Destruction of planktonic, adherent and biofilm cells of Staphylococcus epidermidis using a gliding discharge in humid air
Résumé
AIMS : To determine the efficiency of an electric discharge of the gliding arc type for the destruction of Staphylococcus epidermidis planktonic, adherent and biofilm cells.
METHODS AND RESULTS : Bacterial cells were treated in humid air and at atmospheric pressure by a nonthermal quenched plasma of the glidarc type. The kinetics of destruction (followed by plating) were modelled by an Add-inn for Microsoft Excel, GInaFiT. For planktonic cells, log-linear destruction was obtained, whereas biphasic kinetics were observed for sessile cells. An increased resistance of biofilm cells was observed: the reduction of 6 logarithm units of the population was obtained in 15, 30 and 70 min for planktonic, adherent and biofilm cells, respectively. The experiments also show that the cells destruction did not depend on the adhesion surface but was governed by the gap between the target and the plasma source.
CONCLUSION : The complete destruction of planktonic, adherent and more resistant biofilm cells of Staph. epidermidis is achieved by a glidarc air plasma at atmospheric pressure.
SIGNIFICANCE AND IMPACT OF THE STUDY : The glidarc plasma technology is a promising candidate among the emerging nonthermal techniques for decontamination, as it can destroy even biofilms that are known as particularly resistant to various antimicrobials.