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Hong Kong banknotes breeding ground for antibiotic-resistant superbugs, study finds

HK$20 bills have 48 times more antibiotic-resistant bacteria capable of being easily spread than samples collected elsewhere

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More than 100 species of potentially hazardous bacteria have been found on HK$20 banknotes. Other notes are likely to be similarly affected, except for polymer banknotes such as the HK$10 bill, which are less susceptible. Picture: SCMP

Sarah Lazarus

Published: 7:01am, 27 Jun 2017Updated: 11:02am, 27 Jun 2017

Hong Kong banknotes are teeming with antibiotic-resistant bacteria whose DNA can “jump around”, spreading resistance, a team of scientists at the University of Hong Kong has found.

Associate professor Gianni Panagiotou, who led the study, said there was a “relatively high risk” of an outbreak of infectious disease in the city.

Researchers collected wads of HK$20 notes from shops at 12 hospitals and three MTR stations across Hong Kong and then scraped bacteria from the money and analysed the DNA.

“We targeted hospitals because that’s where you find concentrations of people with a higher than average quantity of pathogens in their personal microbial ecologies,” says Panagiotou, also head of systems biology at the Hans Knoell Institute in Germany. “We thought any microbial trends would be amplified in the hospital environment, as well as at busy MTR stations.”

A researcher tests E. coli for antibiotic resistance. Picture: Alamy

The team identified 110 species of bacteria that are potentially hazardous to human health. Among the most dangerous were E. coli, which can cause diarrhoea, urinary tract infections, respiratory illness and pneumonia; Clostridium difficile, which can bring about severe inflammation of the colon and is notoriously hard to treat; and Vibrio cholerae, which can cause cholera.

The most abundant bacteria was Propionibacterium acnes, which lives in the skin pores and hair follicles of healthy people, but can trigger skin conditions including acne and blepharitis (infection of the eyelids).