New copper surface eliminates bacteria in just two minutes

A new surface that kills bacteria more than 100 times faster and more effectively than standard copper could help combat the growing threat of antibiotic-resistant superbugs. The new copper product is the result of a collaborative research project with RMIT University and Australia’s national science agency, CSIRO, with findings just published in Biomaterials. Copper has long been used to fight different strains of bacteria, including the commonly found golden staph, because the ions released from the metal’s surface are toxic to bacterial cells. But this process is slow when standard copper is used, as RMIT University’s Distinguished Professor Ma Qian explained, and significant efforts are underway by researchers worldwide to speed it up.

The copper magnified 500,000 times under a scanning electron microscope shows the tiny nano-scale pores in the structure

A standard copper surface will kill about 97% of golden staph within four hours,” Qian said. “Incredibly, when we placed golden staph bacteria on our specially-designed copper surface, it destroyed more than 99.99% of the cells in just two minutes.” “So not only is it more effective, it’s 120 times faster.” Importantly, said Qian, these results were achieved without the assistance of any drug. “Our copper structure has shown itself to be remarkably potent for such a common material,” he said.

The team believes there could be a huge range of applications for the new material once further developed, including antimicrobial doorhandles and other touch surfaces in schools, hospitals, homes and public transport, as well as filters in antimicrobial respirators or air ventilation systems, and in face masks. The team is now looking to investigate the enhanced copper’s effectiveness against SARS-COV-2, the virus that causes COVID-19, including assessing 3D-printed samples. Other studies suggest copper may be highly effective against the virus, leading the US Environmental Protection Agency to officially approve copper surfaces for antiviral uses earlier this year.

Source: https://www.rmit.edu.au/news/

Mimicking Insect Wings To Fight Superbugs

The wings of cicadas and dragonflies are natural bacteria killers, a phenomenon that has spurred researchers searching for ways to defeat drug-resistant superbugs. New anti-bacterial surfaces are being developed, featuring different nanopatterns that mimic the deadly action of insect wings, but scientists are only beginning to unravel the mysteries of how they work.

In a post published in Nature Reviews Microbiology, researchers have detailed exactly how these patterns destroy bacteria stretching, slicing or tearing them apart. Lead author, RMIT University’s Distinguished Professor Elena Ivanova, said finding non-chemical ways of killing bacteria was critical, with more than 700,000 people dying each year due to drug-resistant bacterial infection.

The nanopillars on the surface of a dragonfly wing (magnified 20,000 times)

Bacterial resistance to antibiotics is one of the greatest threats to global health and routine treatment of infection is becoming increasingly difficult,” Ivanova said. “When we look to nature for ideas, we find insects have evolved highly effective anti-bacterial systems. “If we can understand exactly how insect-inspired nanopatterns kill bacteria, we can be more precise in engineering these shapes to improve their effectiveness against infections. “Our ultimate goal is to develop low-cost and scaleable anti-bacterial surfaces for use in implants and in hospitals, to deliver powerful new weapons in the fight against deadly superbugs.”

The wings of cicadas and dragonflies are covered in tiny nanopillars, which were the first nanopatterns developed by scientists aiming to imitate their bactericidal effects. Since then, they’ve also precisely engineered other nanoshapes like sheets and wires, all designed to physically damage bacteria cellsBacteria that land on these nanostructures find themselves pulled, stretched or sliced apart, rupturing the bacterial cell membrane and eventually killing them.

The new review for the first time categorises the different ways these surface nanopatterns deliver the necessary mechanical forces to burst the cell membrane. “Our synthetic biomimetic nanostructures vary substantially in their anti-bacterial performance and it’s not always clear why,” Ivanova explained. “We have also struggled to work out the optimal shape and dimensions of a particular nanopattern, to maximise its lethal power“While the synthetic surfaces we’ve been developing take nature to the next level, even looking at dragonflies, for example, we see that different species have wings that are better at killing some bacteria than others. “When we examine the wings at the nanoscale, we see differences in the density, height and diameter of the nanopillars that cover the surfaces of these wings, so we know that getting the nanostructures right is key.”

Source: https://www.rmit.edu.au/

Laser Method Turns Any Metal Surface Into A Bacteria Killer

Bacterial pathogens can live on surfaces for days. What if frequently touched surfaces such as doorknobs could instantly kill them offPurdue University engineers have created a laser treatment method that could potentially turn any metal surface into a rapid bacteria killer – just by giving the metal’s surface a different texture. In a study published in the journal Advanced Materials Interfaces, the researchers demonstrated that this technique allows the surface of copper to immediately kill off superbugs such as MRSA.

