New insights could help phages defeat antibiotic resistant bacteria

University of Southampton

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Bacteria infected by phage. The dots show phage replicating.

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Credit: University of Southampton

Researchers at the University of Southampton have worked out how bacteria defend themselves against viruses called phages and the new insights could be key to tackling antibiotic resistance.

Phages are seen as a promising alternative treatment to antibiotics. Unpicking how bacteria protect themselves, and how phages might overcome these defences, could be a significant step in defeating antibiotic resistant bacteria.

Phages, known as bacteria eaters, look like a syringe with spider legs. They work by attaching themselves to bacteria. Once locked on, they inject their DNA into the bacterial cell, hijacking it to produce more copies of the virus before the cell bursts open and releases the new phages to attack other bacteria.

Crucially, phages only attack bacteria and are harmless to human cells.

The new research published today [28 July] in the journal Cell is the first to describe how a bacterial defence mechanism against phages, called Kiwa, works.

“In Māori mythology, Kiwa is a divine guardian of the ocean and its creatures,” says Dr Franklin Nobrega, Associate Professor at the University of Southampton and National Institute for Health and Care Research (NIHR) Southampton Biomedical Research Centre (BRC) Unit. “In bacteria, Kiwa also acts as a guardian, defending against phages, and are one of the most common defence mechanisms bacteria have.”

Researchers used advanced imaging techniques to study the interaction between phages and Kiwa at a molecular level.

They found Kiwa is made up of two components called KwaA and KwaB. This duo works together to form a kind of chainmail around the bacteria, preventing the phage DNA from entering.  KwaA acts like a sensor detecting the presence of a phage. Once this sensor is tripped, KwaB is alerted which binds to the phage DNA and turns it off before it can take over the cell.

But some phages have evolved a clever way to break through this two-step security system. They release a ‘decoy’ protein called Gam which tricks KwaB into attacking them while the real phage DNA slips through to complete the hijack.

Unfortunately for the phages, and us, Kiwa is one of many defence mechanisms bacteria have. Another is called RecBCD which also detects and attacks phage DNA. While the decoys work well against both systems independently, when they combine phages can’t break through.

Dr Nobrega explains: “In a similar way to how hackers are constantly looking for ways to bypass security systems, phages have evolved ways to breach the defences of bacteria. But just as tech companies adapt by releasing their latest update with improved security features, bacteria have evolved their own molecular firewalls in the shape of Kiwa and RecBCD.”

Finding new ways to fight bacteria is a pressing concern due to the growing threat of antibiotic resistance, which could kill ten million people a year by 2050 and costs the NHS £180m every year.

Dr Nobrega and his team at the University of Southampton are collecting phages which have the potential to overcome bacterial defences, and have identified over 600 different types to date.

They are inviting people to collect samples of dirty water (the perfect breeding ground for bacteria and phages) and post it into the lab for analysis.

“By improving our understanding of how these defence mechanisms operate, we can work out how to exploit weaknesses and select phages which have the best chance of breaking down the bacteria,” says Dr Nobrega.

“The more samples we are able to obtain, the better our chances of finding the best phages for the job.”

The paper Kiwa is a membrane-embedded defence supercomplex activated at phage attachment sites is published in Cell and is available online.

The research was funded by The Royal Society, Wessex Medical Research, Welch Foundation, National Institutes of Health and Simons Foundation. The Phage Collection Project is supported by the NIHR Southampton BRC Unit.

Ends

Contact

Steve Williams, Media Manager, University of Southampton, press@soton.ac.uk or 023 8059 3212.

