title: Phenotypic Modifications in Staphylococcus aureus Cells Exposed to High Concentrations of Vancomycin and Teicoplanin.
abstract: Bacterial cells are known to change the fatty acid (FA) composition of the phospholipids as a phenotypic response to environmental conditions and to the presence of toxic compounds such as antibiotics. In the present study, Staphylococcus aureus cells collected during the exponential growth phase were challenged with 50 and 100 mg/L of vancomycin and teicoplanin, which are concentrations high enough to kill the large majority of the cell population. Colony-forming unit counts showed biphasic killing kinetics, typical for persister cell enrichment, in both antibiotics and concentrations tested. However, fluorescence microscopy showed the existence of viable but non-culturable (VBNC) cells in a larger number than that of possible persister cells. The analysis of the FA composition of the cells showed that, following antibiotic exposure up to 6 h, the survivor cells have an increased percentage of saturated FAs, a significant reduced percentage of branched FAs and an increased iso/anteiso branched FA ratio when compared to cells exhibiting a regular phenotype. This should result in lower membrane fluidity. However, cells exposed for 8-24 h presented an increased branched/saturated and lower iso/anteiso branched FA ratios, and thus increased membrane fluidity. Furthermore, the phenotypic changes were transmitted to daughter cells grown in drug-free media. The fact that VBNC cells presented nearly the same FA composition as those obtained after cell growth in drug-free media, which could only be the result of growth of persister cells, suggest that VBNC and persister phenotypes share the same type of response to antibiotics at the lipid level.
authors.affiliation: iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa Lisbon, Portugal.
authors.forename: Fábio D A
authors.initials: FD
authors.lastname: Gonçalves
authors.affiliation: iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa Lisbon, Portugal.
authors.forename: Carla C C R
authors.initials: CC
authors.lastname: de Carvalho
keywords: Staphylococcus aureus; persistent infection; stress response; teicoplanin; vancomycin; viable but non-culturable cells
references.citation: Nucleic Acids Res. 2015 Jul 1;43(W1):W251-7
references.pmid: 25897128
references.citation: Science. 2004 Sep 10;305(5690):1622-5
references.pmid: 15308767
references.citation: FEMS Immunol Med Microbiol. 2011 Nov;63(2):236-47
references.pmid: 22077227
references.citation: BMC Microbiol. 2013 Feb 04;13:25
references.pmid: 23379956
references.citation: Clin Microbiol Rev. 1998 Apr;11(2):318-40
references.pmid: 9564566
references.citation: PLoS Genet. 2013;9(1):e1003123
references.pmid: 23300474
references.citation: Biochem J. 1971 Aug;123(5):789-803
references.pmid: 5124386
references.citation: Antibiotics (Basel). 2014 Oct 13;3(4):461-92
references.pmid: 25419466
references.citation: Curr Opin Microbiol. 2011 Oct;14(5):593-8
references.pmid: 21937262
references.citation: Science. 1999 May 21;284(5418):1318-22
references.pmid: 10334980
references.citation: Appl Environ Microbiol. 2008 Oct;74(19):5882-90
references.pmid: 18689519
references.citation: Antimicrob Agents Chemother. 2008 Aug;52(8):2718-26
references.pmid: 18519731
references.citation: Microb Ecol. 1982 Dec;8(4):313-23
references.pmid: 24226049
references.citation: Clin Infect Dis. 2009 Aug 1;49(3):325-7
references.pmid: 19569969
references.citation: Antimicrob Agents Chemother. 1995 Mar;39(3):781-5
references.pmid: 7793894
references.citation: Clin Microbiol Rev. 1990 Jul;3(3):280-91
references.pmid: 2143434
references.citation: Antimicrob Agents Chemother. 2001 Apr;45(4):999-1007
references.pmid: 11257008
references.citation: Front Public Health. 2014 Jul 31;2:103
references.pmid: 25133139
references.citation: PLoS One. 2014 Sep 16;9(9):e107426
references.pmid: 25226591
