Modulation of Staphylococcus aureusBiofilm Matrix by Subinhibitory Concentrations of Clindamycin

Autor: Schilcher, Katrin, Andreoni, Federica, Dengler Haunreiter, Vanina, Seidl, Kati, Hasse, Barbara, Zinkernagel, Annelies S.
Zdroj: Antimicrobial Agents and Chemotherapy; July 2016, Vol. 60 Issue: 10 p5957-5967, 11p
Abstrakt: ABSTRACTStaphylococcus aureusbiofilms are extremely difficult to treat. They provide a protected niche for the bacteria, rendering them highly recalcitrant toward host defenses as well as antibiotic treatment. Bacteria within a biofilm are shielded from the immune system by the formation of an extracellular polymeric matrix, composed of polysaccharides, extracellular DNA (eDNA), and proteins. Many antibiotics do not readily penetrate biofilms, resulting in the presence of subinhibitory concentrations of antibiotics. Here, we show that subinhibitory concentrations of clindamycin triggered a transcriptional stress response in S. aureusvia the alternative sigma factor B (σB) and upregulated the expression of the major biofilm-associated genes atlA, lrgA, agrA, the psmgenes, fnbA, and fnbB. Our data suggest that subinhibitory concentrations of clindamycin alter the ability of S. aureusto form biofilms and shift the composition of the biofilm matrix toward higher eDNA content. An understanding of the molecular mechanisms underlying biofilm assembly and dispersal in response to subinhibitory concentrations of clinically relevant antibiotics such as clindamycin is critical to further optimize antibiotic treatment strategies of biofilm-associated S. aureusinfections.
Databáze: Supplemental Index