The United States is a unique place, and each city has its own character and personality. They all look different and contain different people. Just like each city is different from those around it, the microbial content of the city is also unique. This microscopic environment has its own pattern and life which makes it distinct from other cities.
Researchers from Northern Arizona University took samples from Flagstaff, San Diego, and Toronto and analyzed the samples. Each city has a climate that it different from the other ones, which can influence the kinds of microbes that can grow. Samples were taken on surfaces like carpet, tile, or ceiling, and factors like humidity and temperature were accounted for. Bacteria, protists, and fungi were found which were unique to each city and office environment, but the microbial life was similar in each office in a particular city.
Previous research has confirmed the findings of this study. Researchers thought that they might find different microbes in office environments that were hotter or more humid than others, but found remarkably similar microbial climates in each city. Geography seemed to be the most influential factor in determining what kinds of microbial life would be found in a variety of local settings.
Research of this kind could help track the evolution of microbes as well as determine where people have travelled. Each person would have a unique microbiome around them based on where they have been, and if there was a database created for cities in the world, researchers could theoretically track where people have been down to the city level.
Each microbiome is influenced by geography and climate, and anyone or anything that travels through that climate (both indoors and outside) is changed by that microbiome. Microscopic organisms can stick to animal’s fur, the bottom of people’s shoes and even come in the air we breathe. All these factors can lead to a microscopic trail of where we’ve been.
Chase JH, Fouquier J, Zare M, Sonderegger DL, Knight R, Kelley S, Siegel JA, Caporaso JG. (2016) Geography and location are the primary drivers of office microbiome composition. PeerJ Preprints 4:e1797v1 https://doi.org/10.7287/peerj.preprints.1797v1
Cities Have Unique Microbial Signatures, New Study Says, Motherboard, April 19, 2016.