A Clinically Selected Staphylococcus aureus clpP Mutant Survives Daptomycin Treatment by Reducing Binding of the Antibiotic and Adapting a Rod-Shaped Morphology.
[en] Daptomycin is a last-resort antibiotic used for the treatment of infections caused by Gram-positive antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). Treatment failure is commonly linked to accumulation of point mutations; however, the contribution of single mutations to resistance and the mechanisms underlying resistance remain incompletely understood. Here, we show that a single nucleotide polymorphism (SNP) selected during daptomycin therapy inactivates the highly conserved ClpP protease and is causing reduced susceptibility of MRSA to daptomycin, vancomycin, and β-lactam antibiotics as well as decreased expression of virulence factors. Super-resolution microscopy demonstrated that inactivation of ClpP reduced binding of daptomycin to the septal site and diminished membrane damage. In both the parental strain and the clpP strain, daptomycin inhibited the inward progression of septum synthesis, eventually leading to lysis and death of the parental strain while surviving clpP cells were able to continue synthesis of the peripheral cell wall in the presence of 10× MIC daptomycin, resulting in a rod-shaped morphology. To our knowledge, this is the first demonstration that synthesis of the outer cell wall continues in the presence of daptomycin. Collectively, our data provide novel insight into the mechanisms behind bacterial killing and resistance to this important antibiotic. Also, the study emphasizes that treatment with last-line antibiotics is selective for mutations that, like the SNP in clpP, favor antibiotic resistance over virulence gene expression.
Disciplines :
Microbiology
Author, co-author :
Xu, Lijuan; Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
Henriksen, Camilla; Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
Mebus, Viktor; Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
Guérillot, Romain; Department of Microbiology and Immunology, University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
Petersen, Andreas; Statens Serum Institute, Copenhagen, Denmark
Jacques, Nicolas ; Université de Liège - ULiège > GIGA > GIGA Cardiovascular Sciences - Cardiology
Jiang, Jhih-Hang; Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia ; Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia ; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
Derks, Rico J E; Leiden University Medical Center, Center for Proteomics and Metabolomics, Leiden, Netherlands
Sánchez-López, Elena; Leiden University Medical Center, Center for Proteomics and Metabolomics, Leiden, Netherlands
Giera, Martin; Leiden University Medical Center, Center for Proteomics and Metabolomics, Leiden, Netherlands
Stinear, Timothy P ; Department of Microbiology and Immunology, University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
Howden, Benjamin P; Department of Microbiology and Immunology, University of Melbourne at the Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
Peleg, Anton Y ; Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia ; Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia ; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
Frees, Dorte ; Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
A Clinically Selected Staphylococcus aureus clpP Mutant Survives Daptomycin Treatment by Reducing Binding of the Antibiotic and Adapting a Rod-Shaped Morphology.
Tong SYC, Davis JS, Eichenberger E, Holland TL, Fowler VG. 2015. Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management. Clin Microbiol Rev 28:603-661. https://doi.org/10.1128/CMR.00134-14.
Murray CJL, Ikuta KS, Sharara F, Swetschinski L, Robles Aguilar G, Gray A, Han C, Bisignano C, Rao P, Wool E, Johnson SC, Browne AJ, Chipeta MG, Fell F, Hackett S, Haines-Woodhouse G, Kashef Hamadani BH, Kumaran EAP, McManigal B, Achalapong S, Agarwal R, Akech S, Albertson S, Amuasi J, Andrews J, Aravkin A, Ashley E, Babin F-X, Bailey F, Baker S, Basnyat B, Bekker A, Bender R, Berkley JA, Bethou A, Bielicki J, Boonkasidecha S, Bukosia J, Carvalheiro C, Castañeda-Orjuela C, Chansamouth V, Chaurasia S, Chiurchiù S, Chowdhury F, Clotaire Donatien R, Cook AJ, Cooper B, Cressey TR, Criollo-Mora E, Cunningham M, et al. 2022. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet 399:629-655. https://doi.org/10.1016/S0140-6736(21)02724-0.