references.citation: J Microbiol. 2004 Jun;42(2):69-73
references.pmid: 15357297
references.citation: Curr Med Res Opin. 2010 Mar;26(3):571-88
references.pmid: 20055750
references.citation: Appl Microbiol Biotechnol. 2009 Feb;82(2):311-20
references.pmid: 19096838
references.citation: Clin Microbiol Infect. 2004 Jan;10 (1):62-9
references.pmid: 14706088
references.citation: Eur J Clin Microbiol Infect Dis. 1989 Nov;8(11):943-50
references.pmid: 2532132
references.citation: FEMS Microbiol Rev. 2009 Jul;33(4):704-17
references.pmid: 19207742
references.citation: Trends Microbiol. 2015 Jan;23(1):7-13
references.pmid: 25449050
references.citation: Nat Rev Microbiol. 2007 Jan;5(1):48-56
references.pmid: 17143318
references.citation: Annu Rev Microbiol. 2010;64:357-72
references.pmid: 20528688
references.citation: Res Microbiol. 2012 Feb;163(2):125-36
references.pmid: 22146587
references.citation: PLoS One. 2014 Feb 21;9(2):e88660
references.pmid: 24586365
references.citation: Proc Natl Acad Sci U S A. 1974 Feb;71(2):522-5
references.pmid: 4360948
references.citation: Virulence. 2013 May 15;4(4):273-83
references.pmid: 23563389
references.citation: PLoS One. 2012;7(1):e29573
references.pmid: 22253738
references.citation: J Infect Chemother. 2013 Feb;19(1):24-33
references.pmid: 22821354
references.citation: J Bacteriol. 1968 Jun;95(6):2198-209
references.pmid: 5669897
references.citation: FEMS Microbiol Lett. 2009 Aug;297(1):73-9
references.pmid: 19508279
references.citation: Antimicrob Agents Chemother. 2008 Jan;52(1):269-78
references.pmid: 17954690
references.citation: J Antibiot (Tokyo). 1995 Nov;48(11):1292-8
references.pmid: 8557571
references.citation: J Mol Microbiol Biotechnol. 2012;22(4):235-44
references.pmid: 22986269
references.citation: Nature. 2011 May 12;473(7346):216-20
references.pmid: 21562562
references.citation: Philos Trans R Soc Lond B Biol Sci. 1995 Nov 29;350(1332):133-41
references.pmid: 8577857
references.citation: Antibiotiki. 1983 Jun;28(6):412-7
references.pmid: 6881950
references.citation: J Med Microbiol. 2009 Aug;58(Pt 8):1067-73
references.pmid: 19528167
references.citation: Science. 2013 Jan 4;339(6115):91-5
references.pmid: 23288538
references.citation: J Appl Bacteriol. 1995 Oct;79(4):399-408
references.pmid: 7592133
references.citation: J Microbiol. 2005 Feb;43 Spec No:93-100
references.pmid: 15765062
references.citation: Nat Rev Microbiol. 2008 Mar;6(3):222-33
references.pmid: 18264115
references.citation: PLoS One. 2013 May 13;8(5):e62814
references.pmid: 23675428
references.citation: Microb Cell Fact. 2011 Aug 30;10 Suppl 1:S14
references.pmid: 21995592
references.citation: PLoS Pathog. 2011 Jul;7(7):e1002121
references.pmid: 21829345
references.citation: Front Cell Infect Microbiol. 2014 Oct 22;4:148
references.pmid: 25374846
references.citation: J Hosp Infect. 1986 Mar;7 Suppl A:79-83
references.pmid: 2871101
references.citation: Appl Environ Microbiol. 1994 Dec;60(12):4440-4
references.pmid: 7811084
references.citation: Antimicrob Agents Chemother. 2010 Dec;54(12):5222-33
references.pmid: 20837752
references.citation: Curr Opin Microbiol. 2007 Feb;10(1):30-8
references.pmid: 17215163
references.citation: Evol Appl. 2012 Feb;5(2):192-201
references.pmid: 25568041
references.citation: J Cyst Fibros. 2011 Sep;10(5):298-306
references.pmid: 21719362
references.citation: Neth J Med. 2011 Sep;69(9):379-83
references.pmid: 21978980
references.citation: Front Microbiol. 2014 Jun 02;5:258
references.pmid: 24917854
references.citation: Infect Immun. 2015 Nov;83(11):4194-203
references.pmid: 26283335
references.citation: Antimicrob Agents Chemother. 2013 Sep;57(9):4398-409
references.pmid: 23817376
references.citation: Antimicrob Agents Chemother. 2013 Jul;57(7):3230-9
references.pmid: 23629720
references.citation: J Bacteriol. 2004 Dec;186(24):8172-80
references.pmid: 15576765
references.citation: J Bacteriol. 1970 Oct;104(1):323-30
references.pmid: 5473899