Showing posts with label Discovery. Show all posts
Showing posts with label Discovery. Show all posts

Bacterial 'Autopsy' Could Speed Antibiotic Discovery: Study

Scientists invent faster analysis of chemicals with bacteria-killing abilities; experts stress need for new generation of infection-fighting drugsStudy found drug used for one condition also
By Amy Norton
HealthDay Reporter
FRIDAY, Sept. 20 (HealthDay News) -- Scientists say they've found a quicker way to analyze chemicals with bacteria-killing abilities in an advance they hope will speed the development of new antibiotics.
With bacterial infections becoming increasingly resistant to existing antibiotics, new drug development is crucial, according to Dr. Stuart Levy, president of the Alliance for the Prudent Use of Antibiotics.
"There's a real need for new antibiotics," said Levy, a professor at Tufts University School of Medicine in Boston who was not involved in the new study. There are still questions about the novel testing method described in the study, according to Levy, "but it's a step in the right direction."
The approach, detailed in the Sept. 16-20 issue of Proceedings of the National Academy of Sciences, could make it simpler for researchers to figure out how a bacteria-killing chemical works.
That's important because many compounds are capable of knocking off the bugs, but drug developers need to know the "mechanism of action," explained Joseph Pogliano, the senior researcher on the new study and a microbiology professor at the University of California, San Diego.
As it stands, drug companies have a huge number of chemicals they can scour to find ones that kill bacteria. And out of millions of compounds, there maybe tens of thousands that slay the bugs.
"It's actually pretty easy to find compounds that can kill bacteria," Pogliano said.
What's difficult and time-consuming, he added, is analyzing those chemicals' "mechanism of action." Researchers need to know that, in part, so they can narrow the field to compounds that are likely to kill bacteria without hurting patients.
And still another reason, according to Pogliano, relates to the problem of antibiotic resistance. "Bacteria are becoming resistant to the drugs we have," he said, "so we need compounds that work by new mechanisms of action."
The current approach to uncovering mechanism of action involves multiple tests, and can take months, Pogliano said.
The method his team developed takes two hours and works like an "autopsy" of a bacterial cell. The researchers used what's called a high-resolution fluorescence microscope to examine cells killed off by a given antibiotic compound, and then determined the likely cause of death.
"It's one test where we can look at the cells and say they died of this mechanism," Pogliano said. "It's like a pathology report on a (deceased) person."
The findings come at a time when the problem of antibiotic resistance is getting heightened attention. The U.S. Centers for Disease Control and Prevention issued a report Monday saying that more than 2 million Americans fall ill with antibiotic-resistant bacterial infections each year. At least 23,000 of those people die, the agency said.

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Could Immune Cell Discovery Lead to Universal Flu Vaccine?

British study found people with more of certain virus-killing immune cells fared better during swine flu pandemicScientists engineer an enzyme to stop the
By Robert Preidt
HealthDay Reporter
MONDAY, Sept. 23 (HealthDay News) -- An experiment based on the 2009 H1N1 swine flu pandemic may have helped scientists move closer to developing a universal flu vaccine, according to a new study.
Researchers at Imperial College London, in England, asked 342 staff members and students to donate blood samples right as the pandemic was beginning in autumn 2009. They were also asked to report any symptoms they experienced over the next two flu seasons.
The goal was to determine why some people seem to resist severe illness when exposed to flu bugs. The researchers discovered that people who caught the flu but had only mild or no symptoms had more CD8 T-cells -- a type of virus-killing immune cell -- in their blood at the start of the pandemic.
The authors of the study, published online Sept. 22 in the journal Nature Medicine, believe that a vaccine that stimulates the body to produce more CD8 T-cells could be an effective way to fight flu viruses, including new strains that cross over into people from birds and pigs.
"New strains of flu are continuously emerging, some of which are deadly, and so the Holy Grail is to create a universal vaccine that would be effective against all strains of flu," study leader Professor Ajit Lalvani said in an Imperial College London news release.
"The immune system produces these CD8 T-cells in response to usual seasonal flu. Unlike antibodies, they target the core of the virus, which doesn't change, even in new pandemic strains. The 2009 pandemic provided a unique natural experiment to test whether T-cells could recognize, and protect us against, new strains that we haven't encountered before and to which we lack antibodies," Lalvani explained.
"Our findings suggest that by making the body produce more of this specific type of CD8 T-cell, you can protect people against symptomatic illness. This provides the blueprint for developing a universal flu vaccine."
Lalvani added: "We already know how to stimulate the immune system to make CD8 T-cells by vaccination. Now that we know these T-cells may protect, we can design a vaccine to prevent people getting symptoms and transmitting infection to others. This could curb seasonal flu annually and protect people against future pandemics."

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