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Study: Commuter trains are home to living communities of bacteria


According to one Hong Kong study, commuter trains are actually home to living communities of bacteria. What’s worse is that they’re spread wide over the city by home time. Enjoy.



Good news for those of you who are taking the train home this evening, as you’ll be travelling in a crucible of bacterial life. A collection of scientists recently analysed the Hong Kong subway system and discovered that each line is home to its own microbial community, a community spread by the touch of commuters.


The University of Hong Kong asked volunteers to ride the subway, taking a particular effort to hold the handrails and have their palms swabbed upon their return.

Per the study: The majority of microbes they picked up were common skin bacteria, and the most abundant non-bacterial organisms were yeasts. In the morning rush hour, 140 species were detected, but by evening, many of those were no longer detectable and the populations of just 48 species had expanded to cover the entire system.

It seems that each microbial community seen in each route at the start of the day is determined from where the train starts, so even your bacteria can’t get out of your dead-end job and two-hour commute. Naw, twins!

Now, to the grimy details. The genes that were carried by the bacteria were mostly resistant to medical antibiotic drugs, but also tetracycline, which is an antibiotic used to treat a number of infections, including syphilis. Also, interestingly, added to pig feed. Those swines.

Interestingly the genes were easily detected on the morning trains, but had dispersed by the time that the volunteers took their evening ride.

Subtext: They’re everywhere, mannn.


“These studies are the first maps of their kind, and what is striking is the ubiquity of these antimicrobial-resistant genes we see around the world, but also that each city is unique,” says Chris Mason at Cornell University, who has studied the spread of bacteria through the New York subway system. “We don’t yet know which ones are the most significant for human health,” he says, but adds that studies like this can help tease that out.

Enjoy your commute home.

Just don’t touch anything. Or anyone.



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