1887

Abstract

Since their first description in 1988, glycopeptide-resistant enterococci (GRE) have emerged as a significant cause of nosocomial infections and colonisations, particularly in Europe and the USA. Two major genetically distinct forms of acquired resistance, designated VanA and VanB, are recognised, although intrinsic resistance occurs in some enterococcal species (VanC) and a third form of acquired resistance (VanD) has been reported recently. The biochemical basis of each resistance mechanism is similar; the resistant enterococci produce modified peptidoglycan precursors that show decreased binding affinity for glycopeptide antibiotics. Although VanA resistance is detected readily in the clinical laboratory, the variable levels of vancomycin resistance associated with the other phenotypes makes detection less reliable. Under-reporting of VanB resistance as a result of a lower detection rate may account, in part, for the difference in the numbers of enterococci displaying VanA and VanB resistance referred to the PHLS Laboratory of Hospital Infection. Since 1987, GRE have been referred from >1100 patients in almost 100 hospitals, but 88% of these isolates displayed the VanA phenotype. It is possible that, in addition to the problems of detection, there may be a real difference in the prevalence of VanA and VanB resistance reflecting different epidemiologies. Our present understanding of the genetic and biochemical basis of these acquired forms of glycopeptide resistance has been gained mainly in the last 5 years. However, these relatively new enterococcal resistances appear still to be evolving; there have now been reports of transferable VanB resistance associated with either large chromosomally borne transposons or plasmids, genetic linkage of glycopeptide resistance and genes conferring high-level resistance to aminoglycoside antibiotics, epidemic strains of glycopeptide-resistant isolated from multiple patients in numerous hospitals, and of glycopeptide dependence (mutant enterococci that actually require these agents for growth). The gene clusters responsible for VanA and VanB resistance are located on transposable elements, and both transposition and plasmid transfer have resulted in the dissemination of these resistance genes into diverse strains of several species of enterococci. Despite extensive research, knowledge of the origins of these resistances remains poor. There is little homology between the resistance genes and DNA from either intrinsically resistant gram-positive genera or from the soil bacteria that produce glycopeptides, which argues against direct transfer to enterococci from these sources. However, recent data suggest a more distant, evolutionary relationship with genes found in glycopeptide-producing bacteria. In Europe, VanA resistance occurs in enterococci isolated in the community, from sewage, animal faeces and raw meat. This reservoir suggests that VanA may not have evolved in hospitals, and its existence has been attributed, controversially, to use of the glycopeptide avoparcin as a growth promoter, especially in pigs and poultry. However, as avoparcin has never been licensed for use in the USA and, to date, VanB resistance has not been confirmed in non-human enterococci, it is clear that the epidemiology of acquired glycopeptide resistance in enterococci is complex, with many factors contributing to its evolution and global dissemination.

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References

  1. Uttley A. H. C., Collins C. H., Naidoo J., George R. C. Vancomycin-resistant enterococci. Lancet 1988; 1:57–58
    [Google Scholar]
  2. Leclercq R., Derlot E., Duval J., Courvalin P. Strains of Enterococcus faecium highly resistant to vancomycin and teicoplanin. Program and Abstracts of the 27th Interscience Conference on Antimicrobial Agents and Chemotherapy; 1987; 275: Abstract 1023
    [Google Scholar]
