Equivalent effect of extracellular proteins and polysaccharides on biofilm formation by clinical isolates of Staphylococcus lugdunensis

Biofilm formation by Staphylococcus lugdunensis involves formation of an extracellular matrix; however, the identity of the constituents responsible for the structure of biofilms fabricated by different clinical strains is largely unclear. Here, biofilms produced by 24 clinical isolates of S. lugdunensis were characterized. The optimal medium for S. lugdunensis was selected, and the biofilm-forming capacity was assessed. Extracelullar polymeric substances (EPS) contributing to biofilm robustness were determined by evaluating the susceptibility of biofilms to EPS-degrading agents using field emission scanning electron microscopy and confocal laser scanning microscopy. Biofilm formation by the clinical isolates of S. lugdunensis was augmented by glucose supplementation. Further, extracellular DNA (eDNA), proteins, and polysaccharides were present in the 24 clinical isolates. Proteins and polysaccharides were the most common components within the S. lugdunensis biofilms, whereas the eDNA content was marginal in biofilm formation. Therefore, proteins and polysaccharides within biofilms may be used as the primary targets for developing eradication strategies to prevent S. lugdunensis biofilm formation.