Thursday, October 09, 2025

Little-known strep bacteria behind growing number of severe infections

An under-recognised strep bacterium is causing a growing number of serious infections in Australia, with First Nations Australians disproportionately affected, according to new research published today in The Lancet Microbe

University of Melbourne

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Blood agar plate in lab
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Credit: Doherty Institute

The study, led by the Peter Doherty Institute for Infection and Immunity (Doherty Institute), examined invasive infections caused by Streptococcus dysgalactiae subspecies equisimilis (SDSE), a close cousin to Streptococcus pyogenes (group A strep or Strep A). Like group A strep, SDSE can cause skin and soft tissue infections and, in severe cases, invade the blood and organs, leading to life-threatening illness.

For the first time, researchers measured the burden of invasive SDSE infections across Australia, comparing trends in southeast Australia and the Northern Territory’s Top End. The team analysed more than a decade of clinical and genomic data from hospitals across the regions. Building on earlier research into group A strep, they compared the incidence, demographics and outcomes of invasive SDSE (iSDSE) infections with those of invasive group A strep (iGAS), uncovering important differences in how the two pathogens spread and who they affect.

The University of Melbourne’s Dr Ouli Xie, Clinician Researcher in the Davies-Tong Laboratory at the Doherty Institute and first author of the paper, said the study revealed rising rates of infection and disparities between regions.

“We found that, in urban areas in southeast Australia, iSDSE infections occurred at a similar rate to iGAS and have steadily increased between 2011 and early 2023. In remote northern regions, iSDSE was less common than iGAS, but the number of cases was still 25 per cent higher than in southeast Australia,” said Dr Xie.

“For years SDSE has been seen as a minor player compared to group A strep, but our study shows it is causing a significant and rising burden of severe disease in Australia, predominantly in older Australians.”

The University of Melbourne’s Associate Professor Mark Davies, Laboratory Head at the Doherty Institute and co-lead author, said genomic analysis of patient samples uncovered important insights.

“Genome sequencing revealed that, although SDSE and group A strep are closely related, they behave differently in terms of transmission and recurrence, and they affect populations differently,” said Associate Professor Davies.

“This suggests that control strategies used for iGAS, like giving antibiotics to close contacts, may not work as well for iSDSE.”

The team also found that more than one in four cases were linked to stG62647, a bacterial clone of SDSE rapidly spreading in Europe and North America, and now in Australia.

The Royal Melbourne Hospital’s Professor Steven Tong, Group Head and Clinician Researcher at the Doherty Institute and co-lead author, said the findings shed light on health inequities faced by First Nations Australians in remote regions.

“Within the Top End itself, which already had higher rates of iSDSE than southeast Australia, First Nations Australians were further disproportionately affected, experiencing more than three times the risk of invasive disease compared with non-First Nations individuals,” said Professor Tong.

“We urgently need strategies that address the social determinants of health driving this burden, as well as new approaches to prevent and treat invasive strep infections.”

Together with the team’s earlier iGAS research (The Lancet Microbe, June 2025, 10.1016/j.lanmic.2024.101053), the findings provide the most comprehensive picture to date of invasive streptococcal disease in Australia. They highlight the urgent need for improved surveillance, prevention in vulnerable communities and exploration of vaccines or therapeutics, with industry partners such as Moderna already expressing interest in the genomic data with the goal of developing a vaccine that might work across both SDSE and group A strep.

Peer-review: Xie O, et al. Invasive Streptococcus dysgalactiae subspecies equismilis compares with Streptococcus pyogenes in Australia, 2011-23, and the emergence of a multi continent stG62647 lineage; a retrospective clinical and genomic epidemiology study. The Lancet Microbe (2025). DOI: http://www.doi.org/10.1016/j.lanmic.2025.101182
Collaboration: This work is a result of a collaboration led by the Doherty Institute with Monash Health, Menzies School of Health Research, University of Technology Sydney, Royal Darwin Hospital, Blacktown Hospital, Westmead Hospital, Northern Territory Department of Health and Monash University.
Funding: This research was supported by the Australian National Health and Medical Research Council (NHMRC) and the Avant Foundation.

