title: Eradication of enterococci biofilms by lactic acid alone and combined with chlorhexidine and cetrimide.
abstract: OBJECTIVE
  The antimicrobial activity of lactic acid (LA) alone or in combination with chlorhexidine (CHX) and cetrimide (CTR) against three Enterococcus faecalis strains, E. faecalis ATCC 29212, E. faecalis EF-D1 and E. faecalis U-1765, one Enterococcus durans strain and one dual-species biofilm was investigated.
  
  
  METHODS
  The irrigating solutions tested were 20%, 15%, 10%, 5% and 2.5% LA, alone and in combination with 2% CHX and with 0.2% CTR. The biofilms were grown in the MBECTM high-throughput device for 24 hours and exposed to the solutions for 30 seconds and 1 minute. "Eradication" was defined as 100% bacterial kill.
  
  
  RESULTS
  Twenty percent LA eradicated all enterococci biofilms after 30 seconds contact time. The association of LA+0.2% CTR achieved better results than LA alone, in contrast with the results obtained using LA+2% CHX. E. durans was eradicated by all the tested solutions at 1 minute. The dual-species biofilm, E. faecalis ATCC 29212+E. durans, gave intermediate values of the pure cultures.
  
  
  CONCLUSIONS
  LA is capable of eradicating enterococci biofilm at a concentration of 20%. The combination of lower concentrations with 0.2% CTR achieved eradication after 1 minute.
authors.affiliation: Department of Microbiology, School of Dentistry, University of Granada, Campus de Cartuja, Colegio Máximo s/n, E-18071, Granada, Spain. mtarias@ugr.es
authors.forename: María-Teresa
authors.initials: MT
authors.lastname: Arias-Moliz
authors.forename: Pilar
authors.initials: P
authors.lastname: Baca
authors.forename: Santiago
authors.initials: S
authors.lastname: Ordóñez-Becerra
authors.forename: María-Paloma
authors.initials: MP
authors.lastname: González-Rodríguez
authors.forename: Carmen-María
authors.initials: CM
authors.lastname: Ferrer-Luque
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D018441:Biofilms / Q000187:drug effects*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000008:administration & dosage*; D002710:Chlorhexidine / Q000008:administration & dosage*; D004359:Drug Therapy, Combination; D016983:Enterococcus / Q000187:drug effects*; D019344:Lactic Acid / Q000008:administration & dosage*
chemical_list: D000891:Anti-Infective Agents, Local; D002593:Cetrimonium Compounds; D019344:Lactic Acid; D002710:Chlorhexidine; D000077286:Cetrimonium