The Relationship between Methicillin Resistance and Biofilm Composition in Staphylococcus Aureus |Biomedgrid

Staphylococcus aureus (SA) is a common commensal bacterium and opportunistic pathogen in humans. Antibiotic-resistant SA strains, such as methicillin-resistant Staphylococcus aureus (MRSA), have become increasingly prevalent in recent years. Another aspect of SA that makes it a successful pathogen is its ability to form biofilms. SA biofilms aid in the invasion of host tissues, and biofilms can form on the surfaces of implanted medical devices, leading to serious, persistent, and sometimes life-threatening infections. Biofilms also prevent effective antibiotic treatment and promote evasion of the host immune response. The biofilms formed by MRSA and by methicillin-susceptible SA (MSSA) are typically quite different, with MSSA biofilms usually composed of polysaccharides and MRSA biofilms typically composed of extracellular proteins and DNA. Interestingly, transfer of the mecA gene (confers resistance to methicillin) alone to a MSSA strain can result in a profound change in biofilm composition to reflect a MRSA biofilm phenotype. The mechanism for this switch in biofilm phenotypes is still an area of active investigation and may yield insights into how to combat this important human pathogen.