In Vitro Antimicrobial Effect of a Cold Plasma Jet against Enterococcus faecalis Biofilms

Abstract EN

The hypothesis that a cold plasma jet has the antimicrobial effect against Enterococcus faecalis biofilms was tested in vitro.

27 hydroxyapatite discs were incubated with E.

faecalis for six days to form a monoculture biofilm on the disc surface.

The prepared substrata were divided into three groups: the negative control, the positive control (5.25% NaOCl solution), and the plasma treatment group.

Resultant colony-forming unit counts were associated with observations of bacterial cell morphology changes using scanning electron microscopy (SEM).

Treatment of E.

faecalis biofilm with the plasma and 5.25% NaOCl for 5 min resulted in 93.1% and 90.0% kill (P<0.0001), respectively.

SEM detected that nearly no intact bacteria were discernible for the plasma-exposed HA disc surfaces.

The demonstrated bactericidal effect of the plasma with direct surface contact may be due to the enhanced oxidation by the locally produced reactive plasma species.