  3. Leclercq R., Derlot E., Duval J., Courvalin P. Plasmid-mediated resistance to vancomycin and teicoplanin in Enterococcus faecium. N Engl J Med 1988; 319:157–161
    [Google Scholar]
  4. Perichon B., Reynolds P., Courvalin P. VanD-type glycopeptide-resistant Enterococcus faecium BM4339. Antimicrob Agents Chemother 1997; 41:2016–2018
    [Google Scholar]
  5. Clark N. C., Hill B. C., Tenover F. C. Characterization of an Enterococcus raffinosus isolate with a VanB phenotype and vanA genotype. Program and Abstracts of the 94th ASM General Meeting 1994 A-111
    [Google Scholar]
  6. Hayden M. K., Picken R. N., Sahm D. F. Heterogeneous expression of glycopeptide resistance in enterococci associated with transfer of vanB. Antimicrob Agents Chemother 1997; 41:872–874
    [Google Scholar]
  7. Hayden M. K., Trenholme G. M., Schultz J. E., Sahm D. F. In vivo development of teicoplanin resistance in a VanB Enterococcus faecium isolate. J Infect Dis 1993; 167:1224–1227
    [Google Scholar]
  8. Green M., Binczewski B., Pasculle A. W. Constitutively vancomycin-resistant Enterococcus faecium resistant to synergistic ß-lactam combinations. Antimicrob Agents Chemother 1993; 37:1238–1242
    [Google Scholar]
  9. Sahm D. F., Free L., Handwerger S. Inducible and constitutive expression of vanC-1-encoded resistance to vancomycin in Enterococcus gallinarum. Antimicrob Agents Chemother 1995; 39:1480–1484
    [Google Scholar]
  10. Arthur M., Molinas C., Depardieu F., Courvalin P. Characterization of Tn1546, a Tn3-related transposon conferring glycopeptide resistance by synthesis of depsipeptide peptidoglycan precursors in Enterococcus faecium BM4147. J Bacteriol 1993; 175:117–127
    [Google Scholar]
  11. Quintiliani R., Courvalin P. Characterization of Tn1547, a composite transposon flanked by IS16 and IS256-like elements, that confers vancomycin resistance in Enterococcus faecalis BM4281. Gene 1996; 172:1–8
    [Google Scholar]
  12. Morrison D., Woodford N., Cookson B. Enterococci as emerging pathogens of humans. J Appl Microbiol 1997; 83: (Suppl) 89S–99S
    [Google Scholar]
  13. Brisson-Noel A., Dutka-Malen S., Molinas C., Leclercq R., Courvalin P. Cloning and heterospecific expression of the resistance determinant vanA encoding high-level resistance to glycopeptides in Enterococcus faecium BM4147. Antimicrob Agents Chemother 1990; 34:924–927
    [Google Scholar]
  14. Noble W. C., Virani Z., Cree R. G. A. Co-transfer of vancomycin and other resistance genes from Enterococcus faecalis NCTC 12201 to Staphylococcus aureus. FEMS Microbiol Lett 1992; 93:195–198
    [Google Scholar]
  15. Fontana R., Ligozzi M., Pedrotti C., Padovani E. M., Comaglia G. Vancomycin-resistant Bacillus circulans carrying the vanA gene responsible for vancomycin resistance in enterococci. Eur J Clin Microbiol Infect Dis 1997; 16:473–474
    [Google Scholar]
  16. Power E. G. M., Abdulla Y. H., Talsania H. G., Spice W., Aathithan S., French G. L. vanA genes in vancomycin-resistant clinical isolates of Oeskovia turbata and Arcanobacterium (Coryne-bacterium) haemolyticum. J Antimicrob Chemother 1995; 36:595–606
    [Google Scholar]
  17. Goldstein F. W., Buu-Hoi A. Y., Williamson R., Acar J. F. A vancomycin-resistant Enterococcus faecium susceptible to teichomycin. Program and Abstracts of the 27th Interscience Conference on Antimicrobial Agents and Chemotherapy 1987; 275: Abstract 1022
    [Google Scholar]
  18. Williamson R., Al-Obeid S., Shlaes J. H., Goldstein F. W., Shlaes D. M. Inducible resistance to vancomycin in Enterococcus faecium D366. J Infect Dis 1989; 159:1095–1104
    [Google Scholar]
  19. Woodford N., Johnson A. P., Morrison D., Chin A. T. L., Stephenson J. R., George R. C. Two distinct forms of vancomycin resistance amongst enterococci in the UK. Lancet 1990; 335:226
    [Google Scholar]