Vestergaard M, Frees D, Ingmer H. 2019. Antibiotic resistance and the MRSA problem. Microbiol Spectr 7:7.2.18. https://doi.org/10.1128/microbiolspec.GPP3-0057-2018.
Liu C, Bayer A, Cosgrove SE, Daum RS, Fridkin SK, Gorwitz RJ, Kaplan SL, Karchmer AW, Levine DP, Murray BE, Rybak MJ, Talan DA, Chambers HF. 2011. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children: executive summary. Clin Infect Dis 52: 285-292. https://doi.org/10.1093/cid/cir034.
Mwangi MM, Shang WW, Zhou Y, Sieradzki K, De Lencastre H, Richardson P, Bruce D, Rubin E, Myers E, Siggia ED, Tomasz A. 2007. Tracking the in vivo evolution of multidrug resistance in Staphylococcus aureus by whole-genome sequencing. Proc Natl Acad Sci U S A 104:9451-9456. https://doi.org/10.1073/pnas.0609839104.
Howden BP, McEvoy CRE, Allen DL, Chua K, Gao W, Harrison PF, Bell J, Coombs G, Bennett-Wood V, Porter JL, Robins-Browne R, Davies JK, Seemann T, Stinear TP. 2011. Evolution of multidrug resistance during Staphylococcus aureus infection involves mutation of the essential two component regulator WalKR. PLoS Pathog 7:e1002359. https://doi.org/10.1371/journal.ppat.1002359.
Gardete S, Kim C, Hartmann BM, Mwangi M, Roux CM, Dunman PM, Chambers HF, Tomasz A. 2012. Genetic pathway in acquisition and loss of vancomycin resistance in a methicillin resistant Staphylococcus aureus (MRSA) strain of clonal type USA300. PLoS Pathog 8:e1002505. https://doi.org/10.1371/journal.ppat.1002505.
Peleg AY, Miyakis S, Ward DV, Earl AM, Rubio A, Cameron DR, Pillai S, Moellering RC, Eliopoulos GM. 2012. Whole genome characterization of the mechanisms of daptomycin resistance in clinical and laboratory derived isolates of Staphylococcus aureus. PLoS One 7:e28316. https://doi.org/10.1371/journal.pone.0028316.
Passalacqua KD, Satola SW, Crispell EK, Read TD. 2012. A mutation in the PP2C phosphatase gene in a Staphylococcus aureus USA300 clinical isolate with reduced susceptibility to vancomycin and daptomycin. Antimicrob Agents Chemother 56:5212-5223. https://doi.org/10.1128/AAC.05770-11.
Thitiananpakorn K, Aiba Y, Tan XE, Watanabe S, Kiga K, Sato'o Y, Boonsiri T, Li FY, Sasahara T, Taki Y, Azam AH, Zhang Y, Cui L. 2020. Association of mprF mutations with cross-resistance to daptomycin and vancomycin in methicillin-resistant Staphylococcus aureus (MRSA). Sci Rep 10:16107. https://doi.org/10.1038/s41598-020-73108-x.
Gray DA, Wenzel M. 2020. More than a pore: a current perspective on the in vivo mode of action of the lipopeptide antibiotic daptomycin. Antibiotics (Basel) 9:17. https://doi.org/10.3390/antibiotics9010017.
Silverman JA, Perlmutter NG, Shapiro HM. 2003. Correlation of daptomycin bactericidal activity and membrane depolarization in Staphylococcus aureus. Antimicrob Agents Chemother 47:2538-2544. https://doi.org/10.1128/AAC.47.8.2538-2544.2003.
Straus SK, Hancock REW. 2006. Mode of action of the new antibiotic for Gram-positive pathogens daptomycin: comparison with cationic antimicrobial peptides and lipopeptides. Biochim Biophys Acta - Biomembr 1758:1215-1223. https://doi.org/10.1016/j.bbamem.2006.02.009.
