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Genome-Wide Identification of Ampicillin Resistance Determinants in


Enterococcus faecium has become a nosocomial pathogen of major importance, causing infections that are difficult to treat owing to its multi-drug resistance. In particular, resistance to the β-lactam antibiotic ampicillin has become ubiquitous among clinical isolates. Mutations in the low-affinity penicillin binding protein PBP5 have previously been shown to be important for ampicillin resistance in E. faecium, but the existence of additional resistance determinants has been suggested. Here, we constructed a high-density transposon mutant library in E. faecium and developed a transposon mutant tracking approach termed Microarray-based Transposon Mapping (M-TraM), leading to the identification of a compendium of E. faecium genes that contribute to ampicillin resistance. These genes are part of the core genome of E. faecium, indicating a high potential for E. faecium to evolve towards β-lactam resistance. To validate the M-TraM results, we adapted a Cre-lox recombination system to construct targeted, markerless mutants in E. faecium. We confirmed the role of four genes in ampicillin resistance by the generation of targeted mutants and further characterized these mutants regarding their resistance to lysozyme. The results revealed that ddcP, a gene predicted to encode a low-molecular-weight penicillin binding protein with D-alanyl-D-alanine carboxypeptidase activity, was essential for high-level ampicillin resistance. Furthermore, deletion of ddcP sensitized E. faecium to lysozyme and abolished membrane-associated D,D-carboxypeptidase activity. This study has led to the development of a broadly applicable platform for functional genomic-based studies in E. faecium, and it provides a new perspective on the genetic basis of ampicillin resistance in this organism.


Vyšlo v časopise: Genome-Wide Identification of Ampicillin Resistance Determinants in. PLoS Genet 8(6): e32767. doi:10.1371/journal.pgen.1002804
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pgen.1002804

Souhrn

Enterococcus faecium has become a nosocomial pathogen of major importance, causing infections that are difficult to treat owing to its multi-drug resistance. In particular, resistance to the β-lactam antibiotic ampicillin has become ubiquitous among clinical isolates. Mutations in the low-affinity penicillin binding protein PBP5 have previously been shown to be important for ampicillin resistance in E. faecium, but the existence of additional resistance determinants has been suggested. Here, we constructed a high-density transposon mutant library in E. faecium and developed a transposon mutant tracking approach termed Microarray-based Transposon Mapping (M-TraM), leading to the identification of a compendium of E. faecium genes that contribute to ampicillin resistance. These genes are part of the core genome of E. faecium, indicating a high potential for E. faecium to evolve towards β-lactam resistance. To validate the M-TraM results, we adapted a Cre-lox recombination system to construct targeted, markerless mutants in E. faecium. We confirmed the role of four genes in ampicillin resistance by the generation of targeted mutants and further characterized these mutants regarding their resistance to lysozyme. The results revealed that ddcP, a gene predicted to encode a low-molecular-weight penicillin binding protein with D-alanyl-D-alanine carboxypeptidase activity, was essential for high-level ampicillin resistance. Furthermore, deletion of ddcP sensitized E. faecium to lysozyme and abolished membrane-associated D,D-carboxypeptidase activity. This study has led to the development of a broadly applicable platform for functional genomic-based studies in E. faecium, and it provides a new perspective on the genetic basis of ampicillin resistance in this organism.


Zdroje

1. HidronAIEdwardsJRPatelJHoranTCSievertDM 2008 NHSN annual update: antimicrobial-resistant pathogens associated with healthcare-associated infections: annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006–2007. Infect Control Hosp Epidemiol 29 996 1011

2. WillemsRJvan SchaikW 2009 Transition of Enterococcus faecium from commensal organism to nosocomial pathogen. Future Microbiol 4 1125 1135

3. AmmerlaanHSTroelstraAKruitwagenCLKluytmansJABontenMJ 2009 Quantifying changes in incidences of nosocomial bacteraemia caused by antibiotic-susceptible and antibiotic-resistant pathogens. J Antimicrob Chemother 63 1064 1070

