FIAT LUX

Shining light on titanium’s unique properties

A new method uncovers how titanium’s subatomic features influence its physical properties

Yokohama National University

 

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Shining intense infrared laser pulses on titanium generates higher-frequency light, revealing how its optical properties change in different directions due to variations in electron movement and bonding.

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Credit: Yokohama National University

A research team at Yokohama National University has developed a way to study how the orientation and behavior of electrons in titanium influence its physical characteristics. Their findings, published in Communications Physics on December 18, 2024, could pave the way for the development of more advanced and efficient titanium alloys.

Titanium is a very valuable metal because of its remarkable resistance to chemical corrosion, lightweight nature, and high strength-to-weight ratio. Its biocompatibility makes it ideal for medical applications, such as implants, prosthetics, and artificial bones, while its strength and durability are useful in aerospace and precision manufacturing.

To get an idea of how titanium's atoms and electrons generate these properties, the researchers used a process called high harmonic generation. “When we shine intense infrared laser pulses on a solid material, the electrons inside that material emit light signals at frequencies higher than that of the original laser beam,” explains the study’s first author, Professor Ikufumi Katayama of Yokohama National University’s Faculty of Engineering. “These signals help us study how the electrons behave and how the atoms are bonded.”

High harmonic generation is difficult with titanium and other metals, because the free electrons which make them excellent electrical conductors also interact strongly with the laser field and screen it in the material. This weakens the light signals, reducing their clarity and making it harder to collect data. “We carefully tuned the laser settings to reduce the screening effect, allowing us to clearly observe how titanium’s electronic structure behaves,” says Katayama.

The researchers used computer simulations to study the light signals emitted in response to the laser. They found that most of them came from electrons moving within certain zones called energy bands. These bands act like tracks where electrons can move freely. The direction of the laser and the way the titanium atoms are arranged affected how these electrons moved and bonded.

Titanium has a special uniaxial structure that can change with alloying, and its properties, like strength and flexibility, depend on the direction in which a force is applied. In other words, titanium behaves differently depending on the direction you push or pull on it. It turns out that this is because the way that the titanium atoms are arranged means the electrons don’t move the same way in all directions. When a laser hits titanium, the way the electrons absorb energy changes, affecting how they bond in different directions.

The researchers also found that fewer signals were emitted when electrons moved between different energy bands, showing that electron behavior is affected by the way atoms align. This difference determines whether the bonds are strong or weak, and thus how flexible or tough titanium is.

“By mapping how these bonds change with direction, we can understand why titanium has such unique mechanical properties,” says the study’s lead author, Dr. Tetsuya Matsunaga of the Japan Aerospace Exploration Agency. “That helps us understand how to design stronger titanium alloys that work better under different conditions, which could help create stronger, more effective materials for industries like aviation, medicine, and manufacturing.”

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Yokohama National University (YNU or Yokokoku) is a Japanese national university founded in 1949. YNU provides students with a practical education utilizing the wide expertise of its faculty and facilitates engagement with the global community. YNU’s strength in the academic research of practical application sciences leads to high-impact publications and contributes to international scientific research and the global society. For more information, please see: https://www.ynu.ac.jp/english/

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Journal

Communications Physics

DOI

10.1038/s42005-024-01906-0 

Article Title

Three-dimensional bonding anisotropy of bulk hexagonal metal titanium demonstrated by high harmonic generation

Metrology gets a new twist

Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, CAS

 

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Conceptual notion of twisted light probing a complex medium. An artistic illustration of twisted OAM light passing through a medium, where the OAM spectrum acts as a sensor to monitor its effects. The signature can be read out and analyzed using machine learning and AI algorithms to recognize or sense key features of the medium, as exemplified in the context of a turbulent atmosphere.

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Credit: Mingjian Cheng, Wenjie Jiang, Lixin Guo, Jiangting Li and Andrew Forbes

Metrology serves as the cornerstone of modern industry, providing the key standards by which we measure the world. Optical metrology, in particular, has historically leveraged on the notion of interference, essentially unchanged since the days of Thomas Young more than 200 years ago. However, can one glean more information by extrapolating the concept of fringes to other degrees of freedom?