Muthaiyan A, Silverman JA, Jayaswal RK, Wilkinson BJ. 2008. Transcriptional profiling reveals that daptomycin induces the Staphylococcus aureus cell wall stress stimulon and genes responsive to membrane depolarization. Antimicrob Agents Chemother 52:980-990. https://doi.org/10.1128/AAC.01121-07.
Pogliano J, Pogliano N, Silverman JA. 2012. Daptomycin-mediated reorganization of membrane architecture causes mislocalization of essential cell division proteins. J Bacteriol 194:4494-4504. https://doi.org/10.1128/JB.00011-12.
Müller A, Wenzel M, Strahl H, Grein F, Saaki TNV, Kohl B, Siersma T, Bandow JE, Sahl HG, Schneider T, Hamoen LW. 2016. Daptomycin inhibits cell envelope synthesis by interfering with fluid membrane microdomains. Proc Natl Acad Sci U S A 113:E7077-E7086. https://doi.org/10.1073/pnas.1611173113.
Grein F, Müller A, Scherer KM, Liu X, Ludwig KC, Klöckner A, Strach M, Sahl HG, Kubitscheck U, Schneider T. 2020. Ca21-daptomycin targets cell wall biosynthesis by forming a tripartite complex with undecaprenyl-coupled intermediates and membrane lipids. Nat Commun 11:1455. https://doi.org/10.1038/s41467-020-15257-1.
Bayer AS, Mishra NN, Sakoulas G, Nonejuie P, Nast CC, Pogliano J, Chen K-T, Ellison SN, Yeaman MR, Yang S-J. 2014. Heterogeneity of mprF sequences in methicillin-resistant Staphylococcus aureus clinical isolates: role in cross-resistance between daptomycin and host defense antimicrobial peptides. Antimicrob Agents Chemother 58:7462-7467. https://doi.org/10.1128/AAC.03422-14.
Bayer AS, Mishra NN, Chen L, Kreiswirth BN, Rubio A, Yang SJ. 2015. Frequency and distribution of single-nucleotide polymorphisms within mprF in methicillin-resistant Staphylococcus aureus clinical isolates and their role in cross-resistance to daptomycin and host defense antimicrobial peptides. Antimicrob Agents Chemother 59:4930-4937. https://doi.org/10.1128/AAC.00970-15.
Jiang JH, Bhuiyan MS, Shen HH, Cameron DR, Rupasinghe TWT, Wu CM, Le Brun AP, Kostoulias X, Domene C, Fulcher AJ, McConville MJ, Howden BP, Lieschke GJ, Peleg AY. 2019. Antibiotic resistance and host immune evasion in Staphylococcus aureus mediated by a metabolic adaptation. Proc Natl Acad Sci U S A 116:3722-3727. https://doi.org/10.1073/pnas.1812066116.
Friedman L, Alder JD, Silverman JA. 2006. Genetic changes that correlate with reduced susceptibility to daptomycin in Staphylococcus aureus. Antimicrob Agents Chemother 50:2137-2145. https://doi.org/10.1128/AAC.00039-06.
Camargo IL, Neoh HM, Cui L, Hiramatsu K. 2008. Serial daptomycin selection generates daptomycin-nonsusceptible Staphylococcus aureus strains with a heterogeneous vancomycin-intermediate phenotype. Antimicrob Agents Chemother 52:4289-4299. https://doi.org/10.1128/AAC.00417-08.
Cui L, Isii T, Fukuda M, Ochiai T, Neoh HM, Da Cunha Camargo ILB, Watanabe Y, Shoji M, Hishinuma T, Hiramatsu K. 2010. An RpoB mutation confers dual heteroresistance to daptomycin and vancomycin in Staphylococcus aureus. Antimicrob Agents Chemother 54:5222-5233. https://doi.org/10.1128/AAC.00437-10.