4. TopJWillemsRBlokHde RegtMJalinkK 2007 Ecological replacement of Enterococcus faecalis by multiresistant clonal complex 17 Enterococcus faecium. Clin Microbiol Infect 13 316 319

5. LeavisHLBontenMJWillemsRJ 2006 Identification of high-risk enterococcal clonal complexes: global dispersion and antibiotic resistance. Curr Opin Microbiol 9 454 460

6. van SchaikWWillemsRJ 2010 Genome-based insights into the evolution of enterococci. Clin Microbiol Infect 16 527 532

7. AriasCAContrerasGAMurrayBE 2010 Management of multidrug-resistant enterococcal infections. Clin Microbiol Infect 16 555 562

8. MurdochDRMirrettSHarrellLJMonahanJSRellerLB 2002 Sequential emergence of antibiotic resistance in enterococcal bloodstream isolates over 25 years. Antimicrob Agents Chemother 46 3676 3678

9. GraysonMLEliopoulosGMWennerstenCBRuoffKLDe GirolamiPC 1991 Increasing resistance to beta-lactam antibiotics among clinical isolates of Enterococcus faecium: a 22-year review at one institution. Antimicrob Agents Chemother 35 2180 2184

10. MurrayBE 2000 Vancomycin-resistant enterococcal infections. N Engl J Med 342 710 721

11. WernerGCoqueTMHammerumAMHopeRHryniewiczW 2008 Emergence and spread of vancomycin resistance among enterococci in Europe. Euro Surveill 13: pii 19046

12. MonteroCIStockFMurrayPR 2008 Mechanisms of resistance to daptomycin in Enterococcus faecium. Antimicrob Agents Chemother 52 1167 1170

13. ScheetzMHKnechtelSAMalczynskiMPostelnickMJQiC 2008 Increasing incidence of linezolid-intermediate or -resistant, vancomycin-resistant Enterococcus faecium strains parallels increasing linezolid consumption. Antimicrob Agents Chemother 52 2256 2259

14. AriasCAPanessoDMcGrathDMQinXMojicaMF 2011 Genetic basis for in vivo daptomycin resistance in enterococci. N Engl J Med 365 892 900

15. MurrayBE 1990 The life and times of the Enterococcus. Clin Microbiol Rev 3 46 65

16. FontanaRGrossatoARossiLChengYRSattaG 1985 Transition from resistance to hypersusceptibility to beta-lactam antibiotics associated with loss of a low-affinity penicillin-binding protein in a Streptococcus faecium mutant highly resistant to penicillin. Antimicrob Agents Chemother 28 678 683

17. WilliamsonRle BouguenecCGutmannLHoraudT 1985 One or two low affinity penicillin-binding proteins may be responsible for the range of susceptibility of Enterococcus faecium to benzylpenicillin. J Gen Microbiol 131 1933 1940

18. FontanaRAldegheriMLigozziMLopezHSucariA 1994 Overproduction of a low-affinity penicillin-binding protein and high-level ampicillin resistance in Enterococcus faecium. Antimicrob Agents Chemother 38 1980 1983

19. Galloway-PenaJRRiceLBMurrayBE 2011 Analysis of PBP5 of Early U.S. Isolates of Enterococcus faecium: Sequence Variation Alone Does Not Explain Increasing Ampicillin Resistance over Time. Antimicrob Agents Chemother 55 3272 3277

20. RiceLBBellaisSCariasLLHutton-ThomasRBonomoRA 2004 Impact of specific pbp5 mutations on expression of beta-lactam resistance in Enterococcus faecium. Antimicrob Agents Chemother 48 3028 3032

21. MainardiJLLegrandRArthurMSchootBvan HeijenoortJ 2000 Novel mechanism of beta-lactam resistance due to bypass of DD-transpeptidation in Enterococcus faecium. J Biol Chem 275 16490 16496

22. MainardiJLMorelVFourgeaudMCremniterJBlanotD 2002 Balance between two transpeptidation mechanisms determines the expression of beta-lactam resistance in Enterococcus faecium. J Biol Chem 277 35801 35807

