title: pH required to kill Enterococcus faecalis in vitro.
abstract: Enterococcus faecalis tolerates highly alkaline environments, yet the exact pH required for killing E. faecalis is not known. This study tests growth at 0.5 increments from pH 9.5 to 12. Twelve culture tubes were used in each group. Positive growth was measured using turbidity, a visual scale, and a spectrophotometer. At 24 h, growth was observed in all tubes at pH 9.5 and 10. At 48 h, all pH 10.5 tubes showed growth. At 72 h, six of the pH 11 tubes showed growth. After 7 days, five of the remaining pH 11 tubes were positive. No growth occurred in any of the pH 11.5 or pH 12 tubes. Apparently, pH 10.5 to 11.0 retards growth of E. faecalis, whereas no tubes showed growth at pH 11.5 or greater.
authors.affiliation: Department of Endodontics and Pulp Biology, School of Dentistry, University of Alabama at Birmingham, 35294-0007, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: McHugh
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Suzanne
authors.initials: S
authors.lastname: Michalek
authors.forename: Paul D
authors.initials: PD
authors.lastname: Eleazer
mesh_terms: D013293:Enterococcus faecalis / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration