Population dynamics parameters of Staphylococcus aureus strain SA113 were quantified based on growth and killing experiments with batch culture cells in rich medium. Eradication kinetics and the concomitant isolation of a subpopulation of drug-tolerant SA113 persisters upon treatment with super-minimal inhibitory concentrations of antibiotics such as ciprofloxacin, daptomycin, and tobramycin served as a basis for mathematical analyses. According to a two-state model for stochastic phenotype switching, levels of persister cells and their eradication rates were influenced by the antibiotics used for isolation, clearly indicating a heterogeneous pool of S. aureus persisters. Judging from time-dependent experiments, the persisters’ degree of drug tolerance correlated with the duration of antibiotic challenge. Moreover, cross-tolerance experiments with cells consecutively treated with two different antibiotics revealed that multi-drug tolerance is not a necessary trait of S. aureus persisters isolated by antibiotic challenge. In some cases, the results depended on the order of the two antibiotic treatments, suggesting that antibiotic tolerance may be achieved by a combination of preexisting persisters and an adaptive response to drug exposure. Counts of live cells which had endured drug treatment increased only after lag phases of at least 3 h after the shift to non-selective conditions. Thus, this study provides quantitative insights into population dynamics of S. aureus persisters with regard to antibiotic challenge.

1.
Allison KR, Brynildsen MP, Collins JJ: Heterogeneous bacterial persisters and engineering approaches to eliminate them. Curr Opin Microbiol 2011;14:593–598.
[PubMed]
2.
Balaban NQ: Persistence: mechanisms for triggering and enhancing phenotypic variability. Curr Opin Genet Dev 2011;21:768–775.
[PubMed]
3.
Balaban NQ, Merrin J, Chait R, Kowalik L, Leibler S: Bacterial persistence as a phenotypic switch. Science 2004;305:1622–1625.
[PubMed]
4.
Bigger J: Treatment of staphylococcal infections with penicillin. Lancet 1944;244:497–500.
5.
Buerger S, Spoering A, Gavrish E, Leslin C, Ling L, Epstein SS: Microbial scout hypothesis, stochastic exit from dormancy, and the nature of slow growers. Appl Environ Microbiol 2012;78:3221–3228.
[PubMed]
6.
Cataudella I, Trusina A, Sneppen K, Gerdes K, Mitarai N: Conditional cooperativity in toxin-antitoxin regulation prevents random toxin activation and promotes fast translational recovery. Nucleic Acids Res 2012, Epub ahead of print.
7.
Davidson RJ, Zhanel GG, Phillips R, Hoban DJ: Human serum enhances the postantibiotic effect of fluoroquinolones against Staphylococcus aureus. Antimicrob Agents Chemother 1991;35:1261–1263.
[PubMed]
8.
Dhar N, McKinney JD: Microbial phenotypic heterogeneity and antibiotic tolerance. Curr Opin Microbiol 2007;10:30–38.
[PubMed]
9.
Drusano GL: Antimicrobial pharmacodynamics: critical interactions of ‘bug and drug’. Nat Rev Microbiol 2004;2:289–300.
[PubMed]
10.
Dworkin J, Shah IM: Exit from dormancy in microbial organisms. Nat Rev Microbiol 2010;8:890–896.
[PubMed]
11.
Gefen O, Balaban NQ: The importance of being persistent: heterogeneity of bacterial populations under antibiotic stress. FEMS Microbiol Rev 2009;33:704–717.
[PubMed]
12.
Gefen O, Gabay C, Mumcuoglu M, Engel G, Balaban NQ: Single-cell protein induction dynamics reveals a period of vulnerability to antibiotics in persister bacteria. Proc Natl Acad Sci USA 2008;105:6145–6149.
[PubMed]
13.
Hanberger H, Nilsson LE, Maller R, Isaksson B: Pharmacodynamics of daptomycin and vancomycin on Enterococcus faecalis and Staphylococcus aureus demonstrated by studies of initial killing and postantibiotic effect and influence of Ca2+ and albumin on these drugs. Antimicrob Agents Chemother 1991;35:1710–1716.
[PubMed]
14.
Iordanescu S, Surdeanu M: Two restriction and modification systems in Staphylococcus aureus NCTC8325. J Gen Microbiol 1976;96:277–281.
[PubMed]
15.
Isaksson B, Maller R, Nilsson LE, Nilsson M: Postantibiotic effect of aminoglycosides on staphylococci. J Antimicrob Chemother 1993;32:215–222.
[PubMed]
16.
Jõers A, Kaldalu N, Tenson T: The frequency of persisters in Escherichia coli reflects the kinetics of awakening from dormancy. J Bacteriol 2010;192:3379–3384.
[PubMed]
17.
