April 23, 2014 -- A study gives new meaning to the term "dirty money."
Researchers found that dollar bills from a Manhattan bank carried 3,000 types of bacteria. Most were the kind found on people's skin, while others were similar to those found in mouths and even in vaginas, ABC News reported.
While most of the bacteria detected on the dollar bills were associated with mild conditions such as acne, there were some antibiotic resistant types, including the superbug methicillin-resistant Staphylococcus aureus (MRSA), according to the researchers at the New York University's Center for Genomics and Systems Biology.
They said their study suggests that paper money could be a way for bacteria to pass between people. For example, they found that bills analyzed in winter were more likely than those tested in summer to carry bacteria that can cause pneumonia, which suggests that money could play a role in its spread, ABC News reported.
The study authors said people shouldn't be overly concerned about their findings.
"Microbes are so important, are very ubiquitous and they surround us all the time," lead investigator Jane Carlton, director of genome sequencing at the Center for Genomics and Systems Biology, told ABC News.
"We did find certain microbes that we might be a little concerned about, but that doesn't mean that people should be unduly concerned," she said.