Protein found in Sydney rock oysters’ haemolymph can kill bacteria and boost some antibiotics’ effectiveness, scientists discover
An antimicrobial protein found in the blood of an Australian oyster could help in the fight against superbugs, new research suggests.
Australian scientists have discovered that a protein found in the haemolymph – the equivalent of blood – of the Sydney rock oyster, Saccostrea glomerata, can kill bacteria itself and increase the effectiveness of some conventional antibiotics.
Antimicrobial resistance has been described as a “looming global health crisis” that – without urgent action – could render critical drugs ineffective and result in declines in lifespan and life quality by 2050.
In lab tests, the haemolymph protein alone was effective at killing the bacteria Streptococcus pneumoniae, which mainly causes pneumonia, and Streptococcus pyogenes, the culprit for strep throat and scarlet fever. It has not yet been tested in animals or humans.
When used in combination with antibiotics, including ampicillin and gentamicin, it improved their effectiveness from two- to 32-fold against bacteria such as Staphylococcus aureus (golden staph) and Pseudomonas aeruginosa, which often infects immunocompromised people.
The study’s co-author Prof Kirsten Benkendorff, of Southern Cross University, estimated that about two dozen oysters would contain enough haemolymph to provide an active dose of the protein for an average person, but she emphasised that more research was needed to purify the protein and understand how it works.
“We found that heating [the protein] does actually reduce the antimicrobial activity, so cooking would reduce the effect,” Benkendorff said.
It is uncertain, however, whether eating the protein would be effective, as unlike many conventional antibiotics, antimicrobial proteins can be broken down by the digestive system before they reach their target site.
“I definitely would not suggest that people ate oysters instead of taking antibiotics if they have got a serious infection,” Benkendorff said.
She said “oysters as filter feeding organisms are sucking bacteria in through their bodies all the time”, making them good candidates in which to look for new antimicrobial drugs – but also means that in places such as near stormwater drains, they can accumulate substances that can be harmful to humans if consumed.
Benkendorff said the protein could help treat respiratory infections that are resistant to regular antibiotics because of biofilms.
To protect themselves, infectious bacteria often aggregate into biofilms – sticky communities that enable them to better evade antibiotics and the human immune system.
The oyster haemolymph protein was effective against Streptococcus biofilms, the scientists found.
“We often think about bacteria just floating around in the blood. But in reality, a lot of them actually adhere to surfaces,” Benkendorff said. “The advantage of having something that disrupts the biofilm is … it’s stopping all of those bacteria from attaching to the surfaces. It’s releasing them back out into the blood, where then they can be attacked by antibiotics.”
Prof Jonathan Iredell, an infectious diseases physician and clinical microbiologist at the University of Sydney, who was not involved in the research, said the oyster protein belonged to a class of compounds called antimicrobial peptides. “There is a lot of excitement about their discovery because they often contain interesting kinds of mechanisms that we haven’t seen before.”
The study, he said, added “to an exciting field where we’re looking to naturally occurring antimicrobials of a different type to try and provide new prospects in the face of advancing adaptation by bacteria”.
Prof Branwen Morgan, who leads the CSIRO’s minimising antimicrobial resistance mission, described the protein’s properties as a “really interesting discovery, given biofilms are so problematic”.
Morgan, who was not involved in the research, said any potential treatment that reduced the reliance on traditional antibiotics was worth pursuing, in light of the increase in drug-resistant infections around thee world.
“Given the significant costs in developing new medicines, the idea of using excess and/or imperfect oysters to generate a sustainable supply of antimicrobial proteins … should be investigated further,” she said.
The study was published in the journal Plos One.

News
Unlocking hidden soil microbes for new antibiotics
Most bacteria cannot be cultured in the lab-and that's been bad news for medicine. Many of our frontline antibiotics originated from microbes, yet as antibiotic resistance spreads and drug pipelines run dry, the soil [...]