 

In a recent paper published in Light: Science & Applications, a team of scientists led by Prof. Lixin Guo from Xidian University have shared their perspectives on the past, and future of optical metrology involving orbital angular momentum (OAM). The paper explores fundamental principles, applications, and seminal advancements in the field. The researchers demonstrate how twisted light carrying OAM can be used for new paradigms in measurement, for instance, 3D particle position tracking, utilizing a modern interpretation of the Doppler effect by observing frequency shifts that depend on both OAM and polarization.

 

“The original Doppler effect could only track movement toward or away from the observer, but the incorporation of orbital angular momentum in both scalar and vector light allows motion tracking in all directions, including rotational movement,” says Prof. Andrew Forbes, a corresponding author from South Africa. “This advancement has revolutionized the metrology of dynamic systems.”

 

It is not only the shift in paradigm for existing tools but also the invention of completely new instruments that is propelling the field forward. One such example is the concept of an OAM spectrum serving as the 'signature' of a system: when OAM light passes through a complex medium, its OAM is altered, resulting in changes to the shape of the OAM spectrum (see Figure 1).

 

"This OAM fingerprint of the medium contains a wealth of information that can be harnessed," says Dr. Mingjian Cheng, the lead author. As the review highlights, if the OAM spectrum is interpreted by machine learning and AI, it opens the door to real-time analysis and recognition of complex media, with OAM light serving as a probe, a topic that is gaining traction very fast.

 

The review not only covers metrology with classical light but also utilizing OAM in quantum entangled superpositions and single-photon states. Transitioning into the quantum domain holds the potential to reduce noise and enhance accuracy and precision with fewer measurements. However, this aspect of the field remains in its early stages of development. 

 

"Quantum metrology using OAM is still an emerging field with numerous untapped opportunities," says Prof. Andrew Forbes.

 

The comprehensive review spans a wide range of applications, from nano-sensing at the microscopic scale to measuring black holes at the cosmic scale. It provides an authoritative overview that will prove invaluable to both entry level and experienced researchers alike.

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Journal

Light Science & Applications

DOI

10.1038/s41377-024-01665-1 

Article Title

Metrology with a twist: probing and sensing with vortex light

 

Innovative wheelchair tyre design promises to revolutionise mobility and accessibility

Researchers have unveiled a groundbreaking design for manual wheelchair tyres that combines comfort, efficiency, and durability while reducing the maintenance challenges associated with traditional options.

Staffordshire University

 

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Design for a flexible-spoke non-pneumatic tyre for manual wheelchairs

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Credit: University of Staffordshire

Researchers have unveiled a groundbreaking design for manual wheelchair tyres that combines comfort, efficiency, and durability while reducing the maintenance challenges associated with traditional options.

The study, published in Scientific Reports, introduces Flexible-Spoke, Non-Pneumatic Tyres as an innovative solution for wheelchair users.

Unlike conventional pneumatic tyres, which require frequent air pressure maintenance and are prone to punctures, these concept tyres utilise a honeycomb-like flexible spoke structure that absorbs impacts and vibrations. These tyres also outperform some of the currently available solid non-pneumatic tyres, offering enhanced comfort and significantly reduced weight.

Dr Panagiotis Chatzistergos, the study’s senior author, Visiting Fellow at the University of Staffordshire and Lecturer at the University of Dundee, emphasised the innovation’s potential to elevate wheelchair technology: “This work showcases a significant step forward in wheelchair technology, combining comfort, efficiency, and durability in a single innovative design. Flexible-spoke non-pneumatic tyres have the potential to transform the mobility experience for wheelchair users, offering a tailored solution that eliminates maintenance burdens while enhancing performance and independence.”

This research highlights the adaptability of the proposed design, which can be tuned to meet individual needs. For instance, the tyres can be designed to offer stiffness for smooth wheeling efficiency and softness during impacts like curbs or rough terrain. This unique feature improves comfort and minimises energy demands, making it easier for users to propel their wheelchairs.