23. SaccoEHugonnetJEJosseaumeNCremniterJDubostL 2010 Activation of the L,D-transpeptidation peptidoglycan cross-linking pathway by a metallo-D,D-carboxypeptidase in Enterococcus faecium. Mol Microbiol 75 874 885

24. van SchaikWTopJRileyDRBoekhorstJVrijenhoekJE 2010 Pyrosequencing-based comparative genome analysis of the nosocomial pathogen Enterococcus faecium and identification of a large transferable pathogenicity island. BMC Genomics 11 239

25. WalshCT 1989 Enzymes in the D-alanine branch of bacterial cell wall peptidoglycan assembly. J Biol Chem 264 2393 2396

26. HeikensEBontenMJWillemsRJ 2007 Enterococcal surface protein Esp is important for biofilm formation of Enterococcus faecium E1162. J Bacteriol 189 8233 8240

27. HeikensESinghKVJacques-PalazKDvan Luit-AsbroekMOostdijkEA 2011 Contribution of the enterococcal surface protein Esp to pathogenesis of Enterococcus faecium endocarditis. Microbes Infect 13 1185 1190

28. LeendertseMHeikensEWijnandsLMvan Luit-AsbroekMTeskeGJ 2009 Enterococcal surface protein transiently aggravates Enterococcus faecium-induced urinary tract infection in mice. J Infect Dis 200 1162 1165

29. LamMMSeemannTBulachDMGladmanSLChenH 2012 Comparative Analysis of the First Complete Enterococcus faecium Genome. J Bacteriol 194 2334 2341

30. SauvageEKerffFTerrakMAyalaJACharlierP 2008 The penicillin-binding proteins: structure and role in peptidoglycan biosynthesis. FEMS Microbiol Rev 32 234 258

31. LeiXHFiedlerFLanZKathariouS 2001 A novel serotype-specific gene cassette (gltA-gltB) is required for expression of teichoic acid-associated surface antigens in Listeria monocytogenes of serotype 4b. J Bacteriol 183 1133 1139

32. HorsburghGJAtrihAWilliamsonMPFosterSJ 2003 LytG of Bacillus subtilis is a novel peptidoglycan hydrolase: the major active glucosaminidase. Biochemistry 42 257 264

33. MagnetSArbeloaAMainardiJLHugonnetJEFourgeaudM 2007 Specificity of L,D-transpeptidases from gram-positive bacteria producing different peptidoglycan chemotypes. J Biol Chem 282 13151 13159

34. ZhangXVrijenhoekJEBontenMJWillemsRJVan SchaikW 2011 A genetic element present on megaplasmids allows Enterococcus faecium to use raffinose as carbon source. Environ Microbiol 13 518 528

35. CallewaertLMichielsCW 2010 Lysozymes in the animal kingdom. J Biosci 35 127 160

36. KangYDurfeeTGlasnerJDQiuYFrischD 2004 Systematic mutagenesis of the Escherichia coli genome. J Bacteriol 186 4921 4930

37. ChristenBAbeliukECollierJMKalogerakiVSPassarelliB 2011 The essential genome of a bacterium. Mol Syst Biol 7 528

38. Galloway-PenaJRNallapareddySRAriasCAEliopoulosGMMurrayBE 2009 Analysis of clonality and antibiotic resistance among early clinical isolates of Enterococcus faecium in the United States. J Infect Dis 200 1566 1573

39. SauerB 1987 Functional expression of the cre-lox site-specific recombination system in the yeast Saccharomyces cerevisiae. Mol Cell Biol 7 2087 2096

40. GhoshASChowdhuryCNelsonDE 2008 Physiological functions of D-alanine carboxypeptidases in Escherichia coli. Trends Microbiol 16 309 317

41. SarkarSKChowdhuryCGhoshAS 2010 Deletion of penicillin-binding protein 5 (PBP5) sensitises Escherichia coli cells to beta-lactam agents. Int J Antimicrob Agents 35 244 249

42. MemmiGFilipeSRPinhoMGFuZCheungA 2008 Staphylococcus aureus PBP4 is essential for beta-lactam resistance in community-acquired methicillin-resistant strains. Antimicrob Agents Chemother 52 3955 3966

