D. Andersson and B. Levin, The biological cost of antibiotic resistance, Current Opinion in Microbiology, vol.2, issue.5, pp.489-493, 1999.
DOI : 10.1016/S1369-5274(99)00005-3

J. Björkman, I. Nagaev, O. Berg, D. Hughes, and D. Andersson, Effects of environment on compensatory mutations to ameliorate costs of antibiotic resistance, Science, vol.287, pp.1479-1482, 2000.

D. Andersson and D. Hughes, Antibiotic resistance and its cost: is it possible to reverse resistance?, Nature Reviews Microbiology, vol.179, pp.260-271, 2010.
DOI : 10.1038/nrmicro2319

P. Reynolds, Structure, biochemistry and mechanism of action of glycopeptide antibiotics, European Journal of Clinical Microbiology & Infectious Diseases, vol.157, issue.Supplement A, pp.943-950, 1989.
DOI : 10.1007/BF01967563

M. Arthur, F. Depardieu, P. Reynolds, and P. Courvalin, Quantitative analysis of the metabolism of soluble cytoplasmic peptidoglycan precursors of glycopeptide-resistant enterococci, Molecular Microbiology, vol.21, issue.1, pp.33-44, 1996.
DOI : 10.1046/j.1365-2958.1996.00617.x

F. Depardieu, I. Podglajen, R. Leclercq, E. Collatz, and P. Courvalin, Modes and Modulations of Antibiotic Resistance Gene Expression, Clinical Microbiology Reviews, vol.20, issue.1, pp.79-114, 2007.
DOI : 10.1128/CMR.00015-06

M. Arthur, F. Depardieu, L. Cabanié, P. Reynolds, and P. Courvalin, Requirement of the VanY and VanX D,D-peptidases for glycopeptide resistance in enterococci, Molecular Microbiology, vol.33, issue.4, pp.819-830, 1998.
DOI : 10.1046/j.1365-2958.1998.01114.x

F. Depardieu, P. Courvalin, and T. Msadek, A six amino acid deletion, partially overlapping the VanSB G2 ATP-binding motif, leads to constitutive glycopeptide resistance in VanB-type Enterococcus faecium, Molecular Microbiology, vol.45, issue.3, pp.1069-1083, 2003.
DOI : 10.1046/j.1365-2958.2003.03771.x

M. Arthur, C. Molinas, F. Depardieu, and P. Courvalin, Characterization of Tn1546, a Tn3-related transposon conferring glycopeptide resistance by synthesis of depsipeptide peptidoglycan precursors in Enterococcus faecium BM4147., Journal of Bacteriology, vol.175, issue.1, pp.117-127, 1993.
DOI : 10.1128/jb.175.1.117-127.1993

F. Garnier, S. Taourit, P. Glaser, P. Courvalin, and M. Galimand, Characterization of transposon Tn1549, conferring VanB-type resistance in Enterococcus spp., Microbiology, vol.146, issue.6, pp.1481-1489, 2000.
DOI : 10.1099/00221287-146-6-1481

P. Johnsen, G. Simonsen, O. Olsvik, T. Midtvedt, and A. Sundsfjord, and in Gnotobiotic Mice, Microbial Drug Resistance, vol.8, issue.3, pp.161-170, 2002.
DOI : 10.1089/107662902760326869

A. Ramadhan and E. Hegedus, Survivability of vancomycin resistant enterococci and fitness cost of vancomycin resistance acquisition, Journal of Clinical Pathology, vol.58, issue.7, pp.744-746, 2005.
DOI : 10.1136/jcp.2004.024091

A. Launay, S. Ballard, P. Johnson, M. Grayson, and T. Lambert, Transfer of Vancomycin Resistance Transposon Tn1549 from Clostridium symbiosum to Enterococcus spp. in the Gut of Gnotobiotic Mice, Antimicrobial Agents and Chemotherapy, vol.50, issue.3, pp.1054-1062, 2006.
DOI : 10.1128/AAC.50.3.1054-1062.2006

G. Werner, R. Willems, B. Hildebrandt, I. Klare, and W. Witte, Influence of Transferable Genetic Determinants on the Outcome of Typing Methods Commonly Used for Enterococcus faecium, Journal of Clinical Microbiology, vol.41, issue.4, pp.1499-1506, 2003.
DOI : 10.1128/JCM.41.4.1499-1506.2003

A. Jacob and S. Hobbs, Conjugal transfer of plasmid-borne multiple antibiotic resistance in Streptococcus faecalis var. zymogenes, J Bacteriol, vol.117, pp.360-372, 1974.

