Tips from the American Journal of Pathology.
The cytolytic toxin PVL is a CA-MRSA virulence factor that has been epidemiologically associated with the development of invasive, and sometimes fatal, pneumonia in affected patients and has therefore become a target for new therapeutics. To explore the role of PVL in invasive MRSA, Olsen et al examined both wild-type and PVL-deficient MRSA in a model of CA-MRSA pneumonia. They found no effect of PVL on virulence in MRSA-associated pneumonia, as a PVL-mutated strain caused similar lower respiratory tract pathology as a wild-type strain. These data highlight the importance of context in the pathogenesis of MRSA-associated pneumonia. Addition studies are underway by Dr. Musser and colleagues "to test the hypothesis that PVL enhances pathogenesis during influenza virus co-infection. These studies are especially important in the context of the recent global spread of a H1N1 influenza strain and widespread concerns about a detrimental effect on human health."