Notes for editors

1. The paper Kiwa is a membrane-embedded defence supercomplex activated at phage attachment sites will be published in Cell. An advanced copy is available upon request.
2. For Interviews with Dr Franklin Nobrega please contact Steve Williams, Media Manager, University of Southampton press@soton.ac.uk or 023 8059 3212.
3. Images available here: https://safesend.soton.ac.uk/pickup?claimID=M2Xzjeo6XNzFUp5c&claimPasscode=oBit3JrkEGgPAhNX 

Additional information

The University of Southampton drives original thinking, turns knowledge into action and impact, and creates solutions to the world’s challenges. We are among the top 100 institutions globally (QS World University Rankings 2025). Our academics are leaders in their fields, forging links with high-profile international businesses and organisations, and inspiring a 22,000-strong community of exceptional students, from over 135 countries worldwide. Through our high-quality education, the University helps students on a journey of discovery to realise their potential and join our global network of over 200,000 alumni. www.southampton.ac.uk

www.southampton.ac.uk/news/contact-press-team.page

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About the NIHR
The mission of the National Institute for Health and Care Research (NIHR) is to improve the health and wealth of the nation through research. We do this by:

• Funding high quality, timely research that benefits the NHS, public health and social care;
• Investing in world-class expertise, facilities and a skilled delivery workforce to translate discoveries into improved treatments and services;
• Partnering with patients, service users, carers and communities, improving the relevance, quality and impact of our research;
• Attracting, training and supporting the best researchers to tackle complex health and social care challenges;
• Collaborating with other public funders, charities and industry to help shape a cohesive and globally competitive research system;
• Funding applied global health research and training to meet the needs of the poorest people in low and middle income countries.

NIHR is funded by the Department of Health and Social Care. Its work in low and middle income countries is principally funded through UK international development funding from the UK government.

On the left, bacterial cells are uninfected and Kiwa is inactive. On the right, bright spots appear inside the cells—these show Kiwa being activated after detecting a phage, helping to stop the infection before it takes hold.





This illustration shows a phage (virus) attaching to a bacterial cell. The Kiwa defence system (shown in yellow, green, and blue) detects the threat and binds the invading DNA, preventing the phage from hijacking the cell.



Credit

University of Southampton

Journal

Cell

DOI

10.1016/j.cell.2025.07.002 

Article Title

Kiwa is a membrane-embedded defence supercomplex activated at phage attachment sites

Article Publication Date

28-Jul-2025

Hybrid crystal-glass materials from meteorites transform heat control

Columbia University School of Engineering and Applied Science

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The article discusses how increasing disorder in the atomic structure of materials influences macroscopic heat conduction — a critical property for heat-management technologies. The materials studied include crystalline meteoritic tridymite (left), a tridymite phase featuring crystalline bond order and amorphous bond geometry (center), and completely amorphous silica glass (right). Red represents oxygen (O), blue represents silicon (Si), and common SiO4 tetrahedral arrangements are highlighted in shaded blue.

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Credit: Simoncelli Lab

Crystals and glasses have opposite heat-conduction properties, which play a pivotal role in a variety of technologies. These range from the miniaturization and efficiency of electronic devices to waste-heat recovery systems, as well as the lifespan of thermal shields for aerospace applications.

The problem of optimizing the performance and durability of materials used in these different applications essentially boils down to fundamentally understanding how their chemical composition and atomic structure (e.g., crystalline, glassy, nanostructured) determine their capability to conduct heat. Michele Simoncelli, assistant professor of applied physics and applied mathematics at Columbia Engineering, tackles this problem from first principles — i.e., in Aristotle’s words, in terms of “the first basis from which a thing is known” — starting from the fundamental equations of quantum mechanics and leveraging machine-learning techniques to solve them with quantitative accuracy.

In research published on July 11 in the Proceedings of the National Academy of Sciences, Simoncelli and his collaborators Nicola Marzari from the Swiss Federal Technology Institute of Lausanne and Francesco Mauri from Sapienza University of Rome predicted the existence of a material with hybrid crystal-glass thermal properties, and a team of experimentalists led by Etienne Balan, Daniele Fournier, and Massimiliano Marangolo from the Sorbonne University in Paris confirmed it with measurements. 