Rose WE, Rybak MJ, Tsuji BT, Kaatz GW, Sakoulas G. 2007. Correlation of vancomycin and daptomycin susceptibility in Staphylococcus aureus in reference to accessory gene regulator (agr) polymorphism and function. J Antimicrob Chemother 59:1190-1193. https://doi.org/10.1093/jac/dkm091.
Shajari G, Khorshidi A, Moosavi G. 2017. Vancomycin resistance in Staphylococcus aureus strains. Arch Razi Inst 90:107-110.
Yamakawa J, Aminaka M, Okuzumi K, Kobayashi H, Katayama Y, Kondo S, Nakamura A, Oguri T, Hori S, Cui L, Ito T, Jin J, Kurosawa H, Kaneko K, Hiramatsu K. 2012. Heterogeneously vancomycin-intermediate Staphylococcus aureus (hVISA) emerged before the clinical introduction of vancomycin in Japan: a retrospective study. J Infect Chemother 18:406-409. https://doi.org/10.1007/s10156-011-0330-2.
Illigmann A, Thoma Y, Pan S, Reinhardt L, Brötz-Oesterhelt H. 2021. Contribution of the Clp protease to bacterial survival and mitochondrial homoeostasis. Microb Physiol 31:260-279. https://doi.org/10.1159/000517718.
Olivares AO, Baker TA, Sauer RT. 2016. Mechanistic insights into bacterial AAA1 proteases and protein-remodelling machines. Nat Rev Microbiol 14:33-44. https://doi.org/10.1038/nrmicro.2015.4.
Frees D, Qazi SNA, Hill PJ, Ingmer H. 2003. Alternative roles of ClpX and ClpP in Staphylococcus aureus stress tolerance and virulence. Mol Microbiol 48:1565-1578. https://doi.org/10.1046/j.1365-2958.2003.03524.x.
Farrand AJ, Reniere ML, Ingmer H, Frees D, Skaar EP. 2013. Regulation of host hemoglobin binding by the Staphylococcus aureus Clp proteolytic system. J Bacteriol 195:5041-5050. https://doi.org/10.1128/JB.00505-13.
Jacquet R, LaBauve AE, Akoolo L, Patel S, Alqarzaee AA, Wong Fok Lung T, Poorey K, Stinear TP, Thomas VC, Meagher RJ, Parker D. 2019. Dual gene expression analysis identifies factors associated with Staphylococcus aureus virulence in diabetic mice. Infect Immun 87:e00163-19. https://doi.org/10.1128/IAI.00163-19.
Kim GL, Akoolo L, Parker D. 2020. The ClpXP protease contributes to Staphylococcus aureus pneumonia. J Infect Dis 222:1400-1404. https://doi.org/10.1093/infdis/jiaa251.
Howden BP, Peleg AY, Stinear TP. 2014. The evolution of vancomycin intermediate Staphylococcus aureus (VISA) and heterogenous-VISA. Infect Genet Evol 21:575-582. https://doi.org/10.1016/j.meegid.2013.03.047.
McGuinness WA, Malachowa N, DeLeo FR. 2017. Vancomycin resistance in Staphylococcus aureus. Yale J Biol Med 90:269-281.
Shoji M, Cui L, Iizuka R, Komoto A, Neoh HM, Watanabe Y, Hishinuma T, Hiramatsu K. 2011. walK and clpP mutations confer reduced vancomycin susceptibility in Staphylococcus aureus. Antimicrob Agents Chemother 55:3870-3881. https://doi.org/10.1128/AAC.01563-10.
Bæk KT, Thøgersen L, Mogenssen RG, Mellergaard M, Thomsen LE, Petersen A, Skov S, Cameron DR, Peleg AY, Frees D. 2015. Stepwise decrease in daptomycin susceptibility in clinical Staphylococcus aureus isolates associated with an initial mutation in rpoB and a compensatory inactivation of the clpX gene. Antimicrob Agents Chemother 59:6983-6991. https://doi.org/10.1128/AAC.01303-15.
