Researchers have found that banknotes can transmit potentially pathogenic and antibiotic resistant strains of bacteria

May 18, 2017
Credit: CC0 Public Domain

If a commonly used item passed from person to person everyday around the world was found to carry potential harmful microbes, would you continue to use it? Dr Jun Li from the University of Hong Kong and his colleagues have been investigating the bacterial community present on banknotes, recently published in Frontiers in Microbiology.

Due to the global public health concern of antibiotic resistance, Dr Li and his team realized the importance of investigating how microbes are passed between humans and how antibiotic resistance can be spread around the world. To do this, were scraped from the surface of banknotes collected from hospitals and metro stations around Hong Kong in areas of varying population density and grown in the lab to determine the bacterial presence.

Despite doubt as to whether microbes can even survive on banknotes, the researchers found that the banknotes offer an environment that can, indeed, accommodate living bacteria. Over one third of the bacteria identified on the banknotes consisted of potentially pathogenic species. Widely recognized pathogens like Escherichia coli and Vibrio cholera were among these species, of which some strains can lead to death in infected people.

"In short, banknotes act as a medium 'absorbing' bacteria from other environments and the potential pathogens live quite well on the surface," said Dr Li.

Comparing the microbes found on banknotes with peoples' hands, metro station air, drinking water and , Dr Li and his team found that the banknotes harbour a much higher diversity of bacteria than that of the environmental samples.

When comparing the number of antibiotic-resistance between banknotes and the other environmental samples, Dr Li and his team found that the banknotes have a significantly higher abundance than the other samples. Of particular interest were clinically important antibiotic-resistance genes (those that are significant in the medical world) which were also higher in the banknotes.

"The high amount of antibiotic-resistance genes found from the banknotes is considerable and can potentially lead to the circulation of antibiotic resistance to humans and other environment," suggests Li.

When evaluating the dissemination potential of the identified antibiotic-resistance genes, researchers found that the banknotes have a significantly higher potential than the environmental samples. Combining the clinically important antibiotic-resistance genes with the high dissemination potential suggests currency could possibly pose a health risk.

"The most important results are that banknotes harbour various bacteria that originate from different environments including human hands, dirt and water due to its frequent contact with human hands and the environment. We also found that banknotes contain much higher amounts of genes and potential pathogens than other , like water and marine sediment."

Dr Li hopes that the findings of this study encourage a greater awareness of the potential risks in handling currency. "The most important recommendation we could raise is that before a cashless society develops, the banks and government should pay extra attention to the hygiene problem of the currency, which is still frequently used in our daily life. We recommend some routine disinfection of the currency from the bank, some public service ads reminding people to pay attention to wash the hands after touching currencies and the promotion of more electronic payment service, like mobile payment. We particularly would like to see the politicians and policy-makers inspired by this study."

Explore further: Bacteria in estuaries have genes for antibiotic resistance

More information: Yoshitaro Heshiki et al, Toward a Metagenomic Understanding on the Bacterial Composition and Resistome in Hong Kong Banknotes, Frontiers in Microbiology (2017). DOI: 10.3389/fmicb.2017.00632

Related Stories

Bacteria in estuaries have genes for antibiotic resistance

January 31, 2017
An international group of researchers, including Professor Michael Gillings from Macquarie University, have reported that pollution with antibiotics and resistance genes is causing potentially dangerous changes to local bacteria ...

Recommended for you

Motorcycle crashes cause five times as many deaths as car accidents, six times the health costs

November 20, 2017
Motorcycle accidents are costly in terms of lives and health care costs. Compared with car accidents, motorcycle accidents cause 3 times the injuries, 6 times the medical costs and 5 times the deaths, found new research in ...

New shoe makes running 4 percent easier, 2-hour marathon possible, study shows

November 17, 2017
Eleven days after Boulder-born Shalane Flanagan won the New York City Marathon in new state-of-the-art racing flats known as "4%s," University of Colorado Boulder researchers have published the study that inspired the shoes' ...

Vaping while pregnant could cause craniofacial birth defects, study shows

November 16, 2017
Using e-cigarettes during pregnancy could cause birth defects of the oral cavity and face, according to a recent Virginia Commonwealth University study.

Study: For older women, every movement matters

November 16, 2017
Folding your laundry or doing the dishes might not be the most enjoyable parts of your day. But simple activities like these may help prolong your life, according to the findings of a new study in older women led by the University ...

When vegetables are closer in price to chips, people eat healthier, study finds

November 16, 2017
When healthier food, like vegetables and dairy products, is pricier compared to unhealthy items, like salty snacks and sugary sweets, Americans are significantly less likely to have a high-quality diet, a new Drexel University ...

Children's exposure to secondhand smoke may be vastly underestimated by parents

November 15, 2017
Four out of 10 children in the US are exposed to secondhand smoke, according to the American Heart Association. A new Tel Aviv University study suggests that parents who smoke mistakenly rely on their own physical senses ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.