Professor Nachiappan Chockalingam, member of the Technical Advisory Group on Assistive technology at the World Health Organisation and a Visiting Professor at the University of Staffordshire co-authored the study. With extensive expertise in assistive devices and technology, he highlighted the broader impact of the innovation: “This research lays the foundation for a paradigm shift in wheelchair technology. By integrating innovative design with affordability, we aim to disrupt current practices and deliver life-changing solutions to those who need them most. This is about making advanced, high-performance assistive technology accessible to everyone, ensuring equity in mobility and independence.”

The reported research findings highlight the potential of this concept tyre to replace traditional wheelchair tyres, offering a reliable, cost-effective, and personalised solution for users worldwide. The technology also paves the way for future advancements in assistive devices, promising greater mobility and independence for millions of people.

Read the full paper A flexible-spoke non-pneumatic tyre for manual wheelchairs (Wyatt, O., Chatzistergos, P., Chockalingam, N. et alSci Rep 14, 29032 (2024).

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Journal

Scientific Reports

DOI

10.1038/s41598-024-79689-1 

Method of Research

Experimental study

Subject of Research

People

Article Title

A flexible-spoke non-pneumatic tyre for manual wheelchairs

 

Study finds videoconferencing impacts self-perception, desire for cosmetic procedures

Increased use of videoconferencing technology is connected to body image dissatisfaction

Boston University School of Medicine

 

(Boston)—The COVID-19 pandemic led to an unprecedented rise in the use of videoconferencing platforms such as Zoom, Google Meet, and Microsoft Teams. Experts have likened the videoconferencing experience to watching oneself in the mirror – the more time spent in front of a mirror or viewing oneself on video may lead to a more heavily scrutinized body image.

 

A new study from researchers at the Boston University Cosmetic and Laser Center at Boston Medical Center found widespread use of video calling platforms makes people more conscious of their appearance, driving them to seek cosmetic treatments.

 

“This phenomenon shares similarities with “Snapchat dysmorphia,” where people seek surgical changes to replicate their filtered images. This resonates with many people who, through videoconferencing, have started scrutinizing their appearance more closely than ever before, driving an increasing demand for cosmetic procedures," explained corresponding author Neelam Vashi, MD, associate professor of dermatology at Boston University Chobanian & Avedisian School of Medicine and director of the Center.

 

The researchers conducted a survey of 545 adults in the U.S. who answered questions about how often they used videoconferencing, how frequently they looked at themselves on video calls, and whether they used filters to improve their appearance. They were also asked about their interest in cosmetic procedures. The researchers then analyzed the responses using statistical methods to identify patterns and relationships between videoconferencing behaviors and the desire for cosmetic treatments.

 

They found videoconferencing influenced the desire for cosmetic procedures in 55.9% of participants, and 57.8% were influenced by filter use. Frequent self-viewing was reported by 67% of participants and was strongly associated with an interest in obtaining cosmetic procedures. Significant predictors of filter use included higher income and frequent self-viewing behavior. Notably, mask wearing was associated with increased self-esteem (68.8% of respondents) and a reduced desire for cosmetic procedures (67.4%) in frequent self-viewers.

 

According to the researchers, these findings may help dermatologists and cosmetic surgeons understand why increasing numbers of their patients are seeking cosmetic procedures. “Patients' desire for treatment may not always come from an inherent dissatisfaction but rather from the extended exposure to their digital reflections. This could help healthcare providers set realistic expectations and ensure that treatments are appropriate for their motivations,” said Vashi.

 

The researchers believe their study suggests that the increased focus on appearance due to videoconferencing could exacerbate body image issues or disorders, like body dysmorphic disorder (BDD). “In the future, this could lead to more interventions focusing on psychological well-being alongside cosmetic treatments and may impact how BDD is diagnosed or treated, especially in cases where patients are preoccupied with facial features highlighted during video calls,” she added.

 

These findings appear online in the Journal of Clinical and Aesthetic Dermatology.

 

Note to Editors:

Dr. Vashi is a consultant for Procter & Gamble, Pfizer, Janssen, UpToDate, and Unilever.

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Method of Research

Survey

Subject of Research

People

Article Title

Videoconferencing Dysmorphia: The Impact on Self-perception and Desire for Cosmetic Procedures

Article Publication Date

3-Jan-2025

COI Statement

Dr. Vashi is a consultant for Procter & Gamble, Pfizer, Janssen, UpToDate, and Unilever.

