Staphylococcus aureus phenotype switching ...

ScienceDaily (Jan. 26, 2011)

New research in Staphylococcus aureus, a bacterium responsible for severe chronic infections worldwide, shows how bacteria have developed a strategy of hiding inside the host cell to avoid immune system and many antibacterial treatment. In a study published medical EMBO Molecular, shows like "phenotype switching" allows bacteria to adapt to environmental conditions, dormant inside host cells and become a reservoir for recurrent infection. Staphylococcus aureus is a major human pathogens can be achieved up to 70% of healthy people and can lead to conditions such as deep tissue infection, osteomyelitis, and chronic lung infections that are often difficult to treat with antibiotics. A key feature of these infections is that relapses can occur months or years after treatment are obvious. These relapses, Dr. Bettina Lffler and her team from the Institute fr Medizinische Mikrobiologie in Mnster, Germany, find related phenotype switch, changes in bacterial behavior. After infection and invasion of the host patient cells, the bacteria form small colony variants (CSN), a tiny bacterial subgroups, which can evade the immune system, and many antibiotics and grow slowly. For the microbiologist, it is difficult to detect CSN in clinical specimens as they grow slowly, often requiring several days to form and therefore can not be easily seen in the diagnosis, said Lffler. Our studies were asked two questions: the development of CSN integral part of the infectious process and that the dynamics of formation of SCV? The team performed long-term study of Staphylococcus aureus infection in cell culture systems and also analyzed tissue samples from subacute and chronic infections of humans. The study showed that in all models of infection, the bacteria that are stored in the host for several weeks after infection, which leads to the formation of colonies of SCV. It showed that KSM began to appear following infection, after the immune system was overcome, and this persistence resulted in a large variety fenotypycheskym bacteria. These studies show that Staphylococcus aureus

extreme versatile microorganisms that constantly feel that their environmental conditions and can quickly change to show them, said Lffler. The formation of strattera SCV colonies of bacterial phenotype switching strategy which is an integral part of the infectious process. This process allows bacteria to hide within host cells without causing an inflammatory reaction of the host immune system. In addition, they can be effectively protected from antibiotic treatment. This strategy means that KSM can be regarded as "dormant form" of infections that can quickly recover its full virulence and cause the patient to relapse concluded Lffler. It is of great clinical importance since it implies that targeting phenotype switching may prevent bacteria from hiding, making infection more vulnerable to host response and treatment. Recommend this story on Facebook, Twitter

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and Google +1: Other Bookmark and collaboration: History Source: above story is reprinted with are through. Note: materials may be edited for content and length. For more information, please contact the source listed above. Journal Links Lorena Tuchscherr, Eva Medina, Muzaffar Hussain, Wolfgang Vlker, Vanessa Haytmann, Silke Niemann, Dirk Holzinger, Johannes Roth, Richard A. Proctor, Karsten Becker, George Peters, Bettina Lffler. Staphylococcus aureus phenotype switching: effective strategies to avoid bacterial immune response and establish chronic infection. EMBO Molecular Medicine, 2011, DOI:

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