  20. Quintiliani R., Evers S., Courvalin P. The vanB gene confers various levels of self-transferable resistance to vancomycin in enterococci. J Infect Dis 1993; 167:1220–1223
    [Google Scholar]
  21. Poyart C., Pierre C., Quesne G., Pron B., Berche P., Trieu-Cuot P. Emergence of vancomycin resistance in the genus Streptococcus: characterization of a vanB transferable determinant in Streptococcus bovis. Antimicrob Agents Chemother 1997; 41:24–29
    [Google Scholar]
  22. Vincent S., Minkler P., Bincziewski B., Etter L., Shlaes D. M. Vancomycin resistance in Enterococcus gallinarum. Antimicrob Agents Chemother 1992; 36:1392–1399
    [Google Scholar]
  23. Snell J. J. S., Brown D. F. J., Perry S. F., George R. Antimicrobial susceptibility testing of enterococci: results of a survey conducted by the United Kingdom National External Quality Assessment Scheme for Microbiology. J Antimicrob Chemother 1993; 32:401–411
    [Google Scholar]
  24. Tenover F. C., Tokars J., Swenson J., Paul S., Spitalny K., Jarvis W. Ability of clinical laboratories to detect antimicrobial agent-resistant enterococci. J Clin Microbiol 1993; 31:1695–1699
    [Google Scholar]
  25. Jett B., Free L., Sahm D. F. Factors influencing the Vitek grampositive susceptibility system’s detection of vanB-encoded vancomycin resistance among enterococci. J Clin Microbiol 1996; 34:701–706
    [Google Scholar]
  26. Rosenberg J., Tenover F. C., Wong J., Jarvis W., Vugia D. J. Are clinical laboratories in California accurately reporting vancomycin-resistant enterococci?. J Clin Microbiol 1997; 35:2526–2530
    [Google Scholar]
  27. Woodford N., Johnson A. P., Morrison D., Speller D. C. E. Current perspectives on glycopeptide resistance. Clin Microbiol Rev 1995; 8:585–615
    [Google Scholar]
  28. National Committee for Clinical Laboratory Standards Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. 3rd edn. Approved Standard M7-A3 Villanova P. A.: National Committee for Clinical Laboratory Standards; 1993
    [Google Scholar]
  29. Woodford N., Jones B. L., Baccus Z., Ludlam H. A., Brown D. F. J. Linkage of vancomycin and high-level gentamicin resistance genes on the same plasmid in a clinical isolate of Enterococcus faecalis. J Antimicrob Chemother 1995; 35:179–184
    [Google Scholar]
  30. Woodford N., Morrison D., Johnson A. P. Plasmid-mediated vanB glycopeptide resistance in enterococci. Microb Drug Resist 1995; 1:235–240
    [Google Scholar]
  31. Woodford N., Morrison D., Johnson A. P., Briant V., George R. C., Cookson B. Application of DNA probes for rRNA and vanA genes to investigation of a nosocomial cluster of vancomycin-resistant enterococci. J Clin Microbiol 1993; 31:653–658
    [Google Scholar]
  32. Dutka-Malen S., Evers S., Courvalin P. Detection of glycopeptide resistance genotypes and identification to the species level of clinically relevant enterococci by PCR. J Clin Microbiol 1995; 33:24–27
    [Google Scholar]
  33. Dutka-Malen S., Evers S., Courvalin P. Detection of glycopeptide resistance genotypes and identification to the species level of clinically relevant enterococci by PCR (Erratum). J Clin Microbiol 1995; 33:1434
    [Google Scholar]
  34. Woodford N., Egelton C. M., Morrison D. Comparison of PCR with phenotypic methods for the speciation of enterococci. In Horaud T., Bouvet A., Leclercq R., de Montclos H., Sicard M. (eds) Streptococci and the host (Advances in experimental medicine and biology, vol 418.) New York: Plenum Publishing Corporation; 1997405–408
    [Google Scholar]
  35. Allen N. E., Hobbs J. N., Richardson J. M., Riggin R. M. Biosynthesis of modified peptidoglycan precursors by vancomycin-resistant Enterococcus faecium. FEMS Microbiol Lett 1992; 98:109–115
    [Google Scholar]
  36. Arthur M., Molinas C., Bugg T. D. H., Wright G. D., Walsh C. T., Courvalin P. Evidence for in vivo incorporation of D-lactate into peptidoglycan precursors of vancomycin-resistant enterococci. Antimicrob Agents Chemother 1992; 36:867–869
