Effective removal of staphylococcal biofilms on various food contact surfaces by Staphylococcus aureus phage endolysin LysCSA13.

Staphylococcal biofilms are recognized as a significant problem in the food industry because of their high resistance to antibiotics, and the use of bacteriophages or endolysins has been regarded as a promising alternative to antibiotics. In this study, LysCSA13, an endolysin from S. aureus virulent bacteriophage CSA13, was cloned and characterized. LysCSA13 consists of an enzymatic active domain and a cell wall binding domain. LysCSA13 showed strong antimicrobial activity against staphylococcal strains at pH 7.0-9.0, 4.0-37.0 °C and in the presence of Ca2+ and Mn2+. In addition, a high efficacy of LysCSA13 in removing staphylococcal biofilms was observed on various surfaces, including polystyrene, glass and stainless steel, displaying an approximately 80-90% decrease in biofilm mass. Furthermore, 300 nM of LysCSA13 effectively removed staphylococcal sessile cells formed on stainless steel and glass by 1-3 log units compared with the untreated control. Scanning electron microscopy analysis visualized the effective deformation and removal of cells embedded in the biofilm matrix. The results indicate that LysCSA13 can effectively control staphylococcal planktonic cells and biofilms regardless of the contact surface matrix and suggest the possible use of LysCSA13 as a promising biocontrol agent in various food processing environments.