The first of its kind, this material was discovered in meteorites and has also been identified on Mars. The fundamental physics driving this behavior could advance our understanding and design of materials that manage heat under extreme temperature differences—and, more broadly, provide insight into the thermal history of planets.

A unified theory of thermal transport in atomically ordered crystals and disordered glasses

Thermal conduction depends on whether a material is crystalline, with an ordered lattice of atoms, or glassy, with a disordered, amorphous structure, which influences how heat flows at the quantum level–broadly speaking, thermal conduction in crystals typically decreases with increasing temperature, while in glasses it increases upon heating. 

In 2019, Simoncelli, Nicola Marzari, and Francesco Mauri derived a single equation that captures the opposite thermal-conductivity trends observed in crystals and glasses—and, most importantly, also describes the intermediate behavior of defective or partially disordered materials, such as those used in thermoelectrics for waste-heat recovery, perovskite solar cells, and thermal barrier coatings for heat shields. 

Using this equation, they investigated the relationship between atomic structure and thermal conductivity in materials made from silicon dioxide, one of the main components of sand. They predicted that a particular “tridymite” form of silicon dioxide, described in the 1960s as typical of meteorites, would exhibit the hallmarks of a hybrid crystal-glass material with a thermal conductivity that remains unchanged with temperature. This unusual thermal-transport behavior bears analogies with the invar effect in thermal expansion, for which the Nobel Prize in Physics was awarded in 1920.

That led the team to the experimental groups of Etienne Balan, Daniele Fournier, and Massimiliano Marangolo in France, who obtained special permission from the National Museum of Natural History in Paris to perform experiments on a sample of silica tridymite carved from a meteorite that landed in Steinbach, Germany, in 1724. Their experiments confirmed their predictions: meteoric tridymite has an atomic structure that falls between an orderly crystal and disordered glass, and its thermal conductivity remains essentially constant over the experimentally accessible temperature range of 80 K to 380 K. 

Upon further investigation, the team also predicted that this material could form from decade-long thermal aging in refractory bricks used in furnaces for steel production. Steel is one of the most essential materials in modern society, but producing it is carbon-intensive: just 1 kg of steel emits approximately 1.3 kg of carbon dioxide, with the nearly 1 billion tons produced each year accounting for about7% of carbon emissions in the U.S. Materials derived from tridymite could be used to more efficiently control the intense heat involved in steel production, helping to reduce the steel industry’s carbon footprint.

Future: from AI-driven solutions of first-principles theories to real-world technologies

In this new PNAS paper, Simoncelli employed machine-learning methods to overcome the computational bottlenecks of traditional first-principles methods and simulate atomic properties that influence heat transport with quantum-level accuracy. The quantum mechanisms that govern heat flow through hybrid crystal-glass materials may also help us understand the behavior of other excitations in solids, such as charge-carrying electrons and spin-carrying magnons. Research on these topics is shaping emerging technologies, including wearable devices powered by thermoelectrics, neuromorphic computing, and spintronic devices that exploit magnetic excitations for information processing.

Simoncelli’s group at Columbia is exploring these topics, structured around three core pillars: the formulation of first-principles theories to predict experimental observables, the development of AI simulation methods for quantitatively accurate predictions of materials properties, and the application of theory and methods to design and discover materials to overcome targeted industrial or engineering challenges.

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Lead Photo Caption: The article discusses how increasing disorder in the atomic structure of materials influences macroscopic heat conduction — a critical property for heat-management technologies. The materials studied include crystalline meteoritic tridymite (left), a tridymite phase featuring crystalline bond order and amorphous bond geometry (center), and completely amorphous silica glass (right). Red represents oxygen (O), blue represents silicon (Si), and common SiO4 tetrahedral arrangements are highlighted in shaded blue.