 SPACE/COSMOS

Citizen science reveals that Jupiter’s colorful clouds are not made of ammonia ice

University of Oxford

Collaborative work by amateur and professional astronomers has helped to resolve a long-standing misunderstanding about the composition of Jupiter’s clouds. Instead of being formed of ammonia ice – the conventional view – it now appears they are likely to be composed of ammonium hydrosulphide mixed with smog.

The findings have been published in the Journal of Geophysical Research – Planets.

The new discovery was triggered by amateur astronomer, Dr Steven Hill, based in Colorado. Recently, he demonstrated that the abundance of ammonia and cloud-top pressure in Jupiter’s atmosphere could be mapped using commercially-available telescopes and a few specially coloured filters. Remarkably, these initial results not only showed that the abundance of ammonia in Jupiter’s atmosphere could be mapped by amateur astronomers, they also showed that the clouds reside too deeply within Jupiter’s warm atmosphere to be consistent with the clouds being ammonia ice.

In this new study, Professor Patrick Irwin from the University of Oxford’s Department of Physics applied Dr Steven Hill’s analytical method to observations of Jupiter made with the Multi Unit Spectroscopic Explorer (MUSE) instrument at the European Southern Observatory’s Very Large Telescope (VLT) in Chile. MUSE uses the power of spectroscopy, where Jupiter’s gases create telltale fingerprints in visible light at different wavelengths, to map the ammonia and cloud heights in the gas giant’s atmosphere.

By simulating how the light interacts with the gases and clouds in a computer model, Professor Irwin and his team found that the primary clouds of Jupiter – the ones we can see when looking through backyard telescopes – had to be much deeper than previously thought, in a region of higher pressure and higher temperature.  Too warm, in fact, for the condensation of ammonia. Instead, those clouds have to be made of something different: ammonium hydrosulphide.

Previous analyses of MUSE observations had hinted at a similar result. However, since these analyses were made with sophisticated, extremely complex methods that can only be conducted by a few groups around the world, this result was difficult to corroborate. In this new work, Irwin’s team found that Dr Hill’s method of simply comparing the brightnesses in adjacent, narrow coloured filters gave the identical results. And since this new method is much faster and very simple, it is far easier to verify. Hence, the team conclude that the clouds of Jupiter really are at deeper pressures than the expected ammonia clouds at 700 mb and so cannot be composed of pure ammonia ice.

Professor Irwin said: “I am astonished that such a simple method is able to probe so deep in the atmosphere and demonstrate so clearly that the main clouds cannot be pure ammonia ice! These results show that an innovative amateur using a modern camera and special filters can open a new window on Jupiter’s atmosphere and contribute to understanding the nature of Jupiter’s long-mysterious clouds and how the atmosphere circulates.”

Dr Steven Hill, who has a PhD in Astrophysics from the University of Colorado and works in space weather forecasting, said, “I always like to push my observations to see what physical measurements I can make with modest, commercial equipment. The hope is that I can find new ways for amateurs to make useful contributions to professional work. But I certainly did not expect an outcome as productive as this project has been!”

The ammonia maps resulting from this simple analytical technique can be determined at a fraction of the computational cost of more sophisticated methods. This means they could be used by citizen scientists to track ammonia and cloud-top pressure variations across features in Jupiter’s atmosphere including Jupiter’s bands, small storms, and large vortices like the Great Red Spot.

John Rogers (British Astronomical Association), one of the study’s co-authors adds: “A special advantage of this technique is that it could be used frequently by amateurs to link visible weather changes on Jupiter to ammonia variations, which could be important ingredients in the weather.”

So why doesn’t ammonia condense to form a thick cloud? Photochemistry (chemical reactions induced by sunlight) is very active in Jupiter’s atmosphere and Professor Irwin and his colleagues suggest that in regions where moist, ammonia-rich air is raised upwards, the ammonia is destroyed and/or mixed with photochemical products faster than ammonia ice can form. Thus, the main cloud deck may actually be composed of ammonium hydrosulphide mixed with photochemical, smoggy products, which produce the red and brown colours seen in Jupiter images.

