A common ingredient in toothpaste and hand wash could be contributing to antibiotic resistance, according to University of Queensland research
A study led by Dr Jianhua Guo from UQ’s Advanced Water Management Centre focused on triclosan, a compound used in more than 2000 personal care products.
Dr Guo says that while it is well-known the overuse and misuse of antibiotics can create ‘superbugs’, researchers re unaware that other chemicals could also induce antibiotic resistance until now.
“Wastewater from residential areas has similar or even higher levels of antibiotic resistant bacteria and antibiotic resistance genes compared to hospitals, where you would expect greater antibiotic concentrations,” he says.
“We then wondered whether non-antibiotic, antimicrobial (NAAM) chemicals such as triclosan can directly induce antibiotic resistance,” Dr Guo says.
“These chemicals are used in much larger quantities at an everyday level, so you end up with high residual levels in the wider environment, which can induce multi-drug resistance.
“This discovery provides strong evidence that the triclosan found in personal care products that we use daily is accelerating the spread of antibiotic resistance.”
The researchers investigated whether the exposure to triclosan has an impact on inducing antibiotic resistance on Escherichia coli.
“Here, we report that at a concentration of 0.2 mg/L TCS induces multi-drug resistance in wild-type Escherichia coli after 30-day TCS exposure,” the researchers wrote.
“The oxidative stress induced by TCS caused genetic mutations in genes such as fabI, frdD, marR, acrR and soxR, and subsequent up-regulation of the transcription of genes encoding beta-lactamases and multi-drug efflux pumps, together with down-regulation of genes related to membrane permeability.
“The findings advance our understanding of the potential role of NAAM chemicals in the dissemination of antibiotic resistance in microbes, and highlight the need for controlling biocide applications.”
Advanced Water Management Centre Director, Professor Zhiguo Yuan, says the discovery should be a wake-up call to re-evaluate the potential 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 says.
Antimicrobial resistance has become a major threat to public health globally with approximately 700,000 people a year dying from antimicrobial-resistant infections.
The Review on Antimicrobial Resistance report predicted this will reach 10 million deaths a year by 2050 if no action is taken now.