title: Susceptibility of Enterococcus faecalis biofilm to antibiotics and calcium hydroxide.
abstract: The purpose of this study was to investigate the antimicrobial efficacy of six groups of antibiotics and calcium hydroxide against Enterococcus faecalis biofilm in a membrane filter model. Two-day-old E. faecalis (ATCC 29212) biofilm was exposed to ampicillin, co-trimoxazole, erythr omycin, oxytetracycline, vancomycin, vancomycin followed by gentamicin, Ca(OH)(2), and phosphate-buffered saline (control). After 1 h of exposure, the antimicrobial activity was neutralized by washing each disc five times in PBS, and then the colony-forming units of the remaining viable bacteria on each disc were counted. The results revealed that only erythromycin, oxytetracycline and Ca(OH)2 showed 100% biofilm kill. An ANOVA with a Bonferroni post hoc test (P < 0.05) detected significant differences among the test agents, except in the ampicillin group versus the co-trimoxazole group. It is concluded that erythromycin, oxytetracycline and Ca(OH)2 are 100% effective in eliminating E. faecalis biofilm, whereas ampicillin, co-trimoxazole, vancomycin, and vancomycin followed by gentamicin are ineffective.
authors.affiliation: Department of General Dental Practice and Oral and Maxillofacial Imaging, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia. chaiwl@um.edu.my
authors.forename: Wen L
authors.initials: WL
authors.lastname: Chai
authors.forename: Hassan
authors.initials: H
authors.lastname: Hamimah
authors.forename: Soo C
authors.initials: SC
authors.lastname: Cheng
authors.forename: Atiya A
authors.initials: AA
authors.lastname: Sallam
authors.forename: Mariam
authors.initials: M
authors.lastname: Abdullah
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002126:Calcium Hydroxide / Q000494:pharmacology*; D015169:Colony Count, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D012387:Root Canal Filling Materials / Q000494:pharmacology*; D012388:Root Canal Irrigants / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D002126:Calcium Hydroxide