Enhanced production of exopolysaccharide matrix and biofilm by a menadione-auxotrophic Staphylococcus aureus small-colony variant.
The role of Staphylococcus aureus small-colony variants (SCVs) in the pathogenesis of biofilm-associated infections remains unclear. This study investigated the mechanism behind increased biofilm-forming potential of a menadione-auxotrophic Staphylococcus aureus SCV compared with the wild-type parental strain, as recently reported by our laboratory. SCVs displayed an autoaggregative phenotype, with a greater amount of polysaccharide intercellular adhesin (PIA), significantly reduced tricarboxylic acid cycle activity and a decreased susceptibility to aminoglycosides and cell-wall inhibitors compared with wild-type. The biofilms formed by the SCV were highly structured, consisting of large microcolonies separated by channels, and contained more biomass as well as significantly more PIA than wild-type biofilms. The surface hydrophobicity of the two phenotypes was similar. Thus, the autoaggregation and increased biofilm-forming capacity of menadione-auxotrophic Staphylococcus aureus SCVs in this study was related to the enhanced production of PIA in these variants.
Singh
Rachna
R
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
Ray
Pallab
P
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
Das
Anindita
A
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
Sharma
Meera
M
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
D018829:Adhesins, Bacterial / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D002952:Citric Acid Cycle; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008826:Microbial Sensitivity Tests; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D024483:Vitamin K 3 / Q000378:metabolism*
D018829:Adhesins, Bacterial; D000900:Anti-Bacterial Agents; D011135:Polysaccharides, Bacterial; D024483:Vitamin K 3