In small regions, where convection is especially strong, the updrafts may be fast enough to form fresh ammonia ice, and such regions have occasionally been seen by spacecraft such as NASA’s Galileo, and more recently by NASA’s Juno, where a few small high white clouds have been seen, casting their shadows down on the main cloud deck below.

Professor Irwin and his team also applied the method to VLT/MUSE observations of Saturn and have found similar agreement in the derived ammonia maps with other studies, including one determined from James Webb Space Telescope observations. Similarly, they have found the main level of reflection to be well below the expected ammonia condensation level, suggesting that similar photochemical processes are occurring in Saturn’s atmosphere.

Notes for editors:

For media enquiries and interview requests contact Professor Patrick Irwin, University of Oxford. Images available on request.

patrick.irwin@physics.ox.ac.uk

Tel: +44 (0)1865 272083

Mob: +44 (0) 7960752607

The new study “Clouds and ammonia in the atmospheres of Jupiter and Saturn determined from a band-depth analysis of VLT/MUSE observations”, Patrick G.J. Irwin et al., has been published in the Journal of Geophysical Research – Planets: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024JE008622

About the University of Oxford

Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the ninth year running, and ​number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.

Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.

Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 300 new companies since 1988. Over a third of these companies have been created in the past five years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.

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Journal

Journal of Geophysical Research Planets

DOI

10.1029/2024JE008622 

Article Title

Clouds and Ammonia in the Atmospheres of Jupiter and Saturn Determined From a Band-Depth Analysis of VLT/MUSE Observations

How astronomers used gravitational lensing

to discover 44 new stars in distant galaxy

JULIA JACOBO
Mon, January 6, 2025 at 11:43 AM MST

The most powerful telescope to be launched into space has made history by detecting a record number of new stars in a distant galaxy.

NASA's James Webb Space Telescope, history's largest and most complex space observatory that serves thousands of astronomers around the world, has captured a unique image that revealed 44 individual stars in a galaxy 6.5 billion light-years away from the Milky Way, according to a paper published Monday in Nature Astronomy.

MORE: This is how close NASA's Parker Solar Probe got to the sun

Astronomers used Webb's high-resolution optics and distortion in space to reveal the existence of dozens of previously unknown stars, the researchers said. The detection of a "treasure trove" of stars was only possible because the light from the 44 new stars was magnified by a large cluster of galaxies, called Abell 370, in front of it, according to the Center for Astrophysics.

The technique is known as gravitational lensing, which is when a massive amount of matter -- like a cluster of galaxies -- creates a gravitational field that distorts and magnifies the light from distant galaxies that are behind it but in the same line of sight, according to NASA. The effect is essentially like looking through a giant magnifying glass.

PHOTO: Abell 370 galaxy cluster. (NASA)

The strong gravitational magnification enabled astronomers to detect faint background sources and study their internal structures, which can lead to identifying individual stars in distant galaxies, according to the paper.

Gravitational lensing is also known as the "Einstein Ring" because renowned physicist Albert Einstein predicted the possibility in his theory of general relativity.

A visible arc created by gravitational lensing and the bending of light beyond Abell 370 was dubbed the "Dragon Arc." After carefully analyzing the colors of each of the stars inside the Dragon Arc, the researchers found many are red supergiants, which are stars in their final stages of life.

The discovery contrasts with earlier findings, which predominantly identified blue supergiants, which are among the brightest stars in the night sky, according to the Center for Astrophysics.

In the Milky Way and nearby galaxies, such as the Andromeda Galaxy, astronomers can observe stars one by one. But for galaxies billions of light-years away, the stars appear blended together due to the distance.

Newly discovered 'kiss and capture' mechanism explains the formation of Pluto and its largest moon

University of Arizona

 

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Snapshot of Pluto and Charon during kiss-and-capture.

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Credit: Robert Melikyan and Adeene Denton.

Billions of years ago, in the frigid outer reaches of our solar system, two icy worlds collided. Rather than destroying each other in a cosmic catastrophe, they spun together like a celestial snowman, finally separating while remaining forever linked in orbit. This is how Pluto and its largest moon, Charon, originated, according to a new University of Arizona study that challenges decades of scientific assumptions.

