New test shows which antibiotics actually work

Some bacterial pathogens play dead to dodge antibiotics. A new test watches them closely—and helps choose drugs that finish the job
Image Credit: Scientific Frontline / AI generated

Drugs that act against bacteria are mainly assessed based on how well they inhibit bacterial growth under laboratory conditions. A critical factor, however, is whether the active substances actually kill the pathogens in the body. Researchers at the University of Basel have presented a new method for measuring how effectively antibiotics kill bacteria. 

Antibiotic-resistant bacteria are one of the biggest health problems of our time. Due to mutations, bacteria are increasingly resisting the effects of common drugs, making these infections increasingly difficult to treat. 

But even without resistance, bacteria are sometimes able to withstand antibiotics, especially if the bacteria are in a dormant state. Although they do not reproduce when in this state, they are not killed by the antibiotics either. This allows the bacteria to wake up and start growing again later, for example after antibiotic therapy has been stopped. Particularly in the case of tuberculosis and other complex infections, which take many months to treat, selecting drugs that kill the bacteria and completely sterilize the infection is crucial. 

The vast majority of US rivers lack any protections from human activities

The Skagit River, pictured above, runs through northwestern Washington. Nearly 160 miles of the Skagit and its tributaries are protected by the National Wild and Scenic Rivers designation to preserve its scenic value and enhance recreational opportunities.
Photo Credit: University of Washington

The Skagit River, pictured above, runs through northwestern Washington. Nearly 160 miles of the Skagit and its tributaries are protected by the National Wild and Scenic Rivers designation to preserve its scenic value and enhance recreational opportunities.University of Washington

The U.S. boasts more than 4 million miles of rivers, peppered with laws and regulations to protect access to drinking water and essential habitat for fish and wildlife. But in the first comprehensive review of river protection, research co-led by the University of Washington shows that the existing regulations account for less than 20% of total river length and vary widely by region.

Freshwater conservation strategies have historically emphasized protections against land use and development on public lands, including National Wildlife Refuges, Wilderness Areas and National Forests. However, protection measures that are specific to lakes, rivers and wetlands are much less common.

New study shows how the cell repairs its recycling stations

Leaks in the cell's lysosomes can be life-threatening. The discovery by researchers Yaowen Wu and Dale Corkery may help to understand and prevent diseases such as Alzheimer’s.
Photo Credit: Yue Li

When the cell’s recycling stations, the lysosomes, start leaking, it can become dangerous. Toxic waste risks spreading and damaging the cell. Now, researchers at Umeå University have revealed the molecular sensors that detect tiny holes in lysosomal membranes so they can be quickly repaired – a process crucial for preventing inflammation, cell death, and diseases such as Alzheimer’s. 

Lysosomes are the cell’s recycling stations, handling cellular waste and converting it into building blocks that can be reused. Lysosomal membranes are frequently exposed to stress from pathogens, proteins, and metabolic byproducts. Damage can lead to leakage of toxic contents into the cytoplasm, which in turn may cause inflammation and cell death. Until now, the mechanism by which cells detect these membrane injuries has remained unknown. 

TB harnesses part of immune defence system to cause infection

Photo Credit: Thirdman

Scientists have made a discovery that helps explain why humans and animals are so susceptible to contracting tuberculosis (TB) – and it involves the bacteria harnessing part of the immune system meant to protect against infection. 

Despite more than 100 years of research, tuberculosis remains one of the deadliest bacterial infections in humans, resulting in 1.5 million deaths each year. 

Tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis (MTB). Infection occurs when the bacteria are inhaled and taken up by specialist immune cells, such as macrophages, which recognize MTB and trigger a range of cellular and immune responses. These responses are mediated by receptors – molecules on the surface of immune cells that can recognize microbes. One such receptor is Dectin-1, which is best known for its role in anti-fungal immunity. 

Harnessing evolution: Evolved synthetic disordered proteins could address disease, antibiotic resistance

Yifan Dai and his team designed a method based on directed evolution to create synthetic intrinsically disordered proteins that can facilitate diverse phase behaviors in living cells. Intrinsically disordered proteins have different phase behaviors that take place at increasing or decreasing temperatures, as shown in the image above. The intrinsically disordered proteins on the left are cold responsive, and those on the right are hot responsive. The tree image in the center depicts the directed evolution process with the reversible intrinsically disordered proteins near the top. Feeding into the process from the bottom are soluble intrinsically disordered proteins.
Illustration Credit: Dai lab

The increased prevalence of antibiotic resistance could make common infections deadly again, which presents a threat to worldwide public health. Researchers in the McKelvey School of Engineering at Washington University in St. Louis have developed the first directed evolution-based method capable of evolving synthetic condensates and soluble disordered proteins that could eventually reverse antibiotic resistance.