Lead Photo Credit: Simoncelli Lab

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DOI

10.1073/pnas.2422763122 

Article Title

Temperature-invariant crystal–glass heat conduction: From meteorites to refractories

Article Publication Date

31-Jul-2025

 

War's educational toll: NYU Tandon research reveals 78,000 Ukrainian students directly impacted by Russian war

Study shows 16% of graduating high school seniors displaced, with rural male students hit hardest by 'intersectional disadvantage’

NYU Tandon School of Engineering

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Russia's invasion of Ukraine has displaced approximately 36,500 graduating high school students — 16% of the country's 2022 senior class — while causing an additional 41,500 students to abandon the traditional pathway to higher education entirely, according to a new study published in Nature's Humanities and Social Sciences Communications.

The research, conducted by a multi-disciplinary team based in the United States and Ukraine and led by Julia Stoyanovich — Director of NYU's Center for Responsible AI, Institute Associate Professor of Computer Science and Engineering at NYU Tandon School of Engineering, and Associate Professor of Data Science at the NYU Center for Data Science — shows that at least 78,000 students (34% of all graduating high school seniors) were directly impacted by the war in 2022.

The team completed the study as part of the RAI for Ukraine Research Program, which Stoyanovich founded at NYU Tandon with partners from Ukrainian Catholic University in Lviv, in response to the war's disruption of Ukrainian higher education. The remote program is open to undergraduate and graduate students who live in Ukraine and are enrolled in degree programs in computer science, information systems, and related fields at accredited Ukrainian universities.

These students — RAI Research Fellows — are mentored by academic researchers from U.S. and European universities, and conduct cutting-edge collaborative research on a range of responsible AI topics. Students receive academic credit and competitive stipends.

The Nature study represents the first systematic analysis of student displacement and educational disruption following Russia's 2022 invasion, providing data for policymakers and humanitarian organizations.

"To the best of our knowledge, no information is available about the impact of the war on the internal and external displacement of high school students," said Stoyanovich. "Our analysis has important implications for governmental organizations and human rights organizations working to address the crisis."

Of the 36,500 displaced students identified, 64% migrated abroad, with most heading to Poland (30.7%), Germany (26.9%), and the Czech Republic (8.3%). The remaining 36% were internally displaced within Ukraine, typically moving from front-line regions toward the central and western parts of the country.

The regions most affected were those along the war's front lines: Kherson, Donetsk, Luhansk, Kharkiv, and Mykolaiv oblasts, where between 41% and 100% of students were registered in their home regions but took exams elsewhere.

The analysis also uncovered disparities in how different demographic groups experienced the war's educational impacts. Among displaced students, 84% came from urban areas despite rural students making up 31% of all test-takers.

The most severely affected group was rural male students, who experienced the greatest decrease in exam participation. "The impact of the war on drop-off for rural-males was greater than for either test-takers living in rural areas or males, indicating an intersectional disadvantage," said Stoyanovich.

Beyond displacement, the study documented a 21% decline in students taking Ukraine's standardized higher education entrance exam in 2022 compared to 2021—representing 41,500 fewer students.

Ukraine's response included rapidly digitizing its paper-based exam system into a computer-based National Multi-subject Test. This transition required developing new software and delivering it to hundreds of thousands of students, making the exam available in 32 countries worldwide for the first time.

The study's methodology relied on comparing students' official registration locations with where they physically completed their standardized exams, a novel approach that revealed displacement patterns invisible to traditional surveys. The researchers overcame significant technical challenges to create their analysis, curating "a uniquely comprehensive dataset of standardized exam outcomes used for admissions to higher education institutions in Ukraine—analogous to the Standardized Aptitude Test (SAT) in the United States," according to the researchers. The dataset encompasses approximately 1.5 million graduating students across eight years.

Ukraine's period of decommunization and decentralization between 2016 and 2023 created substantial data consistency challenges. To solve this problem, researchers assigned unique identifiers to each physical location and educational institution, allowing them to track entities consistently despite name changes and territorial redistricting.

