Dirty money: thousands of disease-spreading microbes live on our cash

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A first-of-its kind genome study of the DNA on our money by researchers at New York University has discovered at least 3,000 kinds of bacteria that make their homes on our one-dollar bills.

This was many times more than in previous studies that examined samples under a microscope. Even so, they could identify only about 20 percent of the non-human DNA they found because so many microorganisms haven't yet been cataloged in genetic data banks, FOX reports. 

The project offers an in-depth look at the living organisms shacking up on our cash. One goal of the work is to provide information that could help health workers catch disease outbreaks in New York City before they spread very far, NPR reports.

"We're not trying to be fear mongers, or suggest that everyone goes out and microwave their money," Carlton told NPR. "But I must admit that some of the $1 bills in New York City are really nasty."

So far, Carlton and her colleagues have sequenced all the DNA found on about 40 dollar bills from a Manhattan bank. Their findings aren't published yet. But she gave Shots a sneak peak of what they've found so far.

Easily the most abundant species they found is one that causes acne, The Wall Street Journal reports. Others were linked to gastric ulcers, pneumonia, food poisoning and staph infections, the scientists said. Some carried genes responsible for antibiotic resistance.

"It was quite amazing to us," Jane Carlton, director of genome sequencing at NYU's Center for Genomics and Systems Biology told the WSJ. "We actually found that microbes grow on money."

Hygienists have long worried that currency could become a source of contagion.

"A body-temperature wallet is a petri dish," said Philippe Etienne, managing director of Innovia Security Pty Ltd., which makes special bank-note paper for 23 countries, the WSJ reports.

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