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
Scientists May Have Found a Secret Weapon To Stop Pancreatic Cancer Before It Starts
Researchers at Cold Spring Harbor Laboratory have found that blocking the FGFR2 and EGFR genes can stop early-stage pancreatic cancer from progressing, offering a promising path toward prevention. Pancreatic cancer is expected to become [...]
Breakthrough Drug Restores Vision: Researchers Successfully Reverse Retinal Damage
Blocking the PROX1 protein allowed KAIST researchers to regenerate damaged retinas and restore vision in mice. Vision is one of the most important human senses, yet more than 300 million people around the world are at [...]
Differentiating cancerous and healthy cells through motion analysis
Researchers from Tokyo Metropolitan University have found that the motion of unlabeled cells can be used to tell whether they are cancerous or healthy. They observed malignant fibrosarcoma cells and [...]
This Tiny Cellular Gate Could Be the Key to Curing Cancer – And Regrowing Hair
After more than five decades of mystery, scientists have finally unveiled the detailed structure and function of a long-theorized molecular machine in our mitochondria — the mitochondrial pyruvate carrier. This microscopic gatekeeper controls how [...]
Unlocking Vision’s Secrets: Researchers Reveal 3D Structure of Key Eye Protein
Researchers have uncovered the 3D structure of RBP3, a key protein in vision, revealing how it transports retinoids and fatty acids and how its dysfunction may lead to retinal diseases. Proteins play a critical [...]
5 Key Facts About Nanoplastics and How They Affect the Human Body
Nanoplastics are typically defined as plastic particles smaller than 1000 nanometers. These particles are increasingly being detected in human tissues: they can bypass biological barriers, accumulate in organs, and may influence health in ways [...]
Measles Is Back: Doctors Warn of Dangerous Surge Across the U.S.
Parents are encouraged to contact their pediatrician if their child has been exposed to measles or is showing symptoms. Pediatric infectious disease experts are emphasizing the critical importance of measles vaccination, as the highly [...]
AI at the Speed of Light: How Silicon Photonics Are Reinventing Hardware
A cutting-edge AI acceleration platform powered by light rather than electricity could revolutionize how AI is trained and deployed. Using photonic integrated circuits made from advanced III-V semiconductors, researchers have developed a system that vastly [...]
A Grain of Brain, 523 Million Synapses, Most Complicated Neuroscience Experiment Ever Attempted
A team of over 150 scientists has achieved what once seemed impossible: a complete wiring and activity map of a tiny section of a mammalian brain. This feat, part of the MICrONS Project, rivals [...]
The Secret “Radar” Bacteria Use To Outsmart Their Enemies
A chemical radar allows bacteria to sense and eliminate predators. Investigating how microorganisms communicate deepens our understanding of the complex ecological interactions that shape our environment is an area of key focus for the [...]
Psychologists explore ethical issues associated with human-AI relationships
It's becoming increasingly commonplace for people to develop intimate, long-term relationships with artificial intelligence (AI) technologies. At their extreme, people have "married" their AI companions in non-legally binding ceremonies, and at least two people [...]
When You Lose Weight, Where Does It Actually Go?
Most health professionals lack a clear understanding of how body fat is lost, often subscribing to misconceptions like fat converting to energy or muscle. The truth is, fat is actually broken down into carbon [...]
How Everyday Plastics Quietly Turn Into DNA-Damaging Nanoparticles
The same unique structure that makes plastic so versatile also makes it susceptible to breaking down into harmful micro- and nanoscale particles. The world is saturated with trillions of microscopic and nanoscopic plastic particles, some smaller [...]
AI Outperforms Physicians in Real-World Urgent Care Decisions, Study Finds
The study, conducted at the virtual urgent care clinic Cedars-Sinai Connect in LA, compared recommendations given in about 500 visits of adult patients with relatively common symptoms – respiratory, urinary, eye, vaginal and dental. [...]
Challenging the Big Bang: A Multi-Singularity Origin for the Universe
In a study published in the journal Classical and Quantum Gravity, Dr. Richard Lieu, a physics professor at The University of Alabama in Huntsville (UAH), which is a part of The University of Alabama System, suggests that [...]
New drug restores vision by regenerating retinal nerves
Vision is one of the most crucial human senses, yet over 300 million people worldwide are at risk of vision loss due to various retinal diseases. While recent advancements in retinal disease treatments have [...]