By working together, cells can extend their senses beyond their direct environment
The story of the princess and the pea evokes an image of a highly sensitive young royal woman so refined, she can sense a pea under a stack of mattresses. When it comes to [...]
Overworked Brain Cells May Hold the Key to Parkinson’s
Scientists at Gladstone Institutes uncovered a surprising reason why dopamine-producing neurons, crucial for smooth body movements, die in Parkinson’s disease. In mice, when these neurons were kept overactive for weeks, they began to falter, [...]
Old tires find new life: Rubber particles strengthen superhydrophobic coatings against corrosion
Development of highly robust superhydrophobic anti-corrosion coating using recycled tire rubber particles. Superhydrophobic materials offer a strategy for developing marine anti-corrosion materials due to their low solid-liquid contact area and low surface energy. However, [...]
This implant could soon allow you to read minds
Mind reading: Long a science fiction fantasy, today an increasingly concrete scientific goal. Researchers at Stanford University have succeeded in decoding internal language in real time thanks to a brain implant and artificial intelligence. [...]
A New Weapon Against Cancer: Cold Plasma Destroys Hidden Tumor Cells
Cold plasma penetrates deep into tumors and attacks cancer cells. Short-lived molecules were identified as key drivers. Scientists at the Leibniz Institute for Plasma Science and Technology (INP), working with colleagues from Greifswald University Hospital and [...]
This Common Sleep Aid May Also Protect Your Brain From Alzheimer’s
Lemborexant and similar sleep medications show potential for treating tau-related disorders, including Alzheimer’s disease. New research from Washington University School of Medicine in St. Louis shows that a commonly used sleep medication can restore normal sleep patterns and [...]
Sugar-Coated Nanoparticles Boost Cancer Drug Efficacy
A team of researchers at the University of Mississippi has discovered that coating cancer treatment carrying nanoparticles in a sugar-like material increases their treatment efficacy. They reported their findings in Advanced Healthcare Materials. Over a tenth of breast [...]
Nanoparticle-Based Vaccine Shows Promise in Fighting Cancer
In a study published in OncoImmunology, researchers from the German Cancer Research Center and Heidelberg University have created a therapeutic vaccine that mobilizes the immune system to target cancer cells. The researchers demonstrated that virus peptides combined [...]
Quantitative imaging method reveals how cells rapidly sort and transport lipids
Lipids are difficult to detect with light microscopy. Using a new chemical labeling strategy, a Dresden-based team led by André Nadler at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) and [...]
Ancient DNA reveals cause of world’s first recorded pandemic
Scientists have confirmed that the Justinian Plague, the world’s first recorded pandemic, was caused by Yersinia pestis, the same bacterium behind the Black Death. Dating back some 1,500 years and long described in historical texts but [...]
“AI Is Not Intelligent at All” – Expert Warns of Worldwide Threat to Human Dignity
Opaque AI systems risk undermining human rights and dignity. Global cooperation is needed to ensure protection. The rise of artificial intelligence (AI) has changed how people interact, but it also poses a global risk to human [...]
Nanomotors: Where Are They Now?
First introduced in 2004, nanomotors have steadily advanced from a scientific curiosity to a practical technology with wide-ranging applications. This article explores the key developments, recent innovations, and major uses of nanomotors today. A [...]
Study Finds 95% of Tested Beers Contain Toxic “Forever Chemicals”
Researchers found PFAS in 95% of tested beers, with the highest levels linked to contaminated local water sources. Per- and polyfluoroalkyl substances (PFAS), better known as forever chemicals, are gaining notoriety for their ability [...]
Long COVID Symptoms Are Closer To A Stroke Or Parkinson’s Disease Than Fatigue
When most people get sick with COVID-19 today, they think of it as a brief illness, similar to a cold. However, for a large number of people, the illness doesn't end there. The World [...]
The world’s first AI Hospital, developed in China is transforming healthcare
Artificial Intelligence and its developments have had a revolutionary impact on society, and healthcare is not an exception. China has made massive strides in AI integrated healthcare, and continues to do so as AI [...]