Christmas prawn shells helping to fight antibiotic-resistant super bugs, trial shows
Old prawn shells are ground down into a powder and used as an anti-microbial wound cover. (ABC News: Lexy Hamilton-Smith)
As we chow down on prawns, crab and lobster this Christmas, Queensland scientists are waiting in the wings to get their hands on the stinky leftovers.
- Prawn shells that normally end up in the trash are being used to heal wounds
- The white powder kills bugs that have become resistant to antibiotics
- Researchers say it’s a game changer for ulcer sufferers, particularly diabetics
Australians eat over 33,000 tonnes of crustaceans each year — according to the Fisheries Research and Development Corporation — and researchers at the Queensland University of Technology (QUT) have found a way to turn the old shells into a wound healer capable of fighting antibiotic-resistant bugs.
Trials have shown the anti-bacterial membrane, made from an active ingredient called chitosan, could fight off “golden staph”, a deadly super bug that has wreaked havoc in hospitals.
Lead researcher Dr Phong Tran said while the powder made from crustacean shells was not new, using it as an anti-microbial wound cover to combat deadly super bugs was.
Dr Phong Tran says trials found the membrane killed methicillin-resistant “golden staph”. (ABC News: Lexy Hamilton-Smith)
Dr Tran said trials found the membrane — when supercharged with an infusion of anti-microbial agents like selenium and silver — killed methicillin-resistant golden staph.
“It has been a long time that I have been working on this and from the tests we have done we are very confident that it works very well,” Dr Tran said.
“Crustacean shells contain the second most common biopolymer on Earth, after cellulose.
“The shells are cheap and abundant because they are normally just rubbish that you want to get rid of as fast as possible.”
He said after processing the shells to remove impurities such as heavy metals, chitosan was a safe, white raw powder material.
Dr Tran says the shells are cheap and abundant, and normally end up in the trash. (ABC News: Lexy Hamilton-Smith)
“We dissolve [it] in an acidic solution, pour a thin liquid layer into a container and freeze to allow the chitosan to form a network,” he said.
“We take the frozen container out and neutralise all the acid to peel off a flexible membrane, which has many properties appropriate for treating wounds.
“We found cells from the wound migrate into and grow well in these highly porous membranes.”
He said once it was loaded with anti-microbial agents like the selenium, it stopped super bugs growing and spreading.
In the laboratory at QUT’s Institute of Health and Biomedical Innovation, scores of petri dishes showed how the battle was being won.
“So I have here a petri dish full of super bugs everywhere … you see the golden colour,” Dr Tran said.
“Where I have the samples you see a clear zone where no bacteria can grow.
“Clear rings around the membrane discs show where the bacteria was killed.
“It is a solid circle that literally shuts off the antibiotic-resistant super bug and stops it growing and spreading.”
‘Game changer’ for ulcer sufferers
Dr Tran was collaborating with University of Melbourne to investigate the incorporation of more antibacterial agents in the membrane.
“Skin wounds caused by trauma or disease can sometimes be challenging to treat because of the widespread emergence of drug-resistant bacteria and fewer discoveries of new antibiotics,” Dr Tran said.
Queensland company Biomedical Innovation was also working on the project.
David Hewitt says it could heal ulcers for people with diabetes. (ABC News: Lexy Hamilton-Smith)
Lead scientist David Hewitt said the flexible membrane from old seafood shells, was a game changer for ulcer sufferers, particularly diabetics.
“Diabetic wounds like venous ulcers are extremely difficult to heal in a number of people,” Dr Hewitt said.
“We believe that this kind of material could really heal those recalcitrant wounds and give those people a new lease of life.”
The membrane, or hydro gel, was also found to be highly compatible with human skin, so it had the potential for use in skin grafts.
Researchers said a haemostatic bandage to rapidly stop bleeding was also in the pipeline.