43. CampbellJSinghAKSanta MariaJPJrKimYBrownS 2011 Synthetic lethal compound combinations reveal a fundamental connection between wall teichoic acid and peptidoglycan biosyntheses in Staphylococcus aureus. ACS Chem Biol 6 106 116

44. LeavisHLWillemsRJvan WamelWJSchurenFHCaspersMP 2007 Insertion sequence-driven diversification creates a globally dispersed emerging multiresistant subspecies of E. faecium. PLoS Pathog 3 e7 doi:10.1371/journal.ppat.0030007

45. BushLMCalmonJCherneyCLWendelerMPitsakisP 1989 High-level penicillin resistance among isolates of enterococci. Implications for treatment of enterococcal infections. Ann Intern Med 110 515 520

46. LeenhoutsKBuistGBolhuisAten BergeAKielJ 1996 A general system for generating unlabelled gene replacements in bacterial chromosomes. Mol Gen Genet 253 217 224

47. KristichCJNguyenVTLeTBarnesAMGrindleS 2008 Development and use of an efficient system for random mariner transposon mutagenesis to identify novel genetic determinants of biofilm formation in the core Enterococcus faecalis genome. Appl Environ Microbiol 74 3377 3386

48. NallapareddySRSinghKVMurrayBE 2006 Construction of improved temperature-sensitive and mobilizable vectors and their use for constructing mutations in the adhesin-encoding acm gene of poorly transformable clinical Enterococcus faecium strains. Appl Environ Microbiol 72 334 345

49. AkerleyBJLampeDJ 2002 Analysis of gene function in bacterial pathogens by GAMBIT. Methods Enzymol 358 100 108

50. LampeDJAkerleyBJRubinEJMekalanosJJRobertsonHM 1999 Hyperactive transposase mutants of the Himar1 mariner transposon. Proc Natl Acad Sci U S A 96 11428 11433

51. ArthurMDepardieuFSnaithHAReynoldsPECourvalinP 1994 Contribution of VanY D,D-carboxypeptidase to glycopeptide resistance in Enterococcus faecalis by hydrolysis of peptidoglycan precursors. Antimicrob Agents Chemother 38 1899 1903

52. WilsonACPeregoMHochJA 2007 New transposon delivery plasmids for insertional mutagenesis in Bacillus anthracis. J Microbiol Methods 71 332 335

53. ChaudhuriRRAllenAGOwenPJShalomGStoneK 2009 Comprehensive identification of essential Staphylococcus aureus genes using Transposon-Mediated Differential Hybridisation (TMDH). BMC Genomics 10 291

54. BijlsmaJJBurghoutPKloostermanTGBootsmaHJde JongA 2007 Development of genomic array footprinting for identification of conditionally essential genes in Streptococcus pneumoniae. Appl Environ Microbiol 73 1514 1524

55. BaldiPLongAD 2001 A Bayesian framework for the analysis of microarray expression data: regularized t -test and statistical inferences of gene changes. Bioinformatics 17 509 519

56. LeibigMKrismerBKolbMFriedeAGotzF 2008 Marker removal in staphylococci via Cre recombinase and different lox sites. Appl Environ Microbiol 74 1316 1323

57. BryanEMBaeTKleerebezemMDunnyGM 2000 Improved vectors for nisin-controlled expression in gram-positive bacteria. Plasmid 44 183 190

58. AndrewsJM 2001 Determination of minimum inhibitory concentrations. J Antimicrob Chemother 48 Suppl 1 5 16

59. LebretonFDepardieuFBourdonNFines-GuyonMBergerP 2011 D-Ala-D-Ser VanN-Type Transferable Vancomycin Resistance in Enterococcus faecium. Antimicrob Agents Chemother 55 4606 4612

60. ArthurMDepardieuFReynoldsPCourvalinP 1996 Quantitative analysis of the metabolism of soluble cytoplasmic peptidoglycan precursors of glycopeptide-resistant enterococci. Mol Microbiol 21 33 44

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