resistance – Lightsources.org

New compounds to combat antibiotic resistance

2024/10/182024/11/06

To address the global threat of antibiotic resistance, scientists are on the hunt for new ways to sneak past a bacterial cell’s defence system. Taking what they learned from a previous study on cancer, researchers from the University of Toronto (U of T) have developed novel compounds that trigger bacterial cells to self-destruct.

The new form of antibiotics is designed to target a naturally occurring enzyme — caseinolytic protease proteolytic subunit, ClpP, for short — which chews up old or defective proteins and plays an essential role in cellular housekeeping. The new compound kicks the ClpP enzyme into overdrive, so it begins chewing up proteins that it is not supposed to, eventually killing its own cell from the inside out. Video: New compounds to combat antibiotic resistance

“Most antibiotics inhibit a process,” says Dr. Walid A. Houry, professor of biochemistry at the University of Toronto. “With this approach, we are dysregulating a process, and this allows us to develop this new class of compounds that we eventually hope to get into a clinic.” Houry worked closely with Dr. Robert Batey and colleagues to build upon their previous work in this area.

“It turns out that the [enzyme] present in cancer cells is also present in bacteria. For this project, the tricky thing was trying to find a way to hit the bacterial ClpP, but not the human ClpP.” Houry said.

Read more on CLS website

Understanding Stainless Steel’s Resistance to Hydrogen Embrittlement

2024/05/102024/05/20

Stainless steel is one of our most versatile materials. Its hygienic qualities ensure the safety of medical instruments and implants, and its corrosion-resistant properties make it indispensable in industries from construction to food processing. The corrosion resistance arises from the alloy’s chromium content, as the chromium forms a passive film on the surface that can self-heal in the presence of oxygen, shielding the bulk of the material from corrosion. However, the stability of the passive film can be affected by hydrogen absorption, leading to microstructure embrittlement that lowers the stress required for cracks to occur and propagate in the metal. A challenge for the hydrogen energy industry is that high-performance metallic materials are highly susceptible to hydrogen embrittlement. One potential candidate for building a safe hydrogen economy infrastructure is super duplex stainless steel (SDSS).

In work recently published in Applied Surface Science, an international team of researchers used in situ surface-sensitive synchrotron X-ray measurements to investigate the early stages of hydrogen-induced degradation of SDSS occurring at the near surface. Their results show that SDSS’s exceptional resistance to hydrogen embrittlement can be explained by the stability of the passive oxide film, and that the semiconducting property of the passive film plays an important role in hydrogen embrittlement. The authors also conclude that profound in situ experimental characterisation and computational calculation are needed to reveal the complex processes behind material degradation.

High-Strength, Corrosion-Resistant Steel

Green hydrogen can be used as both a feedstock and energy carrier and has the potential to play a crucial role in the future fossil-free energy landscape. However, high-strength metallic materials are highly susceptible to hydrogen embrittlement (hydrogen-induced material degradation), posing a significant challenge for safe hydrogen storage and transport.

Prof Jinshan Pan, from the KTH Royal Institute of Technology in Sweden, said:

Hydrogen embrittlement is a very important issue for many applications. Different metal materials may have this embrittlement problem. It’s really a hundred-years-old challenge. In many cases, the metal surface has a passive film, like an oxide, that allows materials to be used in practice, because otherwise the metals themselves are active.

Fighting food waste: Reducing grain spoilage in storage could help feed growing global population

2023/12/132023/12/19

Dr. Digvir Jayas is on a mission to stop grain spoilage. The researcher has been helping farmers and grain managers reduce spoilage losses for 40 years. He recently published a new study that used the Canadian Light Source at the University Saskatchewan to peer inside grains themselves, looking for the signs of spoilage and resistance.

Spoiled grain represents a huge pool of potential food that could help feed a growing global population. Spoilage rates vary greatly between grains and storage conditions, from as low as 1% of stored grain lost up to 50%.

“So, if you took an average of 20% loss, that would mean 640 million tonnes of grain is being lost globally on an annual basis,” says Jayas, who conducted the research while he was in the Department of Biosystems Engineering (Price Faculty of Engineering) at the University of Manitoba. “We could feed 1.5 billion people by preventing that loss through spoilage.”

To understand how the grain itself can be bred, and specific varieties selected to maximize storage potential, his team focused on hard durum wheat, which spoils less easily than soft wheats.

“The CLS has such a unique capability to look at the composition of materials at a nano or micro level. When grain spoils, there are unique changes occurring in the grain, and we were able to look at those changes.”

Read more on Canadian Light Source website

Undermining the foundations of bacterial resistance

2023/05/102023/05/12

Scientists from the University of Guelph have used the Canadian Light Source (CLS) at the University of Saskatchewan to better understand how several infectious bacteria, including E. coli., build a protective sugar-based barrier that helps cloak their cells.

Published in the Journal of Biological Chemistry, the Guelph research provides the very early steps toward new treatments for E. coli and a whole range of bacteria. Their particular focus is on strains of E. coli that cause urinary tract and bloodstream infections, particularly those that are antibiotic resistant.

The research is looking to understand the enzyme that many infectious bacteria use to build the foundations of their protective capsule. The capsule helps shield the bacterium from attack by the human immune system and exists in many clinically distinct variants.

Making vaccines or drugs that targets the capsule itself directly is impractical as such treatments would target only a few bacteria. Instead, the Guelph team is focused on a key enzyme that builds the capsule foundation. This foundation could serve as a common point of attack, allowing a single treatment for several key pathogens infecting humans and livestock.

“We are interested in the machinery that builds the bacterium’s protective layer,” said Dr. Chris Whitfield, Professor Emeritus in the Department of Molecular and Cellular Biology. “By understanding and targeting the machinery, we can render the pathogen unable to survive in the host”.

Read more on the Canadian Light Source website

Image : Matthew Kimber, Chris Whitfield, and enzyme