Revolutionary New Burn dressing 'lights up' to signal an infection

Scientists have developed a medical dressing that 'lights up' when a burn is infected.

It could be lifesaving in young children with serious burns in whom infections can rapidly become fatal, the Bristol researchers said. 

A prototype is available for demonstration purposes but trials in humans are still some years away.

Fast diagnosis of infection in children with burns, such as those caused by scalds from hot drinks, is a big problem for clinicians, the researchers said.

Current tests for an infected wound can take up to a couple of days but children - especially those of pre-school age - are particularly at risk from the effects of infection due to their relatively poor immunity.

They can quickly develop a condition called toxic shock syndrome, which if left untreated can be fatal in half of cases.

Fluorescent dye 
The dressing developed by scientists at the University of Bath uses nanocapsules containing a dye that burst open in the presence of disease-causing bacteria.

Using a UV light, doctors can quickly check whether there is infection by seeing if the dressing glows.

The nanocapsules are activated when they come into contact with toxins produced by harmful bacteria, so do not release the dye in response to normal bacteria that live on the skin.

So far the dressing has been tested on skin samples in the laboratory.

Dr Toby Jenkins

Dr Toby Jenkins, reader in Biophysical Chemistry at Bath, and project lead said about 5,000 children a year in England and Wales are treated in hospital for burns.

"The big problem for clinicians is the fast diagnosis of infection. Current methods take between 24 and 48 hours to get an answer as to whether the wound is infected.

"However, our burns dressing gives a simple colour change under UV light if a pathogenic, disease-causing bacteria is present in the burn, meaning clinicians can be alerted quickly to a potential infection."


Dr Amber Young, consultant paediatric anaesthetist at the South West Paediatric Burns Centre at Frenchay Hospital in Bristol and clinical adviser to the project said when a child with a small burn develops a high temperature there is no easy way of knowing if the child has a serious bacterial infection, or simply a cough or cold.

Dr Amber Young

"We currently have to remove the dressing to test for infection, which may result in slower healing and potentially life-long scarring and is very distressing for the child.

"This new dressing will mean we will be able to detect the early signs of infection so we can diagnose and treat the child quickly."

Prof Sheila MacNeil

Prof Sheila MacNeil, from Sheffield University, said the technology was based on two clever concepts - that it only reacts in the presence of life-threatening bacteria and that the florescent dye only shows up once the nanocapsules have burst.

"It has been developed for use in paediatrics but it could also be useful in lots of other contexts, such as the management of chronic ulcers in the home," she added.

Natural drug Abscisic Acid's infection fighting mechanism revealed

The scientists had reported some of the key molecular events in the immune system of mice that contribute to inflammation-related disease, including the involvement of a specific molecule found on the surface of immune cells involved in the body’s fight against infection (http://www.ncbi.nlm.nih.gov/pubmed/21068720). 

They have now gone one step further and revealed the mechanism by which the natural drug abscisic acid interacts with this protein, known as peroxisome proliferator-activated receptor-gamma, to block inflammation and the subsequent onset of disease.

“In previous work, our research group demonstrated that abscisic acid has beneficial effects on several conditions and diseases including obesity-related inflammation, diabetes, atherosclerosis, and inflammatory bowel disease,” said Josep Bassaganya-Riera, associate professor of immunology at the Virginia Bioinformatics Institute, leader of the Nutritional Immunology and Molecular Medicine Group in the institute’s CyberInfrastructure Division, and principal investigator of the study.

“One idea for how abscisic acid reduces inflammation in these instances is that it binds to a special region of peroxisome proliferator-activated receptor-gamma, a binding site known as the ligand-binding domain where the drug would be expected to latch on to and exert its effect. 

Our results show that this is not the case and, for the first time, we have demonstrated that abscisic acid works independently of this ligand-binding domain of the receptor.”

More information on this article here Science Blog

Newly engineered enzyme is a powerful staph antibiotic

Lysins that are effective against drug-resistant staph bacteria bore a hole through their cell walls.

The bacterium's contents ooze out, instantaneously killing it. (Credit: Image courtesy of Rockefeller University)

Newly engineered enzyme is a powerful staph antibiotic

With their best chemical antibiotics slowly failing, scientists are increasingly looking to nature for a way to control deadly staph bacteria -- the culprit behind most hospital infections.

Naturally toxic for bacteria, enzymes called lysins have the promising ability to obliterate staph, but the problem is producing large enough quantities of them to study how they work.

Rockefeller University scientists have now overcome this barrier by engineering a lysin that not only kills multidrug-resistant Staphylococcus aureus (MRSA) in mice, but also works synergistically with traditional antibiotics that have long been shelved due to resistance.

For the past five years, Vincent A. Fischetti, head of the Laboratory of Bacterial Pathogenesis and Immunology, and his colleagues have tried to clone a lysin that specifically targets staph, but they always ran into the same problem.