A laser prepares to texture the surface of copper, enhancing its antimicrobial properties

Copper has been used as an antimicrobial material for centuries. But it typically takes hours for native copper surfaces to kill off bacteria,” said Rahim Rahimi, a Purdue assistant professor of materials engineering. “We developed a one-step laser-texturing technique that effectively enhances the bacteria-killing properties of copper’s surface.”

The technique is not yet tailored to killing viruses such as the one responsible for the COVID-19 pandemic, which are much smaller than bacteria. Since publishing this work, however, Rahimi’s team has begun testing this technology on the surfaces of other metals and polymers that are used to reduce risks of bacterial growth and biofilm formation on devices such as orthopedic implants or wearable patches for chronic wounds.

Source: https://www.purdue.edu/

How To Kill Deadly Hospital Bacteria

Scientists at Aston University (UK) have discovered a technique similar to medieval stained glass-making that can completely eradicate the deadliest hospital infections within hours.

Using a so-called bioactive phosphate glass containing small amounts of the metallic element cobalt, the researchers were able to achieve a “complete kill” of the deadly bacterial infections E.coli and Candida albicans (a fungal infection associated with surgery), as well as a near-complete kill of Staphylococcus aureus (the drug-resistant form of which is MRSA).

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Lead researcher, Dr Richard Martin of Aston University in Birmingham, said the findings had significant implications, offering the possibility of cheap, antimicrobial implants and coatings to combat the most common sources of infections associated with medical care. Avoiding the need for antibiotics, it is also thought the bioactive glass could be effective against drug-resistantsuperbugs’, helping to tackle the growing problem of antimicrobial resistance (AMR).

According to the European Centre for Disease Prevention and Control (ECDC), over four million people in Europe get a healthcare-associated infection (HAI) every year, and around 37,000 die as a direct result of the infection. In its most recent survey of hospital patients, Public Health England found that 6.4% had a healthcare-associated infection.

In the study, published in the journal ACS Biomaterials, the researchers used a centuries-old technique to make glass laced with trace amounts of cobalt in a furnace heated to over 1,000°C, before rapid cooling to prevent crystallisation. These were then ground down into a fine powder and put into contact with bacteria in petri dishes. The glasses contained varying concentrations of cobalt, providing a controlled release of antimicrobial ions as they dissolved. At the highest concentration, the glass completely eradicated E.coli within just six hours, with a “complete kill” also observed for C.albicans within 24 hours. S.aureus levels were reduced by 99% after 24 hours.

Source: https://www2.aston.ac.uk/

Genetic Codes Mapping Of 3,000 Dangerous Bacteria

Scientists seeking new ways to fight drug-resistant superbugs have mapped the genomes of more than 3,000 bacteria, including samples of a bug taken from Alexander Fleming’s nose and a dysentery-causing strain from a World War One soldier. The DNA of deadly strains of plague, dysentery and cholera were also decoded in what the researchers said was an effort to better understand some of the world’s most dangerous diseases and develop new ways to fight them. The samples from Fleming – the British scientist credited with discovering the first antibiotic, penicillin, in 1928 – were among more than 5,500 bugs at Britain’s National Collection of Type Cultures (NCTC) one of the world’s largest collections of clinically relevant bacteria. The first bacteria to be deposited in the NCTC was a strain of dysentery-causing Shigella flexneri that was isolated in 1915 from a soldier in the trenches of World War One.

“Knowing very accurately what bacteria looked like before and during the introduction of antibiotics and vaccines, and comparing them to current strains, … shows us how they have responded to these treatments,” said Julian Parkhill of Britain’s Wellcome Sanger Institute who co-led the research. “This in turn helps us develop new antibiotics and vaccines.”

Specialists estimate that around 70 percent of bacteria are already resistant to at least one antibiotic that is commonly used to treat them. This has made the evolution of “superbugs” that can evade one or multiple drugs one of the biggest threats facing medicine today. Among the most serious risks are tuberculosis – which infects more than 10.4 million people a year and killed 1.7 million in 2016 alone – and gonorrhea, a sexually transmitted disease that infects 78 million people a year and which the World Health Organization says is becoming almost untreatable.

Source: https://www.reuters.com/