Mellergaard M, Høgh RI, Lund A, Aldana BI, Guérillot R, Møller SH, Hayes AS, Panagiotopoulou N, Frimand Z, Jepsen SD, Hansen CHF, Andresen L, Larsen AR, Peleg AY, Stinear TP, Howden BP, Waagepetersen HS, Frees D, Skov S. 2020. Staphylococcus aureus induces cell-surface expression of immune stimulatory NKG2D ligands on human monocytes. J Biol Chem 295:11803-11821. https://doi.org/10.1074/jbc.RA120.012673.
Frees D, Andersen JH, Hemmingsen L, Koskenniemi K, Bæk KT, Muhammed MK, Gudeta DD, Nyman TA, Sukura A, Varmanen P, Savijoki K. 2012. New insights into Staphylococcus aureus stress tolerance and virulence regulation from an analysis of the role of the ClpP protease in the strains Newman, COL, and SA564. J Proteome Res 11:95-108. https://doi.org/10.1021/pr200956s.
Bæk KT, Gründling A, Mogensen RG, Thøgersen L, Petersen A, Paulander W, Frees D. 2014. b-lactam resistance in methicillin-resistant Staphylococcus aureus USA300 is increased by inactivation of the ClpXP protease. Antimicrob Agents Chemother 58:4593-4603. https://doi.org/10.1128/AAC.02802-14.
Stahlhut SG, Alqarzaee AA, Jensen C, Fisker NS, Pereira AR, Pinho MG, Thomas VC, Frees D. 2017. The ClpXP protease is dispensable for degradation of unfolded proteins in Staphylococcus aureus. Sci Rep 7:11739. https://doi.org/10.1038/s41598-017-12122-y.
Schelin J, Cohn MT, Frisk B, Frees D. 2020. A functional ClpXP protease is required for induction of the accessory toxin genes, tst, sed, and sec. Toxins (Basel) 12:553. https://doi.org/10.3390/toxins12090553.
Feng J, Michalik S, Varming AN, Andersen JH, Albrecht D, Jelsbak L, Krieger S, Ohlsen K, Hecker M, Gerth U, Ingmer H, Frees D. 2013. Trapping and proteomic identification of cellular substrates of the ClpP protease in Staphylococcus aureus. J Proteome Res 12:547-558. https://doi.org/10.1021/pr300394r.
Thalsø-Madsen I, Torrubia FR, Xu L, Petersen A, Jensen C, Frees D. 2019. The Sle1 cell wall amidase is essential for b-Lactam resistance in community-acquired methicillin-resistant Staphylococcus aureus USA300. Antimicrob Agents Chemother 64:e01931-19. https://doi.org/10.1128/AAC.01931-19.
O'Neill AJ, Huovinen T, Fishwick CWG, Chopra I. 2006. Molecular genetic and structural modeling studies of Staphylococcus aureus RNA polymerase and the fitness of rifampin resistance genotypes in relation to clinical prevalence. Antimicrob Agents Chemother 50:298-309. https://doi.org/10.1128/AAC.50.1.298-309.2006.
Guérillot R, Gonçalves da Silva A, Monk I, Giulieri S, Tomita T, Alison E, Porter J, Pidot S, Gao W, Peleg AY, Seemann T, Stinear TP, Howden BP. 2018. Convergent evolution driven by rifampin exacerbates the global burden of drug-resistant Staphylococcus aureus. mSphere 3:e00550-17. https://doi.org/10.1128/mSphere.00550-17.
Ledger EVK, Mesnage S, Edwards AM. 2022. Human serum triggers antibiotic tolerance in Staphylococcus aureus. Nat Commun 13:2041. https://doi.org/10.1038/s41467-022-29717-3.
Reichmann NT, Tavares AC, Saraiva BM, Jousselin A, Reed P, Pereira AR, Monteiro JM, Sobral RG, VanNieuwenhze MS, Fernandes F, Pinho MG. 2019. SEDS-bPBP pairs direct lateral and septal peptidoglycan synthesis in Staphylococcus aureus. Nat Microbiol 4:1368-1377. https://doi.org/10.1038/s41564-019-0437-2.
