Boston’s subway cars hold fewer harmful microbes than our guts

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Boston’s subway cars hold fewer harmful microbes than our guts

If you’re a fan of public transportation, you probably expect subway cars to be crawling with bacteria—after all, thousands of people ride them daily. But a new analysis of Boston's subway system says that may not be the case: The seats, hanging straps, and even the ticket machines in the transit system contained no higher levels of dangerous microbes than most people encounter in daily life. In the first survey of mass transit microbes to look at a variety of surfaces and materials, scientists took 100 samples from three separate rail lines, six different types of train surfaces, and the ticketing machines in stations. After sequencing the swabs, researchers found fewer microbes associated with antibiotic resistance than are found in a normal person's intestines, they report today in mSystems. Overall, only 46 antibiotic-resistant genes were found in the Boston subway system, far fewer than the roughly 1000 antibiotic-resistant genes found in the human gut. The most common microbe found was Propionibacterium acnes, the common and harmless skin bacterium known for causing acne. Human gut, oral, and even vaginal microbes were found in smaller quantities throughout the system. The most bacteria-laden surface was the subway's hanging grips, followed by seats and ticket machine touch screens. Researchers concluded that outside of flu or other outbreaks, the disease risks from riding the subway are fairly low. They aren’t saying how their findings will apply to other mass transit systems, but they do hope they can be used to better design public spaces to contain outbreaks. In the meantime, though, there’s no need to wear gloves while commuting.