The researchers warn that "reversing 'brain drain'—to the extent it is even possible—is no easy feat for any country" and note that "the issue may be time-sensitive: as the war continues, some families become more deeply rooted in their lives abroad."

In addition to Stoyanovich, the paper's authors are Tetiana Zakharchenko and Nazarii Drushchak from Ukrainian Catholic University, Oleksandra Konopatska from both Ukrainian Catholic University and Kyiv School of Economics, Andrew Bell, Ph.D. candidate at NYU Tandon and Falaah Arif Khan, Ph.D. student at the NYU Center for Data Science.

 The research was supported in part by a grant from the Simons Foundation.

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Journal

Humanities and Social Sciences Communications

DOI

10.1057/s41599-025-04675-5 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Estimating the impact of the Russian invasion onthe displacement of graduating high school students in Ukraine

 

Employees who spot problems help the bottom line, so why do leaders give more power to bootlickers?

North Carolina State University

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Two new studies find that leaders are less likely to empower followers who raise concerns about workplace decisions, even though these “challenging voice” employees play a critical role in highlighting problems and identifying solutions. The studies also outline what drives these decisions.

“We know that employee performance improves and employee turnover declines when employees are empowered – that’s good,” says Bradley Kirkman, co-author of a paper on the two studies. “We also know that having employees who use challenging voice are also beneficial to the bottom line – because this leads employees to be more creative, feel greater responsibility, innovate more, and share knowledge more often.”

So why are leaders not embracing this approach?

“That’s what we wanted to explore with these studies,” says Kirkman, who is the General (Ret.) H. Hugh Shelton Distinguished Professor of Leadership in North Carolina State University’s Poole College of Management.

At issue are behaviors known as “challenging voice” and “supportive voice.” Challenging voice refers to instances when an employee raises concerns about the status quo: potentially pushing back against leadership decisions, identifying potential problems with corporate strategy, etc. Supportive voice refers to instances when an employee is supporting the status quo: encouraging leaders, praising the workplace, and so on.

For the first study, the researchers enlisted 143 professional MBAs across multiple industries in China. The researchers also enlisted 266 employees who worked for those MBAs. In total, the study included 315 dyads consisting of a leader and a follower. The leaders and followers each completed three surveys over the course of six weeks. Each survey was designed to capture the behavior of both leaders and followers, and how the behavior of the followers influenced the behavior of leaders and how they viewed the followers.

For the second study, researchers recruited 528 adults in the United States. These study participants were given a common scenario in which they were a corporate leader and then asked questions aimed at assessing the participant’s willingness to empower an employee. However, study participants were given different descriptions of the employee’s behavior.

The researchers manipulated variables to give each participant one of six different employee descriptions. Participants were randomly assigned into a situation where the employee exhibited either challenging voice or supportive voice. Participants were then randomly assigned into scenarios in which the employee exhibited high or low challenging voice or high or low supportive voice (i.e., exhibited a range of challenging or supportive behaviors), along with high or low levels of behavior that helped the leader.

“The results were consistent across both studies,” Kirkman says. “Employees who exhibited challenging voice were less likely to be empowered; employees who use supportive voice were more likely to be empowered. In other words, managers favored bootlickers over boat-rockers.

“The reasons for this behavior were also the same in both studies,” Kirkman says. “Managers perceived employees who used challenging voice as threats to their leadership. On the other hand, leaders perceived the use of supportive voice as an indication that the employee shared the manager’s goals.”

However, the researchers did find one exception.

“In both studies, we found leaders were not threatened by challenging voice if an employee also exhibited high levels of helpful behavior,” Kirkman says. “If an employee was willing to buckle down and put in the work when the chips were down, such as helping leaders with heavy workloads, leaders were not threatened when that employee highlighted problems or raised concerns. High levels of helpful behavior didn’t influence the effects of supportive voice on how much leaders empowered their followers.”

There are two take-away messages here.