    [Google Scholar]
  37. Handwerger S., Pucci M. J., Volk K. J., Liu J., Lee M. S. The cytoplasmic peptidoglycan precursor of vancomycin-resistant Enterococcus faecalis terminates in lactate. J Bacteriol 1992; 174:5982–5984
    [Google Scholar]
  38. Billot-Klein D., Shlaes D., Bryant D., Bell D., van Heijenoort J., Gutmann L. Peptidoglycan structure of Enterococcus faecium expressing vancomycin resistance of the VanB type. Biochem J 1996; 313:711–715
    [Google Scholar]
  39. Reynolds P. E., Snaith H. A., Maguire A. J., Dutka-Malen S., Courvalin P. Analysis of peptidoglycan precursors in vancomycin-resistant Enterococcus gallinarum BM4174. Biochem J 1994; 301:5–8
    [Google Scholar]
  40. Bugg T. D. H., Dutka-Malen S., Arthur M., Courvalin P., Walsh C. T. Identification of vancomycin resistance protein VanA as a d-alanine: d-alanine ligase of altered substrate specificity. Biochemistry 1991; 30:2017–2021
    [Google Scholar]
  41. Evers S., Reynolds P. E., Courvalin P. Sequence of the vanB and ddl genes encoding D-alanine: D-lactate and D-alanine: D-alanine ligases in vancomycin-resistant Enterococcus faecalis V583. Gene 1994; 140:97–102
    [Google Scholar]
  42. Evers S., Sahm D. F., Courvalin P. The vanB gene of vancomycin-resistant Enterococcus faecalis V583 is structurally related to genes encoding D-Ala: D-Ala ligases and glycopeptide-resistance proteins VanA and VanC. Gene 1993; 124:143–144
    [Google Scholar]
  43. Dutka-Malen S., Molinas C., Arthur M., Courvalin P. Sequence of the vanC gene of Enterococcus gallinarum BM4174 encoding a D-alanine:D-alanine ligase-related protein necessary for vancomycin resistance. Gene 1992; 112:53–58
    [Google Scholar]
  44. Navarro F., Courvalin P. Analysis of genes encoding D-alanine: D-alanine ligase-related enzymes in Enterococcus casseliflavus and Enterococcus flavescens. Antimicrob Agents Chemother 1994; 38:1788–1793
    [Google Scholar]
  45. Uttley A. H. C., George R. C., Naidoo J. High-level vancomycin-resistant enterococci causing hospital infection. Epidemiol Infect 1989; 103:173–181
    [Google Scholar]
  46. Handwerger S., Skoble J. Identification of chromosomal mobile element conferring high-level vancomycin resistance in Enterococcus faecium. Antimicrob Agents Chemother 1995; 39:2446–2453
    [Google Scholar]
  47. Quintiliani R., Courvalin P. Conjugal transfer of the vancomycin resistance determinant vanB between enterococci involves the movement of large genetic elements from chromosome to chromosome. FEMS Microbiol Lett 1994; 119:359–364
    [Google Scholar]
  48. Arthur M., Molinas C., Dutka-Malen S., Courvalin P. Structural relationship between the vancomycin resistance protein VanH and 2-hydroxycarboxylic acid dehydrogenases. Gene 1991; 103:133–134
    [Google Scholar]
  49. Bugg T. D. H., Wright G. D., Dutka-Malen S., Arthur M., Courvalin P., Walsh C. T. Molecular basis for vancomycin resistance in Enterococcus faecium BM4147: biosynthesis of a depsipeptide peptidoglycan precursor by vancomycin resistance proteins VanH and VanA. Biochemistry 1991; 30:10408–10415
    [Google Scholar]
  50. Evers S., Courvalin P. Regulation of VanB-type vancomycin resistance gene expression by the VanSB-VanRB two-component regulatory system in Enterococcus faecalis V583. J Bacteriol 1996; 178:1302–1309
    [Google Scholar]
  51. Reynolds P. E., Depardieu F., Dutka-Malen S., Arthur M., Courvalin P. Glycopeptide resistance mediated by enterococcal transposon Tn1546 requires production of VanX for hydrolysis of D-alanyl-D-alanine. Mol Microbiol 1994; 13:1065–1070
    [Google Scholar]
  52. Wright G. D., Molinas C., Arthur M., Courvalin P., Walsh C. T. Characterization of VanY, a DD-carboxypeptidase from vancomycin-resistant Enterococcus faecium BM4147. Antimicrob Agents Chemother 1992; 36:1514–1518
    [Google Scholar]
