Superbug breakthrough by HKU researchers in fight against drug-resistant bacteria
New approach inhibits bacterial growth and the infection it causes
University of Hong Kong scientists have discovered a chemical compound that could treat a deadly superbug without using antibiotics, in a breakthrough offering hope for the global fight against drug-resistant bacteria.
The university’s top microbiologist, Professor Yuen Kwok-yung, said the study involving methicillin-resistant Staphylococcus aureus (MRSA) could help tackle a problem the World Health Organisation considers an “increasingly serious threat to global public health”.
The breakthrough came when the researchers enlisted a different approach from the conventional method of using antibiotics to kill bacteria, which has led to the growth of superbugs.
“If we don’t have to kill the bacteria but still inhibit its growth, we could solve the problem of antimicrobial resistance,” Yuen, who first proposed the idea in 2009, explained.
MRSA is one of the world’s most threatening superbugs. Yuen said around 45 per cent of all Staphylococcus aureus cases in Hong Kong were methicillin-resistant, or MRSA cases – four times higher than the percentage in Britain.
Patients infected with MRSA are more likely to be chronically ill in hospital and four times more likely to die than those infected with a non-resistant form of the bacteria.
In the latest study, the HKU scientists identified a chemical compound named NP16 that inhibited a substance produced by MRSA called staphyloxanthin, which can resist the body’s immune system.
“NP16 could stop MRSA in producing defensive shields ... now we have disarmed MRSA and allowed our body to kill the bacteria more easily,” lead researcher Dr Richard Kao Yi-tsun said.
“It would also be very difficult for the bacteria to cause infection.”
In experiments involving the cells and organs of infected mice, bacteria levels fell by a factor of 10 in a few days’ time with the help of NP16. The chemical compound was also revealed to be non-toxic to human cells.
“Once we killed the bacteria, there were always survivors that became drug-resistant,” Kao recalled. “Antibiotics use then became useless.”
The research team’s findings have been published in the scientific journal mBio, and the study received a top prize at a recent international conference. The team claimed the study was the world’s first to use chemical genetics to tackle MRSA infection.
Kao said the team had started to look into using the same approach to tackle other superbugs, including drug-resistant forms of E coli.
He added the team had been in touch with a local drug maker and the government to explore opportunities to develop NP16 into a drug. Kao expected it would take around three years to conduct pre-clinical research before the drug could be tested on patients in clinical trials.