Kuru E, Hughes HV, Brown PJ, Hall E, Tekkam S, Cava F, de Pedro MA, Brun YV, VanNieuwenhze MS. 2012. In situ probing of newly synthesized peptidoglycan in live bacteria with fluorescent D-amino acids. Angew Chem Int Ed Engl 51:12519-12523. https://doi.org/10.1002/anie.201206749.
Jensen C, Bæk KT, Gallay C, Thalsø-Madsen I, Xu L, Jousselin A, Torrubia FR, Paulander W, Pereira AR, Veening JW, Pinho MG, Frees D. 2019. The ClpX chaperone controls autolytic splitting of Staphylococcus aureus daughter cells, but is bypassed by b-lactam antibiotics or inhibitors of WTA biosynthesis. PLoS Pathog 15:e1008044. https://doi.org/10.1371/journal.ppat.1008044.
Bojer MS, Wacnik K, Kjelgaard P, Gallay C, Bottomley AL, Cohn MT, Lindahl G, Frees D, Veening JW, Foster SJ, Ingmer H. 2019. SosA inhibits cell division in Staphylococcus aureus in response to DNA damage. Mol Microbiol 112:1116-1130. https://doi.org/10.1111/mmi.14350.
Monteiro JM, Fernandes PB, Vaz F, Pereira AR, Tavares AC, Ferreira MT, Pereira PM, Veiga H, Kuru E, VanNieuwenhze MS, Brun YV, Filipe SR, Pinho MG. 2015. Cell shape dynamics during the staphylococcal cell cycle. Nat Commun 6:8055. https://doi.org/10.1038/ncomms9055.
Lund VA, Wacnik K, Turner RD, Cotterell BE, Walther CG, Fenn SJ, Grein F, Wollman AJ, Leake MC, Olivier N, Cadby A, Mesnage S, Jones S, Foster SJ. 2018. Molecular coordination of Staphylococcus aureus cell division. Elife 7:e32057. https://doi.org/10.7554/eLife.32057.
Biswas R, Voggu L, Simon UK, Hentschel P, Thumm G, Götz F. 2006. Activity of the major staphylococcal autolysin Atl. FEMS Microbiol Lett 259: 260-268. https://doi.org/10.1111/j.1574-6968.2006.00281.x.
Kajimura J, Fujiwara T, Yamada S, Suzawa Y, Nishida T, Oyamada Y, Hayashi I, Yamagishi J, Komatsuzawa H, Sugai M. 2005. Identification and molecular characterization of an N-acetylmuramyl-L-alanine amidase Sle1 involved in cell separation of Staphylococcus aureus. Mol Microbiol 58: 1087-1101. https://doi.org/10.1111/j.1365-2958.2005.04881.x.
Nega M, Tribelli PM, Hipp K, Stahl M, Götz F. 2020. New insights in the coordinated amidase and glucosaminidase activity of the major autolysin (Atl) in Staphylococcus aureus. Commun Biol 3:695. https://doi.org/10.1038/s42003-020-01405-2.
Fowler VG, Jr, Boucher HW, Corey GR, Abrutyn E, Karchmer AW, Rupp ME, Levine DP, Chambers HF, Tally FP, Vigliani GA, Cabell CH, Link AS, DeMeyer I, Filler SG, Zervos M, Cook P, Parsonnet J, Bernstein JM, Price CS, Forrest GN, Fätkenheuer G, Gareca M, Rehm SJ, Brodt HR, Tice A, Cosgrove SE. S. aureus Endocarditis and Bacteremia Study Group. 2006. Daptomycin versus standard therapy for bacteremia and endocarditis caused by Staphylococcus aureus. N Engl J Med 355:653-665. https://doi.org/10.1056/NEJMoa053783.