  53. Arthur M., Depardieu F., Snaith H. A., Reynolds P. E., Courvalin P. Contribution of VanY D,D-carboxypeptidase to glycopeptide resistance in Enterococcus faecalis by hydrolysis of peptidoglycan precursors. Antimicrob Agents Chemother 1994; 38:1899–1903
    [Google Scholar]
  54. Arthur M., Depardieu F., Molinas C., Reynolds P., Courvalin P. The vanZ gene of Tn1546 from Enterococcus faecium BM4147 confers resistance to teicoplanin. Gene 1995; 154:87–92
    [Google Scholar]
  55. Nicas T. I., Wu C. Y. E., Hobbs J. N., Preston D. A., Allen N. E. Characterization of vancomycin resistance in Enterococcus faecium and Enterococcus faecalis. Antimicrob Agents Che-mother 1989; 33:1121–1124
    [Google Scholar]
  56. Shlaes D. M., Bouvet A., Devine C., Shlaes J. H., al-Obeid S., Williamson R. Inducible, transferable resistance to vancomycin in Enterococcus faecalis A256. Antimicrob Agents Chemother 1989; 33:198–203
    [Google Scholar]
  57. Arthur M., Molinas C., Courvalin P. The VanS-VanR two-component regulatory system controls synthesis of depsipeptide peptidoglycan precursors in Enterococcus faecium BM4147. J Bacteriol 1992; 174:2582–2591
    [Google Scholar]
  58. Holman T. R., Wu Z., Wanner B. L., Walsh C. T. Identification of the DNA-binding site for the phosphorylated VanR protein required for vancomycin resistance in Enterococcus faecium. Biochemistry 1994; 33:4625–4631
    [Google Scholar]
  59. Arthur M., Depardieu F., Gerbaud G., Galimand M., Leclercq R., Courvalin P. The VanS sensor negatively controls VanR-mediated transcriptional activation of glycopeptide resistance genes in Tn1546 and related elements in the absence of induction. J Bacteriol 1997; 179:97–106
    [Google Scholar]
  60. Handwerger S., Discotto L., Thanassi J., Pucci M. J. Insertional inactivation of a gene which controls expression of vancomycin resistance on plasmid pHKK100. FEMS Microbiol Lett 1992; 92:11–14
    [Google Scholar]
  61. Baptista M., Depardieu F., Reynolds P., Courvalin P., Arthur M. Mutations leading to increased levels of resistance to glycopeptide antibiotics in VanB-type enterococci. Mol Microbiol 1997; 25:93–105
    [Google Scholar]
  62. Fraimow H. S., Jungkind D. L., Lander D. W., Delso D. R., Dean J. L. Urinary tract infection with an Enterococcus faecalis isolate that requires vancomycin for growth. Ann Intern Med 1994; 121:22–26
    [Google Scholar]
  63. Woodford N., Johnson A. P., Morrison D. Vancomycin-dependent enterococci in the United Kingdom. J Antimicrob Chemother 1994; 33:1066
    [Google Scholar]
  64. Green M., Shlaes J. H., Barbadora K., Shlaes D. M. Bacteremia due to vancomycin-dependent Enterococcus faecium. Clin Infect Dis 1995; 20:712–714
    [Google Scholar]
  65. Slifkin M., Weinbaum D., Cumbie R. Vancomycin-dependent Enterococcus faecium from a blood culture. Med Microbiol Lett 1995; 4:406–413
    [Google Scholar]
  66. Wilks M., Farrag N., Eltringham I. J., Hayek L., Rossney A. S., McConkey S. J., Keane C. T. Vancomycin-dependent enterococcus. Lancet 1997; 349:429–430 (four letters)
    [Google Scholar]
  67. Stewart B., Hall L., Duke B., Ball D. Vancomycin-dependent enterococci: curious phenomenon or serious threat?. J Antimicrob Chemother 1997; 40:734–735
    [Google Scholar]
  68. Rosato A., Pierre J., Billot-Klein D., Buu-Hoi A., Gutmann L. Inducible and constitutive expression of resistance to glycopeptides and vancomycin dependence in glycopeptide-resistant Enterococcus avium. Antimicrob Agents Chemother 1995; 39:830–833
    [Google Scholar]
  69. Aslangul E., Baptista M., Fantin B. Selection of glycopeptide-resistant mutants of Van-B-type Enterococcus faecalis BM4281 in vitro and in experimental endocarditis. J Infect Dis 1997; 175:598–605
    [Google Scholar]
  70. Sifaoui F., Gutmann L. Vancomycin dependence in a VanA-producing Enterococcus avium strain with a nonsense mutation in the natural d-Ala-d-Ala ligase gene. Antimicrob Agents Chemother 1997; 41:1409
    [Google Scholar]
