Phenol-soluble modulin

Phenol-soluble modulins are a family of protein toxins that are soluble in phenols and produced by CA-MRSA, which are thought to be the cause of severe infections. Non-methicillin resistant bacteria were not found to produce these toxins. Although the toxins are produced in all Methicillin-resistant Staphylococcus aureus strains, the more virulent CA-MRSA strains are typically associated with higher production. Genetic analysis demonstrated that the PSM-alpha protein, product of the psm-alpha gene cluster, was associated with the enhanced virulence enhanced destruction of white blood cells, presumably the key to the higher infectivity. Expression of the psm-alpha genes appeared to vary, dependent upon unknown factors specific to each particular infection.