A study led by Adeene Denton, a NASA postdoctoral fellow who conducted the research at the U of A Lunar and Planetary Laboratory, has revealed this unexpected "kiss and capture" mechanism, which could help scientists better understand how planetary bodies form and evolve. By considering something planetary scientists had overlooked over decades – the structural strength of cold, icy worlds – researchers have discovered an entirely new type of cosmic collision.

The findings were published in the journal Nature Geoscience. 

For decades, scientists have theorized that Pluto's unusually large moon Charon formed through a process similar to Earth's moon – a massive collision followed by the stretching and deformation of fluid-like bodies, Denton said. This model worked well for the Earth-moon system, where the intense heat and larger masses involved meant the colliding bodies behaved more like fluids. However, when applied to the smaller, colder Pluto-Charon system, this approach overlooked a crucial factor: the structural integrity of rock and ice.

"Pluto and Charon are different – they're smaller, colder and made primarily of rock and ice. When we accounted for the actual strength of these materials, we discovered something completely unexpected," Denton said.

Using advanced impact simulations on the U of A's high-performance computing cluster, the research team found that instead of stretching like silly putty during the collision, Pluto and the proto-Charon actually became temporarily stuck together, rotating as a single snowman-shaped object before separating into the binary system we observe today. A binary system occurs when two celestial bodies orbit around a common center of mass, much like two figure skaters spinning while holding hands. 

"Most planetary collision scenarios are classified as 'hit and run' or 'graze and merge.' What we've discovered is something entirely different – a 'kiss and capture' scenario where the bodies collide, stick together briefly and then separate while remaining gravitationally bound," said Denton.

"The compelling thing about this study, is that the model parameters that work to capture Charon, end up putting it in the right orbit. You get two things right for the price of one," said senior study author Erik Asphaug, a professor in the Lunar and Planetary Laboratory. 

The study also suggests that both Pluto and Charon remained largely intact during their collision, with much of their original composition preserved. This challenges previous models that suggested extensive deformation and mixing during the impact, Denton said. Additionally, the collision process, including tidal friction as the bodies separated, deposited considerable internal heat into both bodies, which may provide a mechanism for Pluto to develop a subsurface ocean without requiring formation in the more radioactive very early solar system – a timing constraint that has troubled planetary scientists.

The research team is already planning follow-up studies to explore several key areas. The team wants to investigate how tidal forces influenced Pluto and Charon's early evolution when they were much closer together, analyze how this formation scenario aligns with Pluto's current geological features, and examine whether similar processes could explain the formation of other binary systems.

"We're particularly interested in understanding how this initial configuration affects Pluto's geological evolution," Denton said. "The heat from the impact and subsequent tidal forces could have played a crucial role in shaping the features we see on Pluto's surface today."

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Journal

Nature Geoscience

DOI

10.1038/s41561-024-01612-0 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Capture of an ancient Charon around Pluto

Article Publication Date

6-Jan-2025

 UH OH

Tuberculosis strains resistant to new drugs are transmitted between patients

Swiss Tropical and Public Health Institute

 

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By analysing the genomes of close to 90,000 TB strains from around the world, scientists from Swiss TPH and partners found that TB strains resistant to the new treatment regimen are already spreading between patients.

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Credit: Joachim Pelikan / Swiss TPH

Multidrug-resistant TB is a major concern

More than 10 million people fall sick with tuberculosis (TB) every year. The disease remains the world’s biggest infectious disease killers with an estimated 1.25 million annual deaths. The disease is still found in every country, but certain regions, such as India, Central Asia and Southern Africa, bear a particularly high burden. Multidrug-resistant TB (MDR-TB) continues to pose a major public health threat, adding to the growing concern of rising antimicrobial resistance.

The traditional treatment regimen for MDR-TB is lengthy, expensive, and comes with severe adverse event. In 2022, the World Health Organization (WHO) endorsed a new 6-month regimen – the BPaL(M) –, based on evidence of its improved safety and efficacy from numerous clinical studies, including TB-PRACTECAL.