  71. Farrag N., Eltringham I., Liddy H. Vancomycin-dependent Enterococcus faecalis. Lancet 1996; 348:1581–1582
    [Google Scholar]
  72. Jett B. D., Huycke M. M., Gilmore M. S. Virulence in enterococci. Clin Microbiol Rev 1994; 7:462–478
    [Google Scholar]
  73. Johnson A. P. The pathogenicity of enterococci. J Antimicrob Chemother 1994; 33:1083–1089
    [Google Scholar]
  74. Morrison D., Woodford N., Cookson B. D. Epidemic vancomycin-resistant Enterococcus faecium in the UK. Clin Microbiol Infect 1996; 1:146–147
    [Google Scholar]
  75. Morrison D., Cooke R. P. D., Kaufmann M. E., Cookson B. D., Stephenson J. Inter-hospital spread of vancomycin-resistant Enterococcus faecium. J Hosp Infect 1997; 36:77–78
    [Google Scholar]
  76. Chadwick P. R., Oppenheim B. A., Fox A., Woodford N., Morgenstern G. R., Scarffe J. H. Epidemiology of an outbreak due to glycopeptide-resistant Enterococcus faecium on a leukaemia unit. J Hosp Infect 1996; 34:171–182
    [Google Scholar]
  77. Johnson A. P., Uttley A. H. C., Woodford N., George R. C. Resistance to vancomycin and teicoplanin: an emerging clinical problem. Clin Microbiol Rev 1990; 3:280–291
    [Google Scholar]
  78. McDonald L. C., Jarvis W. R. The global impact of vancomycin-resistant enterococci. Curr Opin Infect Dis 1997; 10:304–309
    [Google Scholar]
  79. Chow J. W., Kuritza A., Shlaes D. M., Green M., Sahm D. F., Zervos M. J. Clonal spread of vancomycin-resistant Enterococcus faecium between patients in three hospitals in two states. J Clin Microbiol 1993; 31:1609–1611
    [Google Scholar]
  80. Dunne W. M., Wang W. Clonal dissemination and colony morphotype variation of vancomycin-resistant Enterococcus faecium isolates in Metropolitan Detroit, Michigan. J Clin Microbiol 1997; 35:388–392
    [Google Scholar]
  81. Bates J., Jordens Z., Selkon J. B. Evidence for an animal origin of vancomycin-resistant enterococci. Lancet 1993; 342:490–491
    [Google Scholar]
  82. Bates J., Jordens J. Z., Griffiths D. T. Farm animals as a putative reservoir for vancomycin-resistant enterococcal infection in man. J Antimicrob Chemother 1994; 34:507–514
    [Google Scholar]
  83. Torres C., Reguera J. A., Sanmartin M. J., Perez-Diaz J. C., Baquero F. vanA-Mediated vancomycin-resistant Enterococcus spp. in sewage. J Antimicrob Chemother 1994; 33:553–561
    [Google Scholar]
  84. Aarestrup F. M. Occurrence of glycopeptide resistance among Enterococcus faecium isolates from conventional and ecological poultry farms. Microb Drug Resist 1995; 1:255–257
    [Google Scholar]
  85. Klare I., Heier H., Claus H. Enterococcus faecium strains with vanA-mediated high-level glycopeptide resistance isolated from animal foodstuffs and fecal samples of humans in the community. Microb Drug Resist 1995; 1:265–272
    [Google Scholar]
  86. Klare I., Heier H., Claus H., Reissbrodt R., Witte W. vanA- mediated high-level glycopeptide resistance in Enterococcus faecium from animal husbandry. FEMS Microbiol Lett 1995; 125:165–172
    [Google Scholar]
  87. Witte W., Klare I. Glycopeptide-resistant Enterococcus faecium outside hospitals: a commentary. Microb Drug Resist 1995; 1:259–263
    [Google Scholar]
  88. Aarestrup F. M., Ahrens P., Madsen M., Pallesen L. Y., Poulsen R. L., Westh H. Glycopeptide susceptibility among Danish Enterococcus faecium and Enterococcus faecalis isolates of animal and human origin and PCR identification of genes within the VanA cluster. Antimicrob Agents Chemother 1996; 40:1938–1940
    [Google Scholar]
  89. Chadwick P. R., Woodford N., Kaczmarski E. B., Gray S., Barrell R. A., Oppenheim B. A. Glycopeptide-resistant enterococci from uncooked meat. J Antimicrob Chemother 1996; 38:908–909
    [Google Scholar]
  90. Devriese L. A., Ieven M., Goossens H. Presence of vancomycin-resistant enterococci in farm and pet animals. Antimicrob Agents Chemother 1996; 40:2285–2287
    [Google Scholar]
