Toothpaste, hand wash could be building 'superbugs', study shows

An ingredient found in thousands of personal care products, including some brands of toothpaste and hand wash, could be making certain bacteria resistant to antibiotics, a Queensland research paper has found.

Triclosan is an ingredient added to a range of products intended to reduce or prevent bacterial contamination, including hand wash, toothpaste and some cosmetics, according to the federal Department of Health.

In 2010 the European Union banned triclosan in all products that come into contact with food but still allowed for it to be present in toothpaste up to a maximum of 0.3 per cent.

The ingredient was banned from certain hand wash products in the United States in 2016 after studies raised the possibility its exposure could promote antibiotic-resistant bacteria.

Triclosan is found in a range of products including some hand wash. Photo: Wayne Venables

Triclosan is found in a range of products including some hand wash. Photo: Wayne Venables

University of Queensland Advanced Water Management Centre Dr Jianhua Guo decided to investigate the chemical compound further, which resulted in a paper published in Environment International on Tuesday.

Dr Guo said while it was known the overuse and misuse of antibiotics could create “superbugs”, less was known about whether other chemicals could induce antibiotic resistance.

Antimicrobial resistance has become a major public health threat globally, with about 700,000 people a year dying from antimicrobial-resistant infections, according to the paper.

The Brisbane paper noted previous wastewater studies conducted in South Africa found residential areas had similar or higher levels of antibiotic-resistant bacteria compared with hospital wastewater, where “you would expect greater antibiotic concentrations”, Dr Guo said.

“We then wondered whether non-antibiotic, antimicrobial chemicals such as triclosan can directly induce antibiotic resistance,” he said.

His research team exposed varied levels of triclosan to the bacteria E.coli, often found in the intestines of people and which can cause various diseases including pneumonia, urinary tract infections and food poisoning symptoms such as cramping and diarrhoea.

The research team found there was no significant increase in the mutation frequency of E.coli until day 30, when the exposure of triclosan at "an environmentally relevant" concentration, increased mutation frequencies in the bacteria E.coli against a number of antibiotics.

“This discovery provides strong evidence that the triclosan found in personal care products that we use daily is accelerating the spread of antibiotic resistance,” Dr Guo said.

UQ Advance Water Management Centre Director Professor Zhiguo said the discovery should be a wake-up call to re-evaluate the impact of such chemicals.

“While the US Food and Drug Administration (FDA) has banned the use of triclosan in antibacterial soap, the previous lack of unequivocal evidence prevented such a policy being adopted in other countries,” Professor Yuan said.

The federal Department of Health indicated in 2016 it was aware of FDA recommendations regarding antibacterial soups and would review the information to see whether action was required in Australia.

Fairfax Media approached the federal Department of Health for comment.

The research was funded by the Australian Research Council Future Fellowship and the UQ Foundation Research Excellence Awards.

brisbanetimes.com.au

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