Antimicrobial factors effects on biofilm formation in Staphylococcus aureus

Abstract

We determined the disinfectant effects of benzalkonium chloride (BC) and Savo (SV), a chlorine compound, on the biofilm and planktonic cells in 23 strains S. aureus mainly food isolates. The biofilm formation was performed in a model system using microtiter polystyrene plates COSTAR 3797 in trypton-soy broth with 1% glucose at 30°C. Benzalkonium chloride (BC) at 125 mg/l, applied directly on 24 h old biofilm, was able to remove the biofilm matrix in 21 strains, and to stop the reproduction of the biofilm cells in 23 strains. BC at the concentration of 125 mg/l was lethal to planktonic cells, coincubated for 24 h or treated for 10 minutes. None of the strains studied was able to grow in SV at 1X recommended concentration, while the safety lethal concentration for planktonic cells treated for 10 min was 4X. The application of 4X concentration SV into the 24 h old suspension removed the biofilm matrix in all strains and devitalised the biofilm cells in 10 strains and inhibited the viability in 13 strains by 70%.

Keywords

• staphylococcus aureus
• biofilm
• planktonic cells
• disinfectants
• benzalkonium chloride
• savo