August 22, 2011

New Weapon For Common Hospital Infection

Researchers may have discovered an impressive new weapon in the struggle against hospital-acquired bacterial infections, Reuters is reporting. Clostridium difficile is an antibiotic-resistant bacterial infection that can cause diarrhea, colitis, the inflammation of the colon. At its worst, it can be fatal and is often spread around hospitals and medical facilities.

Tests of an experimental compound are mimicking the human defense mechanism, used by cells in the gut to neutralize harmful toxins, is showing promise in the lab and in mouse studies, and the researchers say they are already planning human clinical trials.

“This is a $3.5 billion problem in the US alone and it´s rising rapidly because of new, even more virulent strains,” said Tor Savidge of the University of Texas Medical Branch at Galveston, whose study is being published in the journal Nature Medicine.

“Between 1 to 2 percent of patients who go into the hospital will develop this.” Elderly patients being treated with antibiotics are especially vulnerable as antibiotics kill natural bacteria in the gut and allow invaders such as C. difficile to flourish.

Savidge and colleagues noticed that in order to squeeze into cells lining the intestine, toxins produced by C. difficile need to chop themselves into smaller bits. C. difficile accomplishes this through a molecular guillotine called a cysteine protease, which only becomes active when a molecule called InsP6 is present in large concentrations inside a cell.

Once inside the cell, the toxin releases its payload, killing cells that line the intestine and triggering inflammation and diarrhea.

Savidge´s team discovered is that once this process starts, the body releases neutralizing chemicals that gum up the molecular guillotine, preventing the toxins from being chopped up and damaging the cell.

Inspired by this natural mechanism, the team developed a treatment that mimics this process, shutting down the guillotine and preventing the toxin from damaging the cell. “If you shut them down before they can interact with the cell we can alleviate the disease.”

Mice with C. difficile who were treated with the drug became less ill and were more likely to survive their infections than untreated mice.

Currently, patients who get these infections are treated with antibiotics, which contributes to the problem of antibiotic resistance, however this new treatment would simply keep the toxins from making people sick, allowing the normal, protective gut bacteria to remain intact.

“This may prove to be an alternative to antibiotics,” Savidge said, but much more work is needed. “This needs to be confirmed with additional studies and additional groups will need to confirm it as well.”


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