Journal

The Lancet Microbe

DOI

10.1016/j.lanmic.2025.101182

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Invasive Streptococcus dysgalactiae subspecies equismilis compares with Streptococcus pyogenes in Australia, 2011-23, and the emergence of a multi continent stG62647 lineage; a retrospective clinical and genomic epidemiology study

Article Publication Date

7-Oct-2025

Nature inspires ANU tech to help recover trillions of dollars in critical resources

Australian National University

Australian scientists are harnessing the power of plants to help recover valuable resources from mining waste — **image:**
**Dr Samantha McGaughey (pictured) is harnessing the power of plants to help recover valuable resources from mining waste. Photo: Jack Fox/ANU**
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**Credit: Credit: Jack Fox/ANU**

An advanced filtration system inspired by nature that can recover untapped critical resources such as copper and lithium from mining waste is being developed by scientists from The Australian National University (ANU) in collaboration with Rio Tinto.

Using nanotechnology, the ANU researchers have bioengineered proteins that harness the advanced separation systems evolved by plants over billions of years. The research team has programmed the proteins, which have certain selective abilities, to separate and extract high-purity minerals and metals from mining wastewater, while simultaneously turning dirty water into clean water.

Industrial mining sites around the world contain an estimated $5.16 trillion worth of untapped critical resources that are trapped in wastewater. These metals and minerals are critical to the renewable energy transition, but in their waste form they are destructive to the environment.

According to Professor Caitlin Byrt, the “world-first” ANU-developed tech, known as Bioderived Element Resource Separation Technology (BERST), could help transform how mining waste is managed.

“Building a sustainable future depends on careful management of the critical resources required for the green energy transition. Mining operations deliver these critical resources but also generate substantial volumes of waste – there are currently tens of thousands of inactive and unrehabilitated mine sites in Australia,” Professor Byrt said.

Professor Byrt said BERST could dramatically cut the costs of mine closure and rehabilitation – costs that are estimated in Australia alone to be between $4-8 billion annually – while creating new revenue streams for mining companies.

“With approximately 240 Australian mines projected to close by 2040, and thousands more globally, there is an urgent need for innovative and effective waste management and rehabilitation strategies,” she said.

“Poorly managed mining waste can create environmental and safety risks and ongoing liabilities long after mining operations have ended. For example, acid mine drainage (AMD) impacts hundreds of thousands of kilometres of freshwater waterways, making reservoirs of freshwater unusable. AMD is ranked by the United Nations as second highest on its list of global environmental concerns, after climate change.

“This is where BERST comes in. The technology offers a simple yet effective solution to recycle and reuse these critical resources – that are essential to the clean energy transition – while helping mining sites reduce their environmental footprint.”

Dr Samantha McGaughey, also from ANU, said the BERST system could incorporate many different selective proteins – each one individually programmed to identify and recover a specific metal and mineral, demonstrating the technology’s accuracy, efficiency and adaptability to the wastewater composition.

“If you have a waste stream that's really complex, and there's 10 different metals or nutrients that you want to harvest from it, we could program each different protein to harvest every single one of those metals or nutrients simultaneously,” said Dr McGaughey, who was recently named the 2025 ACT Scientist of the Year.

As well as being able to extract the resources needed for food and energy security, BERST can also turn filthy mining wastewater into clean drinking water, offering a new and innovative solution to help bolster global water security.

“This is a huge benefit of this technology and probably what gives it an advantage over other types of technologies,” Dr McGaughey said.

“Plants have already done the hard work – they’ve evolved certain abilities to adapt to different environments with different soil compositions. This allows them to compartmentalise toxic things that they don't need or extract valuable metal and mineral nutrients that they do need in a very targeted way.

“With BERST, we’re adapting nature’s blueprints into a technology that can unlock valuable resources, reduce environmental impacts and make mine closure more economically and socially sustainable.”

According to the research team, BERST can take the form of many shapes and sizes, meaning the technology could be conveniently transported and deployed at any mine site worldwide with ease.

