Scientists uncover how superbug Staph aureus resists our natural defensesMarch 25, 2008Researchers at the University of Washington have uncovered how the bacterium Staphylococcus aureus, including the notorious MRSA (methicillin-resistant Staph aureus) "superbug" strains, resists our body's natural defenses against infection. The work, which was featured on the cover of the March 21 issue of Science, could lead to new ways to fight the bacteria. Dr. Ferric Fang, UW professor of laboratory medicine and microbiology, and his UW colleagues Dr. Anthony Richardson and Dr. Stephen Libby set out to determine what makes Staph aureus a better pathogen than other bacteria. They focused on a chemical compound called nitric oxide (NO), a natural antibiotic that our cells excrete to protect us from pathogens. For most bacteria, NO creates an environment that keeps invading microbes from undergoing respiration or fermentation, vital chemical processes that allow bacteria to grow. The researchers found that Staph aureus has a mechanism that allows it to produce lactic acid in the presence of NO, which allows it to maintain its chemical balance and keep growing and thriving in the harsh host environment. When Staph aureus is exposed to NO, it produces the novel enzyme responsible for lactic acid production, along with another enzyme that converts NO to non-toxic products. NO is commonly found in the nose and nasal passages, and is meant to protect people against disease-causing microbes. But Staph aureus is commonly found in the nose despite the presence of NO, the researchers explained. When the researchers modified Staph aureus to take away its ability to make lactic acid, the bacteria could no longer tolerate NO. The modified bacteria also lost their ability to survive in host immune cells and cause lethal disease in mice. "MRSA has become an enormous public health problem, by causing both hospital- and community-acquired infections," explained Fang. "Staph aureus has already colonized about one-third of the world's population, so traditional antibiotics will probably not be the complete answer to the MRSA problem." However, the researchers added, trying to make Staph aureus more susceptible to our natural defenses might lead to new strategies to de-colonize the population and prevent staphylococcal infections. University of Washington |
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| Related Staph Aureus Current Events and Staph Aureus News Articles NYU scientists discover dangerous new method for bacterial toxin transfer Scientists have discovered a new way for bacteria to transfer toxic genes to unrelated bacterial species, a finding that raises the unsettling possibility that bacterial swapping of toxins and other disease-aiding factors may be more common than previously imagined. Oral vitamin D may help prevent some skin infections A study led by researchers at the University of California, San Diego School of Medicine suggests that use of oral Vitamin D supplements bolsters production of a protective chemical normally found in the skin, and may help prevent skin infections that are a common result of atopic dermatitis, the most common form of eczema. Turning on cell-cell communication wipes out staph biofilms University of Iowa researchers have succeeded in wiping out established biofilms of Staphylococcus aureus (staph) by hijacking one of the bacteria's own regulatory systems. Although the discovery is not ready for clinical application, the findings offer insight into a dispersal mechanism for staph biofilms and might help identify therapeutic targets. Researchers seek to make cavity-causing bacteria self-destruct Bacteria that eat sugar and release cavity-causing acid onto teeth may soon be made dramatically more vulnerable to their own acid. Researchers have identified key genes and proteins that, if interfered with, can take away the ability of a key bacterial species to thrive as its acidic waste builds up in the mouth. Winemaking waste proves effective against disease-causing bacteria in early studies A class of chemicals in red wine grapes may significantly reduce the ability of bacteria to cause cavities, according to a study published recently in the Journal of Agricultural and Food Chemistry. More Staph Aureus Current Events and Staph Aureus News Articles |
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