indoor sources (e.g., the workplace). 

Diverse sources means that we may find microbes with plant origins, human origins, insect origins, and many more. It also means that these different sources increase the risk of encountering pathogenic or disease-causing microbes. 

Unsurprisingly, scientists have discovered exactly those: 125 possible pathogenic microbes overall.

All of these results demonstrate a complex relationship between us and the surroundings. Factors such as our personal microbiomes, skin, sweat, and so on contribute to how much microbes grow as well as what types of microbes grow. Throw in unique workspace/environmental conditions (e.g., specific temperature, humidity, etc.) and we have a loaded microbial concoction. 

Make it especially potent with human movement: the more we touch things, the more easily we can transfer microbes from one place to another. Think about how often we interact with colleagues, make quick trips to the restroom, etc. This study emphasizessuch easy transmission in how quickly harmful microbes can spread/populate. 

Still, we can prevent or mitigate negative consequences with proper personal hygiene (i.e., hand-washing) and sanitation. It goes to show you how a little dusting can go a long way. 

Link to the original post: Hu Li, Shu-Yi-Dan Zhou, Roy Neilson, Xin-Li An, Jian-Qiang Su. Skin microbiota interact with microbes on office surfaces. Environment international, October 2022.

Additional sources

Featured image: https://pixabay.com/photos/computer-mouse-browser-research-2561477/