Concern over sanitiser ‘superbug’
Strain of bacteria Serratia marcescens has become resistant to disinfectants
IN A LABORATORY in the University of Free State a strain of bacteria is showing an adaptation that has scientists worried.
The strain of the bacteria Serratia marcescens has become resistant to disinfectants and this could be the sign of things to come where humankind could end up facing a pandemic worse than Covid-19.
“It is not regarded as a serious human pathogen but this strain that we have isolated is extremely resistant to disinfectants,” said Professor Robert Bragg, who is head of the Veterinary Biotechnology group, at the University of the Free State.
In a world where disinfectants have become one of the front-line weapons in the fight against the spread of Covid-19, scientists like Bragg are concerned that the pandemic will be helping in the evolution of strains of bacteria that are not only drug resistant but also disinfectant resistant.
“Ten years ago no one really thought about resistance to disinfectants,” explained Bragg. “Now the whole concept is picking up and becoming an issue. There is growing concern that because of Covid, every man and his dog is spraying you with some arbitrary unknown disinfectant every time you go in anywhere. And often there is very limited quality control.”
Other bacteria besides S marcescens have also been found to be highly resistant to several commercially available disinfectants. Fortunately they are still rare.
“The good quality registered disinfectants are generally fine,” explained Bragg. “But there is very little control of what is being used.
“If you dilute alcohol-based disinfectants even slightly, they won’t be effective. Also quite a few hand sanitisers have very low levels of other disinfectants in it. It is like you have a very nice chemical weapon and you are showing them very low concentrations of this and it is allowing them to build up resistance.”
This, coupled with growing antibiotic resistance in bacteria, could soon overshadow the current Covid-19 pandemic.
“Bacterial infections that are present in hospitals and agriculture are becoming unresponsive to many of the antibiotics currently in use, marking the start of a post-antibiotic era,” said Samantha McCarlie, Master’s student and laboratory manager, in a statement.
Tt has been predicted that antimicrobial resistance could lead to as many deaths as cancer causes today by 2050, and could account for between 10 and 50 million deaths a year.
Already these so-called superbugs have been found in hospitals across the country.
“It is a scary problem because we have run out of antibiotics,” said Bragg.
At the Veterinary Biotechnology group Bragg and his team are looking at ways of preventing bacteria from evolving disinfectant resistance.
Part of their research is understanding how S marcescens is developing disinfectant resistance, at a molecular level.
Their research includes taking environmental samples and testing levels of disinfectant resistance.
“Once the mechanisms are identified, possible solutions can be investigated,” said McCarlie.
Then they will be able to make recommendations to hospitals and the agricultural industry on how to fight these bugs.
Undergraduate students are also being used to evaluate different hand sanitisers as part of their practical training.
Vanessa Carter is an antimicrobial advocate and has experienced first hand the dangers of antibiotic resistant bacteria.
In 2011, she developed a methicillinresistant Staphylococcus aureus (MRSA) infection, that was related to a motor vehicle accident she had seven years earlier.
The infection nearly killed her. “What is very frightening is what I have witnessed and that is when we talk about these antibacterials in these hand sanitisers, people can sometimes get frightened because they say well it is going to become resistant anyway so I mustn’t sanitise my hands,” Carter said.
She believes the best way to combat antibiotic and disinfectant resistance is through education, and that the Covid-19 pandemic has helped with that.
“We need to realise that we can’t control nature, we need to rather respect nature,” she said.