title: Farnesol in combination with N-acetylcysteine against Staphylococcus epidermidis planktonic and biofilm cells.
abstract: Staphylococcus epidermidis is the most frequent cause of nosocomial sepsis and catheter-related infections, in which biofilm formation is considered to be the main virulence mechanism. In biofilm environment, microbes exhibit enhanced resistance to antimicrobial agents. This fact boosted the search of possible alternatives to antibiotics. Farnesol and N-acetylcysteine (NAC) are non-antibiotic drugs that have demonstrated antibacterial properties. In this study, the effect of farnesol and NAC isolated or in combination (farnesol+NAC) was evaluated. NAC at 10 × MIC caused a total cell death in planktonic cells. On the other hand, S. epidermidis biofilms exhibited 4 log reduction in viable cell number after a 24h treatment with NAC at the former concentration. Our results demonstrated that there was a higher CFU log reduction of S. epidermidis planktonic cells when farnesol was combined with NAC at 1 × MIC relatively to each agent alone. However, these results were not relevant because NAC alone at 10 × MIC was always the condition which gave the best results, having a very high killing effect on planktonic cells and a significant bactericidal effect on biofilm cells. This study demonstrated that no synergy was observed between farnesol and NAC. However, the pronounced antibacterial effect of NAC against S. epidermidis, on both lifestyles, indicates the use of NAC as a potential therapeutic agent in alternative to antibiotics.
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho , Campus de Gualtar, 4710-057 , Braga, Portugal.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Gomes
authors.forename: Bruna
authors.initials: B
authors.lastname: Leite
authors.forename: Pilar
authors.initials: P
authors.lastname: Teixeira
authors.forename: Joana
authors.initials: J
authors.lastname: Azeredo
authors.forename: Rosário
authors.initials: R
authors.lastname: Oliveira
keywords: N- acetylcysteine.; Nosocomial infection; Staphylococci; biofilm; farnesol
references.citation: Ann Clin Microbiol Antimicrob. 2009 Apr 29;8:13
references.pmid: 19402910
references.citation: J Infect Dis. 2004 Oct 15;190(8):1498-505
references.pmid: 15378444
references.citation: Appl Environ Microbiol. 2003 Aug;69(8):4814-22
references.pmid: 12902275
references.citation: Antimicrob Agents Chemother. 2006 Apr;50(4):1463-9
references.pmid: 16569866
references.citation: J Clin Microbiol. 2003 Jan;41(1):506-8
references.pmid: 12517908
references.citation: J Basic Microbiol. 2009 Aug;49(4):363-70
references.pmid: 19219902
references.citation: Curr Microbiol. 2009 Aug;59(2):118-22
references.pmid: 19365686
references.citation: Nat Rev Microbiol. 2009 Aug;7(8):555-67
references.pmid: 19609257
references.citation: Int J Antimicrob Agents. 2006 Aug;28 Suppl 1:S14-20
references.pmid: 16829054
references.citation: J Orthop Res. 2009 Oct;27(10):1361-5
references.pmid: 19396814
references.citation: Clin J Am Soc Nephrol. 2008 Nov;3(6):1610-4
references.pmid: 18667743
references.citation: J Antimicrob Chemother. 1997 May;39(5):643-6
references.pmid: 9184365
references.citation: J Antimicrob Chemother. 2001 Dec;48(6):793-801
references.pmid: 11733463
references.citation: Microbes Infect. 2007 Sep;9(11):1376-83
references.pmid: 17890122
references.citation: J Antimicrob Chemother. 2007 Mar;59(3):425-32
references.pmid: 17242033
references.citation: Appl Environ Microbiol. 2005 Dec;71(12):8677-82
references.pmid: 16332862
references.citation: J Infect Dis. 1991 Mar;163(3):534-41
references.pmid: 1995727
references.citation: Clin Microbiol Infect. 2009 Mar;15(3):238-44
references.pmid: 19196261
references.citation: J Antimicrob Chemother. 2005 Aug;56(2):331-6
references.pmid: 15980094
references.citation: J Clin Pathol. 2009 Dec;62(12):1112-6
references.pmid: 19640858
references.citation: Antimicrob Agents Chemother. 2007 Apr;51(4):1556-8
references.pmid: 17220399