  91. Van der Auwera P., Pensart N., Korten V., Murray B. E., Leclercq R. Influence of oral glycopeptides on the fecal flora of human volunteers: selection of highly glycopeptide-resistant enterococci. J Infect Dis 1996; 173:1129–1136
    [Google Scholar]
  92. Wegener H. C., Madsen M., Nielsen N., Aarestrup F. M. Isolation of vancomycin resistant Enterococcus faecium from food. Int J Food Microbiol 1997; 35:57–66
    [Google Scholar]
  93. Coque T. M., Tomayko J. F., Ricke S. C., Okhyusen P. C., Murray B. E. Vancomycin-resistant enterococci from nosocomial, community, and animal sources in the United States. Antimicrob Agents Chemother 1996; 40:2605–2609
    [Google Scholar]
  94. Dunne W. M. J., Dunne B. S., Smith D. Watch out where the huskies go. ASM News 1996; 62:283
    [Google Scholar]
  95. Schouten M. A., Voss A., Hoogkamp-Korstanje J. A. A. VRE and meat. Lancet 1997; 349:1258
    [Google Scholar]
  96. van Belkum A., van den Braak N., Thomassen R., Verbrugh H., Endtz H. Vancomycin-resistant enterococci in cats and dogs. Lancet 1996; 348:1038–1039
    [Google Scholar]
  97. Wise R. Avoparcin and animal feedstuff. Lancet 1996; 347:1835
    [Google Scholar]
  98. Mudd A. Vancomycin resistance and avoparcin. Lancet 1996; 347:1412
    [Google Scholar]
  99. Bager F., Madsen M., Christensen J., Aarestrup F. M. Avoparcin used as a growth promoter is associated with the occurrence of vancomycin-resistant Enterococcus faecium on Danish poultry and pig farms. Prev Vet Med 1997; 31:95–112
    [Google Scholar]
  100. McDonald L. C., Kuehnert M. J., Tenover F. C., Jarvis W. R. Vancomycin-resistant enterococci outside the health-care setting: prevalence, sources, and public health implications. Emerg Infect Dis 1997; 3:311–317
    [Google Scholar]
  101. Van den Bogaard A. E., Jensen L. B., Stobberingh E. E. Vancomycin-resistant enterococci in turkeys and farmers. N Engl J Med 1997; 337:1558–1559
    [Google Scholar]
  102. Miele A., Bandera M., Goldstein B. P. Use of primers selective for vancomycin resistance genes to determine van genotype in enterococci and to study gene organization in VanA isolates. Antimicrob Agents Chemother 1995; 39:1772–1778
    [Google Scholar]
  103. Jensen L. B., Ahrens P., Dons L., Jonesm R. N., Hammerum A. M., Aarestrup F. M. Molecular analysis of Tn1546 in Enterococcus faecium isolated from animals and humans. J Clin Microbiol 1998 (in press)
    [Google Scholar]
  104. Woodford N., Adebiyi A. A., Palepou M. I., Cookson B. D. Diversity of VanA glycopeptide resistance elements in enterococci from human and non-human sources. Antimicrob Agents Chemother 1998; 42:502–508
    [Google Scholar]
  105. Handwerger S., Skoble J., Discotto L. F., Pucci M. J. Heterogeneity of the vanA gene cluster in clinical isolates of enterococci from the Northeastern United States. Antimicrob Agents Chemother 1995; 39:362–368
    [Google Scholar]
  106. Mackinnon M. G., Drebot M. A., Tyrell G. J. Identification and characterization of IS1476, an insertion sequence-like element that disrupts VanY function in a vancomycin-resistant Enterococcus faecium strain. Antimicrob Agents Chemother 1997; 41:1805–1807
    [Google Scholar]
  107. Woodford N., Watson A. P., Chadwick P. R. Investigation by long PCR of the genetic elements mediating VanA glycopeptide resistance in enterococci from uncooked meat in South Manchester. In Horaud T., Bouvet A., Leclercq R., de Montclos H., Sicar M. (eds) Streptococci and the host Plenum, (Advances in experimental medicine and biology, vol 418.) New York: 1997409–412
    [Google Scholar]
  108. Woodford N., Stigter J. M. Molecular investigation of glycopeptide resistance in gram-positive bacteria. In Woodford N., Johnson A. P. (eds) Molecular bacteriology: protocols and clinical applications Humana Press; Totowa, NJ: 1998579–615
    [Google Scholar]
  109. Dutka-Malen S., Molinas C., Arthur M., Courvalin P. The VANA glycopeptide resistance protein is related to D-alanyl-D-alanine ligase cell wall biosynthesis enzymes. Mol Gen Genet 1990; 224:364–372