Monitoring the implementation of a new treatment regimen

“While this new regimen is a game changer for patients suffering from MDR-TB, we knew that it will be difficult to outsmart Mycobacterium tuberculosis, the bacteria causing TB,” said Sébastien Gagneux, Head of the Department Medical Parasitology and Infection Biology at Swiss TPH and senior author of the study. “It was therefore crucial to study how the TB bacteria would react to the global roll-out of this new regimen.”

A study led by Swiss TPH in collaboration with the National Centre for Tuberculosis and Lung Diseases in Tbilisi, Georgia, published yesterday in the renowned New England Journal of Medicine now examined in detail whether resistance to the drugs in the new regimen has already emerged since its introduction, and whether this resistance is transmitting between patients.

Over a quarter of resistant strains result from transmission between patients

The researchers analysed the genomes of close to 90,000 M. tuberculosis strains from Georgia and many other countries around the world. They identified a total of 514 strains that were resistant to TB drugs, including both the old and the new treatment regimens. These highly drug-resistant strains were found in 27 countries across four continents.

Alarmingly, 28% of these strains were transmitted directly from one patient to another. “We already had anecdotal evidence of resistance emerging to the new regimen, but we did not know to what extent transmission was responsible for the spread of these highly drug-resistant strains,” said Galo A. Goig, postdoctoral collaborator at Swiss TPH and first author of the study.

“The good news is that the total number of these cases is still low. However, the fact that more than a quarter of these highly drug-resistant cases are due to patient-to-patient transmission, only two years after WHO endorsed the new regimen, is worrying,” added Goig.

Call for better surveillance and infection control

These findings have important implications for public health policy and interventions. “These new drugs have taken many years to develop, and to prevent drug resistance from emerging, it is essential to combine the deployment of these new regimens with robust diagnostics and surveillance systems,” said Chloé Loiseau, postdoctoral collaborator at Swiss TPH and co-author of the paper.

The authors emphasize the need for improved diagnostic tools, better infection control and robust surveillance systems to curb the spread of these highly drug-resistant strains, and to safeguard the efficacy of the new treatment regimen.

Tackling antimicrobial resistance

While there are already new TB drugs in the pipeline, experts worry that M. tuberculosis will continue to find ways to evade new drugs. “The example of these highly drug-resistant TB strains further illustrates that antimicrobial resistance is one of the most critical threats to global health today,” said Gagneux. “We must stay ahead in this constant race between drug development and bacterial resistance, and take proactive steps to prevent a ‘post-antibiotic era’ for TB and other diseases.”

About the study

The study was published yesterday in the New England Journal of Medicine. Swiss TPH led the study in collaboration with the National Center for Tuberculosis and Lung Diseases (NCTLD) in Tbilisi, Georgia. The work was supported by the Swiss National Science Foundation (SNSF) and the European Research Council (ERC).

https://www.nejm.org/doi/full/10.1056/NEJMc2404644

About tuberculosis

Tuberculosis (TB) is an infectious disease caused by Mycobaterium tuberculosis. TB is spread from person to person through the air. Symptoms of the disease include coughing, chest pain, weight loss, fever and night sweats. Multidrug-resistant tuberculosis (MDR-TB) is a form of TB caused by bacteria that do not respond to the two most effective first-line TB drugs. Only about 2 in 5 people with MDR-TB accessed treatment in 2022.

Swiss TPH’s contribution to the fight against TB

Swiss TPH is committed to alleviate TB-related suffering, working on five continents, from basic research to health systems strengthening. Activities include the investigation of the host-pathogen interaction, of the evolution of antibiotic resistance and of the host immune responses to infection and evaluations of TB initiatives and programmes. Swiss TPH also conducts clinical trials of new TB diagnostics, drugs and vaccines in collaboration with our long-term partners at the Ifakara Health Institute (IHI) in Tanzania and the National Center for Tuberculosis and Lung Diseases (NCTLD) in Georgia.

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DOI

10.1056/NEJMc2404644 

Subject of Research

People

Article Title

Transmission as a Key Driver of Resistance to the New Tuberculosis Drugs

Article Publication Date

6-Jan-2025