Phase Variation of Poly-N-Acetylglucosamine Expression in Staphylococcus aureus

• DOI: 10.1371/journal.ppat.1004292
• Publication Date: 2014-07-31T21:17:59Z
• Authors: Jamie L. Brooks; Kimberly K. Jeffe...
• Keywords: Phase variation

Polysaccharide intercellular adhesin (PIA), also known as poly-N-acetyl-β-(1-6)-glucosamine (PIA/PNAG) is an important component of Staphylococcus aureus biofilms and contributes to resistance phagocytosis. The proteins IcaA, IcaD, IcaB, IcaC are encoded within the (ica) operon synthesize PIA/PNAG. We discovered a mechanism phase variation in PIA/PNAG expression that appears involve slipped-strand mispairing. process reversible RecA-independent, involves expansion contraction simple tetranucleotide tandem repeat icaC. Inactivation results PIA/PNAG-negative phenotype. A PIA/PNAG-hyperproducing strain gained fitness advantage vitro following icaC mutation loss production. was detected two clinical isolates, suggesting under certain conditions, production may be advantageous during infection. There survival for icaC-negative harboring intact icaADB genes relative isogenic icaADBC deletion mutant. Together, these suggest inactivation mode expression, high-level carries cost, contribute bacterial fitness, by unknown mechanism, absence gene