title: In Vitro Antimicrobial Effect of a Cold Plasma Jet against Enterococcus faecalis Biofilms.
abstract: 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.
authors.affiliation: Department of Electrical Engineering-Electrophysics, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Chunqi
authors.initials: C
authors.lastname: Jiang
authors.forename: Christoph
authors.initials: C
authors.lastname: Schaudinn
authors.forename: David E
authors.initials: DE
authors.lastname: Jaramillo
authors.forename: Paul
authors.initials: P
authors.lastname: Webster
authors.forename: J William
authors.initials: JW
authors.lastname: Costerton