Yifan Dai, assistant professor of biomedical engineering, and his team designed a method that is directed evolution-based to create synthetic intrinsically disordered proteins that can facilitate diverse phase behaviors in living cells. This allows them to build a toolbox of synthetic intrinsically disordered proteins with distinct phase behaviors and features that are responsive to temperatures in living cells, which helps them to create synthetic biomolecular condensates. In addition to reversing antibiotic resistance, the cells can regulate protein activity among cells. 

How Nutrient Availability Shapes Breast Cancer’s Spread

A microscope image of a breast cancer tumor (blue) and its surrounding microenvironment in a mouse model.
Image Credit: Joseph Szulczewski, David Inman, Kevin Eliceiri, and Patricia Keely/University of Wisconsin/National Institutes of Health

Scientists have gained new insights into how nutrient availability in different organs affects the spread, or metastasis, of breast cancer throughout the body.

In a study in mice jointly led by researchers at Harvard Medical School, Massachusetts General Hospital, and MIT, the team found that no single nutrient explains why breast cancer grows in one organ and not another. Instead, multiple nutrients and cancer cell characteristics work together to shape the spread of the disease.

The team also discovered that breast cancer cells require the nutrient purine to metastasize, regardless of their location or other nutrients available.

Local Magnetic Field Gradients Enable Critical Material Separations

A new high-throughput Mach–Zehnder interferometry imaging capability at Pacific Northwest National Laboratory, developed for critical minerals and materials extraction research, enables direct spatiotemporal imaging of ion concentrations in magnetic fields and reveals sustained concentration waves and rare earth ion enrichment regions driven by magnetic field gradients.
Photo Credit: Andrea Starr | Pacific Northwest National Laboratory

Rare earth elements (REEs) are crucial for energy-related applications and are expected to play an increasingly important role in emerging technologies. However, these elements have very similar chemical properties and naturally coexist as complex mixtures in both traditional and unconventional feedstocks, making their separation challenging. Researchers in the Non-Equilibrium Transport Driven Separations (NETS) initiative used standard low-cost permanent magnets to induce a magnetic field gradient in solutions containing REEs. They found that these permanent magnets create local magnetic fields strong enough to lead to regions enriched in REE ions, with concentration increases of up to three to four times the concentration of the starting solution. Directly observing magnetic field–driven ion enrichment in real time, without intrusive probes that disturb the system, has long been a challenge. The development of a new high-throughput Mach–Zehnder interferometry imaging capability has now enabled visualization of these dynamics as they unfold.

Study shows that species-diverse systems like prairies have built-in protection

The Rainfall and Diversity Experiment, where the study is based, was established at the KU Field Station in 2018. The site includes 12 constructed shelters, each with 20 plots planted with differing levels of plant species diversity and allowed different levels of precipitation. Research at the site continues.
Photo Credit: Courtesy of University of Kansas

Six years into a study on the effect of plant pathogens in grasslands, University of Kansas researchers have the data to show that species diversity — a hallmark of native prairies — works as a protective shield: It drives growth and sustains the health of species-diverse ecosystems over time, functioning somewhat like an immune system.

The research findings, just published in the Proceedings of the National Academy of Sciences (PNAS), have implications for management of native grassland, rangeland and agricultural lands. The results support regenerative agricultural approaches that strengthen the soil biome long-term, such as intercropping, rotation of different cover crops and encouraging a variety of native perennials (prairie strips) along field margins.

The study emphasized the interaction of changing precipitation and the loss of species diversity.

Scientists develop stronger, longer-lasting perovskite solar cells

Perovskite solar cell
Photo Credit: Xiaoming Chang

Scientists have found a way to make perovskite solar cells not only highly efficient but also remarkably stable, addressing one of the main challenges holding the technology back from widespread use. 

Perovskite has long been hailed as a game-changer for the next generation of solar power. However, advances in material design are still needed to boost the efficiency and durability of solar panels that convert sunlight into electricity. 

Led by Professor Thomas Anthopoulos from The University of Manchester, the research team achieved this by fine-tuning the molecules that coat the perovskite surfaces. They utilized specially designed small molecules, known as amidinium ligands, which act like a molecular “glue” to hold the perovskite structure together. 

This exotic form of ice just got weirder

Researchers paired ultrafast X-rays with specialized instruments to study the atomic stacking structures of superionic water – a hot, black and strangely conductive form of ice that is believed to exist in the center of giant ice planets like Neptune and Uranus.
Illustration Credit: Greg Stewart/SLAC National Accelerator Laboratory

Researchers hoped to clarify the boundaries between different types of superionic water – the hot, black ice believed to exist at the core of giant ice planets. Instead, they found multiple atomic stacking patterns coexisting in overlapping configurations never seen before in this phase of water. 

Superionic water – the hot, black and strangely conductive form of ice that exists in the center of distant planets – was predicted in the 1980s and first recreated in a laboratory in 2018. With each closer look, it continues to surprise researchers.

In a recent study published in Nature Communications, a team including researchers at the Department of Energy’s SLAC National Accelerator Laboratory made a surprising discovery: Multiple atomic packing structures can coexist under identical conditions in superionic water.