Phenol-soluble modulin

Phenol-soluble modulins (PSMs) are a family of protein toxins that are soluble in phenols that are produced by staphylococcus bacteria. In all species of Staphylococcus, including Methicillin-resistant Staphylococcus Aureus (MRSA), they are encoded within the core genome and are an important virulence factor. As they are part of the core genome and not found on mobile genetic elements, all species of Staphylococcus carry these genes. Phenol-soluble modulins (PSMs) are a family of protein toxins that are soluble in phenols that are produced by staphylococcus bacteria. In all species of Staphylococcus, including Methicillin-resistant Staphylococcus Aureus (MRSA), they are encoded within the core genome and are an important virulence factor. As they are part of the core genome and not found on mobile genetic elements, all species of Staphylococcus carry these genes. MRSA production of PSMs is thought to be a possible cause of severe infections. PSM production is higher in community-acquired MRSA (CA-MRSA) than in healthcare-associated MRSA (HA-MRSA), and consequently CA-MRSA associated osteomyelitis is more severe than HA-MRSA associated osteomyelitis. Genetic analysis demonstrated that the PSM-alpha protein, product of the psm-alpha gene cluster, was associated with enhanced virulence and enhanced destruction of white blood cells, presumably the key to the higher infectivity. However, expression of the psm-alpha genes appeared to vary, dependent upon unknown factors specific to each particular infection.