“BERST can be scaled anywhere from a two-litre portable unit to something equivalent to the size of a shipping container, through to an entire facility,” Professor Byrt said.

It’s hoped the tech, which is currently in the prototype testing stage, could be rolled out across the world, helping clean up the environmental damage caused by mine sites while at the same time recovering the materials needed to aid the renewable energy transition.

The technology concept is published in Mine Closure 2025 Australian Centre for Geomechanics | Conference Paper: Bioderived element resource separation technology for waste processing.

Images of Professor Caitlin Byrt and Dr Samantha McGaughey are available to download here.

DOI

10.36487/ACG_repo/2515_104

Article Title

Bioderived element resource separation technology for waste processing

World’s first pig-to-human liver xenotransplant in a living recipient reported in the Journal of Hepatology

Research in the Journal of Hepatology demonstrates that genetically engineered porcine livers can support key hepatic functions in humans

Elsevier

World’s First Pig-to-Human Liver Xenotransplant in a Living Recipient Reported in the Journal of Hepatology — image:
A landmark study in the *Journal of Hepatology* reports the world’s first auxiliary liver xenotransplant from a genetically engineered pig to a living human recipient.
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Credit: Journal of Hepatology / Zhang et al.

Amsterdam, October 9, 2025 – An important new study in the Journal of Hepatology, published by Elsevier, reports the world’s first auxiliary liver xenotransplant from a genetically engineered pig to a living human recipient. The patient survived for 171 days, offering proof-of-concept that genetically modified porcine livers can support key metabolic and synthetic functions in humans, while also underscoring the complications that currently limit long-term outcomes.

According to the World Health Organization, thousands of patients die every year while waiting for organ transplants due to the limited supply of human organs. In China alone, hundreds of thousands experience liver failure annually, yet only around 6,000 people received a liver transplant in 2022. This pioneering case offers a potential new avenue to bridge the gap between organ demand and availability.

The case involved a 71-year-old man with hepatitis B-related cirrhosis and hepatocellular carcinoma who was not eligible for resection or human liver transplantation. Surgeons implanted an auxiliary graft from a genetically modified Diannan miniature pig with 10 gene edits, including xenoantigen knockouts and human transgenes to enhance immune and coagulation compatibility.

For the first month after surgery, the graft functioned effectively, producing bile and synthesizing coagulation factors, with no evidence of hyperacute or acute rejection. However, on day 38, the graft was removed following the development of xenotransplantation-associated thrombotic microangiopathy (xTMA), a serious complication related to complement activation and endothelial injury. Treatment with the complement inhibitor eculizumab and plasma exchange successfully resolved the xTMA. Despite this, the patient later experienced repeated episodes of upper gastrointestinal hemorrhage and passed away on day 171.

“This case proves that a genetically engineered pig liver can function in a human for an extended period,” explained lead investigator Beicheng Sun, MD, PhD, Department of Hepatobiliary Surgery, and President of the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China. “It is a pivotal step forward, demonstrating both the promise and the remaining hurdles, particularly regarding coagulation dysregulation and immune complications, that must be overcome.”

“This report is a landmark in hepatology,” commented Heiner Wedemeyer, MD, Co-Editor, Journal of Hepatology, and Department. of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany, in an accompanying editorial. “It shows that a genetically modified porcine liver can engraft and deliver key hepatic functions in a human recipient. At the same time, it highlights the biological and ethical challenges that remain before such approaches can be translated into wider clinical use. Xenotransplantation may open completely new paths for patients with acute liver failure, acute-on-chronic liver failure, and hepatocellular carcinoma. A new era of transplant hepatology has started.”

“The publication of this case reaffirms the Journal of Hepatology as the world’s leading liver journal. We are committed to presenting cutting-edge translational discoveries that redefine what is possible in hepatology,” added Vlad Ratziu, MD, PhD, Editor in Chief, Journal of Hepatology, and Institute for Cardiometabolism and Nutrition, Sorbonne Université and Hospital Pitié Salpêtrière, Paris, France.