F. Van-bambeke, M. Chauvel, P. Reynolds, H. Fraimow, and P. Courvalin, Vancomycindependent Enterococcus faecalis clinical isolates and revertant mutants, Antimicrob Agents Chemother, vol.43, pp.41-47, 1999.

M. Foucault, L. Thomas, S. Goussard, B. Branchini, and C. Grillot-courvalin, In Vivo Bioluminescence Imaging for the Study of Intestinal Colonization by Escherichia coli in Mice, Applied and Environmental Microbiology, vol.76, issue.1, pp.264-274, 2010.
DOI : 10.1128/AEM.01686-09

C. Moubareck, N. Bourgeois, P. Courvalin, and F. Doucet-populaire, Multiple Antibiotic Resistance Gene Transfer from Animal to Human Enterococci in the Digestive Tract of Gnotobiotic Mice, Antimicrobial Agents and Chemotherapy, vol.47, issue.9, pp.2993-2996, 2003.
DOI : 10.1128/AAC.47.9.2993-2996.2003

Y. Cetinkaya, P. Falk, and C. Mayhall, Vancomycin-Resistant Enterococci, Clinical Microbiology Reviews, vol.13, issue.4, pp.686-707, 2000.
DOI : 10.1128/CMR.13.4.686-707.2000

L. Weigel, Genetic Analysis of a High-Level Vancomycin-Resistant Isolate of Staphylococcus aureus, Science, vol.302, issue.5650, pp.1569-1571, 2003.
DOI : 10.1126/science.1090956

V. Enne, Assessment of the fitness impacts on Escherichia coli of acquisition of antibiotic resistance genes encoded by different types of genetic element, Journal of Antimicrobial Chemotherapy, vol.56, issue.3, pp.544-551, 2005.
DOI : 10.1093/jac/dki255

S. Elena, L. Ekunwe, N. Hajela, S. Oden, and R. Lenski, Distribution of fitness effects caused by random insertion mutations in Escherichia coli, Genetica, vol.102103, pp.349-358, 1998.
DOI : 10.1007/978-94-011-5210-5_28

F. Depardieu, P. Courvalin, and A. Kolb, BM4524, Molecular Microbiology, vol.45, issue.2, pp.550-564, 2005.
DOI : 10.1111/j.1365-2958.2005.04706.x

D. Sievert, Vancomycin-Resistant Staphylococcus aureus in the United States, 2002-2006, Clinical Infectious Diseases, vol.46, issue.5, pp.668-674, 2002.
DOI : 10.1086/527392

M. Foucault, P. Courvalin, and C. Grillot-courvalin, Fitness Cost of VanA-Type Vancomycin Resistance in Methicillin-Resistant Staphylococcus aureus, Antimicrobial Agents and Chemotherapy, vol.53, issue.6, pp.2354-2359, 2009.
DOI : 10.1128/AAC.01702-08

D. Stoebel, A. Dean, and D. Dykhuizen, The Cost of Expression of Escherichia coli lac Operon Proteins Is in the Process, Not in the Products, Genetics, vol.178, issue.3, pp.1653-1660, 2008.
DOI : 10.1534/genetics.107.085399

J. Mainardi, R. Villet, T. Bugg, C. Mayer, and M. Arthur, Evolution of peptidoglycan biosynthesis under the selective pressure of antibiotics in Gram-positive bacteria, FEMS Microbiology Reviews, vol.32, issue.2, pp.386-408, 2008.
DOI : 10.1111/j.1574-6976.2007.00097.x

E. Maguin, H. Prévost, S. Ehrlich, and A. Gruss, Efficient insertional mutagenesis in lactococci and other gram-positive bacteria., Journal of Bacteriology, vol.178, issue.3, pp.931-935, 1996.
DOI : 10.1128/jb.178.3.931-935.1996

J. Björkman and D. Andersson, The cost of antibiotic resistance from a bacterial perspective, Drug Resistance Updates, vol.3, issue.4, pp.237-245, 2000.
DOI : 10.1054/drup.2000.0147

B. Branchini, Thermostable red and green light-producing firefly luciferase mutants for bioluminescent reporter applications, Analytical Biochemistry, vol.361, issue.2, pp.253-262, 2007.
DOI : 10.1016/j.ab.2006.10.043