Laabei M, Uhlemann AC, Lowy FD, Austin ED, Yokoyama M, Ouadi K, Feil E, Thorpe HA, Williams B, Perkins M, Peacock SJ, Clarke SR, Dordel J, Holden M, Votintseva AA, Bowden R, Crook DW, Young BC, Wilson DJ, Recker M, Massey RC. 2015. Evolutionary trade-offs underlie the multi-faceted virulence of Staphylococcus aureus. PLoS Biol 13:e1002229. https://doi.org/10.1371/journal.pbio.1002229.
Tuchscherr L, Pöllath C, Siegmund A, Deinhardt-Emmer S, Hoerr V, Svensson CM, Thilo Figge M, Monecke S, Löffler B. 2019. Clinical S. aureus isolates vary in their virulence to promote adaptation to the host. Toxins (Basel) 11:135. https://doi.org/10.3390/toxins11030135.
Cameron DR, Mortin LI, Rubio A, Mylonakis E, Moellering RC, Jr, Eliopoulos GM, Peleg AY. 2015. Impact of daptomycin resistance on Staphylococcus aureus virulence. Virulence 6:127-131. https://doi.org/10.1080/21505594.2015.1011532.
de Mesy Bentley KL, MacDonald A, Schwarz EM, Oh I. 2018. Chronic osteomyelitis with Staphylococcus aureus deformation in submicron canaliculi of osteocytes: a case report. JBJS Case Connect 8:e8. https://doi.org/10.2106/JBJS.CC.17.00154.
Müller A, Grein F, Otto A, Gries K, Orlov D, Zarubaev V, Girard M, Sher X, Shamova O, Roemer T, François P, Becher D, Schneider T, Sahl HG. 2018. Differential daptomycin resistance development in Staphylococcus aureus strains with active and mutated gra regulatory systems. Int J Med Microbiol 308:335-348. https://doi.org/10.1016/j.ijmm.2017.12.002.
Engman J, Rogstam A, Frees D, Ingmer H, Von Wachenfeldt C. 2012. The YjbH adaptor protein enhances proteolysis of the transcriptional regulator Spx in Staphylococcus aureus. J Bacteriol 194:1186-1194. https://doi.org/10.1128/JB.06414-11.
Pamp SJ, Frees D, Engelmann S, Hecker M, Ingmer H. 2006. Spx is a global effector impacting stress tolerance and biofilm formation in Staphylococcus aureus. J Bacteriol 188:4861-4870. https://doi.org/10.1128/JB.00194-06.
Villanueva M, Jousselin A, Baek KT, Prados J, Andrey DO, Renzoni A, Ingmer H, Frees D, Kelley WL. 2016. Rifampin resistance rpoB alleles or multicopy thioredoxin/thioredoxin reductase suppresses the lethality of disruption of the global stress regulator spx in Staphylococcus aureus. J Bacteriol 198:2719-2731. https://doi.org/10.1128/JB.00261-16.
Runde S, Molière N, Heinz A, Maisonneuve E, Janczikowski A, Elsholz AKW, Gerth U, Hecker M, Turgay K. 2014. The role of thiol oxidative stress response in heat-induced protein aggregate formation during thermotolerance in Bacillus subtilis. Mol Microbiol 91:1036-1052. https://doi.org/10.1111/mmi.12521.
Rojas-Tapias DF, Helmann JD. 2018. Stabilization of Bacillus subtilis Spx under cell wall stress requires the anti-adaptor protein YirB. PLoS Genet 14:e1007531. https://doi.org/10.1371/journal.pgen.1007531.
Sugai M, Akiyama T, Komatsuzawa H, Miyake Y, Suginaka H. 1990. Characterization of sodium dodecyl sulfate-stable Staphylococcus aureus bacteriolytic enzymes by polyacrylamide gel electrophoresis. J Bacteriol 172: 6494-6498. https://doi.org/10.1128/jb.172.11.6494-6498.1990.