Although hundreds of thousands of lysins could be expressed in an engineered cell, they all would stick together forming an insoluble clump, rendering them inactive. "They were useless; a real thorn in our side," says Fischetti. "We've come across some problems cloning lysins for other bacteria, such as strep, but nothing to this extent."

Lysins, proteins derived from the viruses that have been infecting bacteria for billions of years, have two basic components. One acts as a recognition system to identify the specific bacteria species it has evolved to target; the other works like a molecular power drill that bores holes through the bacterium's cell wall, killing the organism. Together, these two components work so quickly and so efficiently that bacteria have no time to develop resistance.

Read the full article here

Viruses use 'Hive Intelligence' to spread Infection

A tactic familiar from insect behaviour seems to give viruses the edge in the eternal battle between them and their host – and the remarkable proof can be seen in a video.

The video catches viruses only a few hundred nanometres in size in the act of hopping over cells that are already infected. This allows them to concentrate their energies on previously uninfected cells, accelerating the spread of infection fivefold.

Geoffrey Smith and his team of virologists at Imperial College London were curious about the vaccinia virus, and set up a video microscope to watch how the virus spreads through cells.

Vaccinia and Smallpox
Vaccinia was used in the vaccine that rid the world of smallpox some 35 years ago. It doesn't cause disease in humans or any other animal, and its origin is unknown.

Spreading Infection
The traditional idea of how viruses spread goes like this. A virus first enters a cell and hijacks its machinery to make its own viral proteins and replicate. Thousands of replicated viruses then spread to neighbouring cells to wreak havoc.

When Smith watched the vaccinia virus infecting monkey liver cells, he thought that it was spreading far too quickly. "It takes 5 to 6 hours for the virus to replicate, but it was spreading from cell to cell within 1 or 2 hours," he says.

Spread of Vaccinia
Vaccinia is known to spread from cell to cell in a characteristic way. After attaching to the cell membrane of its target, it releases a protein that enters the cell, where it communicates with actin – a protein that helps maintain the cell's structure.

The actin responds by growing longer, and then attaches itself to the virus, still sitting on the surface of the cell, as a so-called "actin tail". This tail helps the virus take off from the cell and find the next victim.

Marking the Virus
Smith's team labelled the virus with green fluorescent protein, and labelled some – but not all – cells with a red marker that tagged the actin. They found, to their amazement, that a virus leaving a cell would travel to another cell and merely bounce off it if it already contained the virus.

Virus Changes
The researchers could tell that a single virus had travelled over more than one cell because some viruses which left a cell with an uncoloured actin tail picked up a red actin tail from another cell. "This means that the viruses can change their actin tails as they bounce along the surfaces of cells," says Smith. "This allows the virus to reach distant cells really quickly."

Smith reckons that two viral proteins which are presented on the surface of the infected cell effectively tell the virus not to bother reinfecting that cell. When he looked at virus strains lacking each of these proteins, the virus spread at the slower rate that would expected without the "bouncing infection" mechanism.

"It's as if the proteins are telling the virus: 'Hey guys, there's no point in coming in here'," says Smith. "If you think about it, it makes sense – it's very Darwinian."

The Full article is available here .........

Mosquito borne infection of Dengue Fever reaching Epidemic proportions in Philipines

A government worker fumigates a slum community in Manila in an attempt to control the spread of dengue fever.

Does Experimental Vaccine helps prevent HIV infection

For the first time, an experimental vaccine has prevented infection with the AIDS virus, a watershed event in the deadly epidemic and a surprising result.

Recent failures led many scientists to think such a vaccine might never be possible.
The vaccine cut the risk of becoming infected with HIV by more than 31% in the world's largest AIDS vaccine trial of more than 16,000 volunteers in Thailand, researchers announced Thursday.

Even though the benefit is modest, "it's the first evidence that we could have a safe and effective preventive vaccine," said Col. Jerome Kim. He helped lead the study for the U.S. Army, which sponsored it with the National Institute of Allergy and Infectious Diseases.

The institute's director, Dr. Anthony Fauci, warned that this is "not the end of the road," but said he was surprised and very pleased by the outcome.

"It gives me cautious optimism about the possibility of improving this result" and developing a more effective AIDS vaccine, Fauci said. "This is something that we can do."

Even a marginally helpful vaccine could have a big impact. Every day, 7,500 people worldwide are newly infected with HIV; 2 million died of AIDS in 2007, the U.N. agency UNAIDS estimates.

"Today marks an historic milestone," said Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition, an international group that has worked toward develping a vaccine.

"It will take time and resources to fully analyse and understand the data, but there is little doubt that this finding will energize and redirect the AIDS vaccine field," he said in a statement.