Kaldalu N, Mei R, Lewis K: Killing by ampicillin and ofloxacin induces overlapping changes in Escherichia coli transcription profile. Antimicrob Agents Chemother 2004;48:890–896.
[PubMed]
18.
Keren I, Kaldalu N, Spoering A, Wang Y, Lewis K: Persister cells and tolerance to antimicrobials. FEMS Microbiol Lett 2004a;230:13–18.
[PubMed]
19.
Keren I, Minami S, Rubin E, Lewis K: Characterization and transcriptome analysis of Mycobacterium tuberculosis persisters. MBio 2011;2:e00100–e00111.
20.
Keren I, Shah D, Spoering A, Kaldalu N, Lewis K: Specialized persister cells and the mechanism of multidrug tolerance in Escherichia coli. J Bacteriol 2004b;186:8172–8180.
[PubMed]
21.
Kussell E, Kishony R, Balaban NQ, Leibler S: Bacterial persistence: a model of survival in changing environments. Genetics 2005;169:1807–1814.
[PubMed]
22.
Kussell E, Leibler S: Phenotypic diversity, population growth, and information in fluctuating environments. Science 2005;309:2075–2078.
[PubMed]
23.
Lechner S, Lewis K, Bertram R: Staphylococcus aureus persisters tolerant to bactericidal antibiotics. J Mol Microbiol Biotechnol 2012;22:235–244.
[PubMed]
24.
Lewis K: Persister cells, dormancy and infectious disease. Nat Rev Microbiol 2007;5:48–56.
[PubMed]
25.
Lewis K: Persister cells. Annu Rev Microbiol 2010;64:357–372.
[PubMed]
26.
Maisonneuve E, Shakespeare LJ, Jørgensen MG, Gerdes K: Bacterial persistence by RNA endonucleases. Proc Natl Acad Sci USA 2011;108:13206–13211.
[PubMed]
27.
Massey RC, Buckling A, Peacock SJ: Phenotypic switching of antibiotic resistance circumvents permanent costs in Staphylococcus aureus. Curr Biol 2001;11:1810–1814.
[PubMed]
28.
Möker N, Dean CR, Tao J: Pseudomonas aeruginosa increases formation of multidrug-tolerant persister cells in response to quorum-sensing signaling molecules. J Bacteriol 2010;192:1946–1955.
[PubMed]
29.
Moyed HS, Bertrand KP: HipA, a newly recognized gene of Escherichia coli K-12 that affects frequency of persistence after inhibition of murein synthesis. J Bacteriol 1983;155:768–775.
[PubMed]
30.
Mukamolova GV, Kaprelyants AS, Young DI, Young M, Kell DB: A bacterial cytokine. Proc Natl Acad Sci USA 1998;95:8916–8921.
[PubMed]
31.
Proctor RA, von Eiff C, Kahl BC, Becker K, McNamara P, Herrmann M, Peters G: Small colony variants: a pathogenic form of bacteria that facilitates persistent and recurrent infections. Nat Rev Microbiol 2006;4:295–305.
[PubMed]
32.
Shah D, Zhang Z, Khodursky A, Kaldalu N, Kurg K, Lewis K: Persisters: a distinct physiological state of E. coli. BMC Microbiol 2006;6:53.
[PubMed]
33.
Shapiro JA, Nguyen VL, Chamberlain NR: Evidence for persisters in Staphylococcus epidermidis RP62A planktonic cultures and biofilms. J Med Microbiol 2011;60:950–960.
[PubMed]
34.
Singh R, Ray P, Das A, Sharma M: Role of persisters and small-colony variants in antibiotic resistance of planktonic and biofilm-associated Staphylococcus aureus: an in vitro study. J Med Microbiol 2009;58:1067–1073.
[PubMed]
35.
Tuchscherr L, Medina E, Hussain M, Völker W, Heitmann V, Niemann S, Holzinger D, Roth J, Proctor RA, Becker K, Peters G, Löffler B: Staphylococcus aureus phenotype switching: an effective bacterial strategy to escape host immune response and establish a chronic infection. EMBO Mol Med 2011;3:129–141.
[PubMed]
36.
Vazquez-Laslop N, Lee H, Neyfakh AA: Increased persistence in Escherichia coli caused by controlled expression of toxins or other unrelated proteins. J Bacteriol 2006;188:3494–3497.
[PubMed]
37.
von Eiff C: Staphylococcus aureus small colony variants: a challenge to microbiologists and clinicians. Int J Antimicrob Agents 2008;31:507–510.
[PubMed]
38.
Wiuff C, Zappala RM, Regoes RR, Garner KN, Baquero F, Levin BR: Phenotypic tolerance: antibiotic enrichment of noninherited resistance in bacterial populations. Antimicrob Agents Chemother 2005;49:1483–1494.
[PubMed]
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