Poly-N-acetyl-glucosamine as a Mediator of Bacterial Biofilm Formation
Kimberly K. Jefferson
from: Bacterial Polysaccharides: Current Innovations and Future Trends (Edited by: Matthias Ullrich). Caister Academic Press, U.K. (2009)
A number of evolutionarily disparate bacterial species synthesize and secrete a β-(1,6)-linked polymer of N-acetylglucosamine. This polysaccharide is known as polysaccharide intercellular adhesin (PIA), PNAG, or PGA depending on the species that produces it, but all are biochemically similar. The conservation of this polysaccharide is a tribute to its success as a virulence factor and it plays dual roles in this capacity. It is an essential scaffold in bacterial biofilms and also plays a role in immune evasion by interfering with opsonophagocytosis. It is loosely associated with the bacterial cell surface and is therefore not considered a capsular polysaccharide. In addition, PIA/PNAG/PGA is more structurally simplistic than most capsular polysaccharides. Nonetheless, the role of this polysaccharide in virulence in such species as Staphylococcus aureus, S. epidermidis, Escherichia coli, and Actinobacillus actinomycetemcomitans is clear, and advances in our understanding of its synthesis and structure may lead to its use as a therapeutic or vaccine target read more ...