    [Google Scholar]
  110. Dutka-Malen S., Leclercq R., Coutant V., Duval J., Courvalin P. Phenotypic and genotypic heterogeneity of glycopeptide resistance determinants in gram-positive bacteria. Antimicrob Agents Chemother 1990; 34:1875–1879
    [Google Scholar]
  111. Sosio M., Lorenzetti R., Robbiati F., Denaro M. Nucleotide sequence to a teicoplanin resistance gene from Actinoplanes teichomyceticus. Biochem Biophys Acta 1991; 1089:401–403
    [Google Scholar]
  112. Billot-Klein D., Gutmann L., Sable S., Guittet E., van Heijenoort J. Modification of peptidoglycan precursors is a common feature of the low-level vancomycin-resistant VANB-type Enterococcus faecium D366 and of the naturally glycopeptide-resistant species Lactobacillus casei, Pediococcus pento-saceus, Leuconostoc mesenteroides, and Enterococcus gallinarum. J Bacteriol 1994; 176:2398–2405
    [Google Scholar]
  113. Elisha B. G., Courvalin P. Analysis of genes encoding D-alanine: D-alanine ligase-related enzymes in Leuconostoc mesenteroides and Lactobacillus spp. Gene 1995; 152:79–83
    [Google Scholar]
  114. Handwerger S., Pucci M. J., Volk K. J., Liu J., Lee M. S. Vancomycin-resistant Leuconostoc mesenteroides and Lactobacillus casei synthesize cytoplasmic peptidoglycan precursors that terminate in lactate. J Bacteriol 1994; 176:260–264
    [Google Scholar]
  115. Evers S., Casadewall B., Charles M., Dutka-Malen S., Galimand M. Courvalin P. Evolution of structure and substrate specificity in D-alanine: D-alanine ligases and related enzymes. J Mol Evol 1996; 42:706–712
    [Google Scholar]
  116. Marshall C. G., Broadhead G., Leskiw B. K., Wright G. D. d-Ala-d-ala ligases from glycopeptide antibiotic-producing organisms are highly homologous to the enterococcal vancomycin-resistance ligases VanA and VanB. Proc Natl Acad Sci USA 1997; 94:6480–6483
    [Google Scholar]
  117. Moellering R. C. The enterococcus: a classic example of the impact of antimicrobial resistance on therapeutic options. J Antimicrob Chemother 1991; 28:1–12
    [Google Scholar]
  118. Murray B. E. The life and times of the Enterococcus. Clin Microbiol Rev 1990; 3:46–65
    [Google Scholar]
  119. Michel M., Gutmann L. Methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci: therapeutic realities and possibilities. Lancet 1997; 349:1901–1906
    [Google Scholar]
  120. Fantin B., Leclercq R., Arthur M., Duval J., Carbon C. Influence of low-level resistance to vancomycin on efficacy of teicoplanin and vancomycin for treatment of experimental endocarditis due to Enterococcus faecium. Antimicrob Agents Chemother 1991; 35:1570–1575
    [Google Scholar]
  121. Nicas T. I., Zeckel M. L., Braun D. K. Beyond vancomycin: new therapies to meet the challenge of glycopeptide resistance. Trends Microbiol 1997; 5:240–249
    [Google Scholar]
  122. Woodford N., Palepou M.-F., Johnson A. P., Chadwick P. R., Bates J. Methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. Lancet 1997; 350:738
    [Google Scholar]
  123. Hiramatsu K., Hanaki H., Ino T., Yabuta K., Oguri T., Tenover F. C. Methicillin-resistant Staphylococcus aureus clinical strain with reduced vancomycin susceptibility. J Antimicrob Chemother 1997; 40:135–136
    [Google Scholar]
  124. Martin R., Wilcox K. R. Staphylococcus aureus with reduced susceptibility to vancomycin - United States, 1997. MMWR 1997; 46:765–766
    [Google Scholar]
  125. Anonymous Detecting vancomycin intermediate Staphylococcus aureus. CDR Weekly 1997; 7:417–420
    [Google Scholar]
  126. Boyle-Vavra S., de Jonge B. L. M., Ebert C. C., Daum R. S. Cloning of the Staphylococcus aureus ddh gene encoding NAD+-dependent D-lactate dehydrogenase and insertional inactivation in a glycopeptide-resistant isolate. J Bacteriol 1997; 179:6756–6763
    [Google Scholar]
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