“For leaders, be conscious of the benefits that stem from empowering employees – and consider that not empowering people who challenge the status quo may adversely affect your bottom line,” says Kirkman.

“For employees, the message here is not that you shouldn’t speak out about potential concerns. Instead, the message is that you also need to exhibit helpful behavior, which will put you in a position to raise those concerns without fear of blowback.”

The paper, “Why Do Bootlickers Get Empowered More Than Boat-Rockers? The Effects of Voice and Helping on Empowering Leadership Through Threat and Goal Congruence Perceptions,” is published in the Journal of Applied Psychology. Corresponding authors of the paper are Troy Smith, an associate professor at the University of Oklahoma, and Pengcheng Zhang, an associate professor at the Huazhong University of Science and Technology. The paper was co-authored by Tobias Dennerlein, an assistant professor at Purdue University; and by Stephen Courtright, professor of management at Texas A&M University.

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Journal

Journal of Applied Psychology

DOI

10.1037/apl0001303 

Method of Research

Experimental study

Subject of Research

People

Article Title

Why Do Bootlickers Get Empowered More Than Boat-Rockers? The Effects of Voice and Helping on Empowering Leadership Through Threat and Goal Congruence Perceptions

Article Publication Date

25-Jul-2025

 

Could living near water mean you’ll live longer?

Oceans linked to benefits not seen near inland waterways

Ohio State University

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COLUMBUS, Ohio – Living within miles of the ocean breeze may be linked to a longer life, but you shouldn’t count on the same benefits if you live in a riverside city, suggests a recent study.

Researchers from The Ohio State University analyzed population data — including life expectancy — in more than 66,000 census tracts throughout the U.S. and compared it based on proximity to waterways. Their study was published online in the journal Environmental Research.

A correlation between longer life expectancy and water was clear for those who live within about 30 miles of an ocean or gulf. But for those who live in urban settings and near an inland body of water larger than 4 square miles, the opposite was true. Rural residents who live near water may also reap some lifespan advantages, according to the research.

“Overall, the coastal residents were expected to live a year or more longer than the 79-year average, and those who lived in more urban areas near inland rivers and lakes were likely to die by about 78 or so. The coastal residents probably live longer due to a variety of intertwined factors,” said lead researcher Jianyong “Jamie” Wu.

The analysis suggested that milder temperatures, better air quality, more opportunities for recreation, better transportation, less susceptibility to drought, and higher incomes could all be contributors to a better outlook for coastal residents compared to those who live inland.

“On the other side, pollution, poverty, lack of safe opportunities to be physically active and an increased risk of flooding are likely drivers of these differences,” said Yanni Cao, a postdoctoral researcher who worked on the study.

The most critical difference the researchers found is that coastal areas experience fewer hot days and lower maximum temperatures compared to inland water areas. 

Previous research has found a connection between living near water and better health measures, including higher physical activity levels, lower obesity rates and improved heart health. That prompted Wu to wonder if there could be a link between “blue space” living and longer lives, and how that relationship might differ depending on the type of neighborhood people call home, he said.

“We thought it was possible that any type of ‘blue space’ would offer some beneficial effects, and we were surprised to find such a significant and clear difference between those who live near coastal waters and those who live near inland waters,” said Wu, an assistant professor of environmental health sciences at The Ohio State University College of Public Health.

“We found a clear difference — in coastal areas, people are living longer,” said Wu, adding that the study is the first to comprehensively and systematically examine the relationship between various types of “blue space” and longevity in the U.S.

Cao said she was especially curious about how this data might provide insights into the trends in life expectancy in the U.S. compared to other wealthy nations. In the past several years, the U.S. experienced a sharper decline and a slower rebound in life expectancy than peer countries.

“It’s likely that various social determinants of health, including complex environmental factors, that contribute to health inequities are playing a key role in the differences we saw,” she said.

Ria Martins, a graduate student in public health, was also a co-author.

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Journal

Environmental Research