For years it's been the super-bug in hospitals around Australia. Golden staph, or Staphylococcus aureus, is resistant to a wide range of antibiotics, difficult to treat and seemingly impossible to eradicate.
Golden staph is one of the most aggressive infections imaginable; a bacterium that lives on the skin or in the nose which can cause a range of mild to severe infections and can be fatal if it enters the blood stream.
With more than 3000 Australians a year contracting the blood infection, and more than one-quarter of reported cases proving fatal, the threat is as real as it is perplexing for medical researchers who are trying to fight its onslaught.
Earlier research conducted by Menzies had revealed high levels of antibiotic-resistant golden staph in remote Indigenous communities across Northern Australia.
This was an unwelcome revelation to a problem that was already approaching epidemic proportions. Perhaps even more surprisingly was the identification of a unique clone of golden staph that on a genetic level was different from other golden staph found elsewhere in the world.
Research fellow with the Menzies School of Health Research, Dr Steven Tong has recently returned to Darwin after spending 18 months in the United States and the United Kingdom collaborating with some of the world’s foremost authorities on infectious diseases.
The inaugural Fulbright Northern Territory Scholarship recipient, Dr Tong travelled to North Carolina in 2011 where he partnered with leading researchers at Duke University Medical Centre, one of the world’s major centres for staphylococcal research, to explore the epidemiology and virulence of this unusual NT clone of golden staph.
“From a whole genome genetic study we knew that this NT clone lacked the ‘golden pigment’ found in most Staphylococcus aureus,” he said.
“With the assistance of leading researchers such as Duke University’s Associate Professor Vance Fowler, we compared the severity the infection caused by the NT strain with other S. aureus strains from around the world.
“We also put the ‘golden pigment’ into the NT strain to observe the resultant impact on virulence.”
Dr Tong said the findings revealed that the NT strain to be less virulent than most golden staph strains and surprisingly that the golden pigment made no difference to virulence in the NT strain.
“This is important because inhibiting the production of the golden pigment is seen as a potential therapy for S.aureus infections and our results suggest that such therapies may not work against all S.aureus strains – including the NT clone.”
The annual incidence of golden staph bloodstream infections is almost six times higher in the Indigenous community compared with the non-Indigenous population.
“Overcrowded houses, poor skin hygiene and high rates of skin infections are the most likely reason for the emergence of antibiotic-resistant strains,” he said.
“It is likely that these antibiotic-resistant golden staph strains have arisen in remote Indigenous communities where staphylococcal disease is highly prevalent.
“To actually combat this we need to get out into the communities and have community level interventions. And in particular in the Northern Territory that will involve improving housing and housing standards, making sure that houses have adequate facilities to actually wash children and improve their skin hygiene.”
Following his time at Duke, Dr Tong travelled to Cambridge where he partnered with researchers at the Wellcome Trust Sanger Institute to work on ‘next generation sequencing’ of a significant proportion of the Menzies S.aureus collection, including the entire collection of the NT strain. This work will elucidate how the NT strain differs from other S.aureus on a whole genome level.
Dr Tong reflects with fondness and easy nostalgia about his time abroad and the collaborations and friendships he has forged.
“I now have a much greater understanding and appreciation of the true power of collaborative research,” he said.
“I was lucky enough to partner with some of the preeminent experts in infectious diseases at Duke, the US National Institutes of Health, researchers in UCLA and the Wellcome Trust Sanger Institute.
“The relationships I built have established an ongoing collaborative link and should stand me in good stead to develop new treatments to combat the strains of staphylococcal skin disease threatening the health of those in the Top End.”