Sub-Inhibitory Concentrations of Mupirocin Stimulate Staphylococcus aureus Biofilm Formation by Up-regulating cidA.

Sub-Inhibitory Concentrations of Mupirocin Stimulate Staphylococcus aureus Biofilm Formation by Up-regulating cidA. Antimicrob Agents Chemother. 2020 Jan 13;: Authors: Jin Y, Guo Y, Zhan Q, Shang Y, Qu D, Yu F Abstract Previous studies have shown that the administration of antibiotics at sub-inhibitory concentrations stimulates biofilm formation by the majority of MRSA strains. Here, we investigated the effect of sub-inhibitory mupirocin concentrations on biofilm formation by the community-associated (CA) mupirocin-sensitive MRSA strain USA300 and highly mupirocin-resistant clinical S. aureus SA01-SA05 isolates. We found that mupirocin increased the ability of MRSA cells to attach to surfaces and form biofilms. Confocal laser scanning microscopy (CLSM) demonstrated that mupirocin treatment promoted thicker biofilm formation, which also correlated with the production of extracellular DNA (eDNA). Furthermore, RT-qPCR results revealed that this effect was largely due to the involvement of holin-/antiholin-like proteins (encoded by the cidA gene), which are responsible for modulating cell death and lysis during biofilm development. We found that cidA expression levels significantly increased 6.05-35.52 fold (P < 0.01) on mupirocin administration. We generated a cidA-deficient mutant of the USA300 S. aureus strain. Exposure of the ΔcidA mutant to mupirocin did not result in thicker biofilm formation compared with that in the parent st...
Source: Antimicrobial Agents and Chemotherapy - Category: Microbiology Authors: Tags: Antimicrob Agents Chemother Source Type: research