Microbiology: Every city has its own microbial footprint

Similar to humans, there is such a thing as a microbial nucleus that is the same in all. Differences in the microorganisms will outweigh how the team works Christopher Massen From Weill Cornell Medical College in New York on Thursday In the magazine “Cell” Writes.

Sample collection from Vienna to New York

The countless microbes in and on the human body are of great importance to our health, as they protect against disease-causing germs and other harmful environmental influences. However, the diversity of human microorganisms is constantly changing, for example due to diet and outside influences – so no microbiome is completely identical between two people.

The situation is similar to cities, as the first “metagenomic study of the urban microbiome” shows. To do this, the researchers collected genetic material directly from environmental samples. For three years, they took a total of 4,728 samples of seats, sales counters, grab bars, etc. on the subway in 60 cities: from Vienna to New York, from Bogata to Seoul, and from Kiev to Singapore.

31 species connect 60 cities

Genetic analyzes of these samples in the laboratory showed a “microbe core”: it consists of 31 species and occurs in more than 97 percent of samples. About half of these 31 species are associated with people who live in cities – that is, they come from their skin cells. The other half depends more on environmental factors, such as predominant rocks or water conditions, ”explains the bioinformatician and co-author of the study Alexandra Graf From FH Campus Wien vs Science .ORF.at.

However, this core is only a small part of the microbes generally found in cities. The researchers were able to assign more than 4000 discoveries to known species, about 1000 of which were distributed relatively often around the world. But they also found nearly 11,000 viruses, 1,300 bacteria, two ancient bacteria, and 800,000 genetic snippets that had not yet been listed in any database.

The microbiome as a fingerprint

The most common differences from similarities in microorganisms are the differences – cities have some kind of microbial fingerprint due to their microbiome. Study author Christopher Massen claims: “If you give me your shoes, I can tell you with up to 90 percent accuracy from which city and what part of the world I come from.”

However, that statement does not yet apply to Vienna at this time, according to Graff. The bioinformatics expert explains: “Of the 4,728 samples collected in the current study, only 16 are from Vienna. To be able to make a general statement about the microbiome in Vienna and how it differs from other cities, there is still very little information.” Not finished. After the research of the international scientific team, Graf is confident that it will be possible to define the Vienna microbiome more accurately in the coming years with more data sets.

Early detection of disease outbreaks

The results of the study could be used in several areas in the future. For example, by observing urban microbes, outbreaks of both known and unknown diseases and environmental changes can be detected at an early stage. In addition, the number of antibiotic-resistant viruses in, for example, urban settings can be recorded more accurately.