Original report| Volume 6, ISSUE 4, P302-308, December 2002

Emergence of vancomycin resistance during therapy against methicillin-resistant Staphylococcus aureus in a burn patient—importance of low-level resistance to vancomycin

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      Objectives: Staphylococcus aureus with low-level resistance to vancomycin (VLSA) which could develop into vancomycin-resistant S. aureus (VRSA) is most important. However, VLSA is difficult to detect by standard laboratory methods. We describe here improved methods to detect VLSA.
      Methods: Three methicillin-resistant S. aureus (MRSA) strains, designated Fu6, Fu10, and Fu18, were sequentially isolated from the burn wound site of a patient, during vancomycin therapy. The properties of these strains were compared with those of reference strains Mu3 and Mu50 (previous resistant isolates from other patients).
      Results: The isolated strains, Fu10 and Fu18, had identical phenotypes and genotypes. The vancomycin resistance of Fu10 was equivalent to that of strain Mu3, whereas Fu18 had much higher vancomycin resistance than Fu10 and Mu3, although reaching the level of Mu50. Fu18 showed similar growth to Mu50 on gradient gels and on Mu3 medium.
      Conclusions: Our data indicate that the VLSA developed vancomycin resistance during exposure to vancomycin in vivo. The population analysis of tested VLSA and vancomycin intermediately resistant S. aureus (VISA) indicates that a penem at relatively low concentrations induced a significant increase in the number of vancomycin-resistant subpopulations. Furthermore, we confirmed that gradient gel analysis and Mu3 medium are simple and useful methods for the detection of VLSA judged as VSSA by its conventional MIC alone.


        • Hiramatsu K.
        • Aritaka N.
        • Hanaki H.
        • et al.
        Dissemination in Japanese hospitals of strains of Staphylococcus aureus heterogeneously resistant to vancomycin.
        Lancet. 1997; 350: 1670-1673
        • Ayliffe G.A.J.
        The progressive intercontinental spread of methicillin-resistant Staphylococcus aureus.
        Clin Infect Dis. 1997; 24: S74-S79
        • Tabaqchali S.
        Vancomycin-resistant Staphylococcus aureus: apocalypse now?.
        Lancet. 1997; 350: 1644-1645
        • Hiramatsu K.
        • Hanaki H.
        • Ito 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
      1. Staphylococcus aureus with reduced susceptibility to vancomycin-United States, 1997.
        MMWR. 1997; 46: 765-766
      2. Erratum.
        MMWR. 1997; 46: 851
      3. Update: Staphylococcus aureus with reduced susceptibility to vancomycin-United States, 1997.
        MMWR. 1997; 46: 813-815
      4. Erratum.
        MMWR. 1997; 46: 851
        • Ploy M.C.
        • Grelaud C.
        • Martin C.
        • de Lumley L.
        • Denis E.
        First clinical isolate of vancomycin-intermediate Staphylococcus aureus in a French hospital.
        Lancet. 1998; 351: 1212
        • Turco T.F.
        • Melko G.P.
        • Williams J.R.
        Vancomycin intermediate-resistant Staphylococcus aureus.
        Ann Pharmacother. 1998; 32: 758-760
        • Smith T.L.
        • Pearson M.L.
        • Wilcox K.R.
        • et al.
        Emergence of vancomycin resistance in Staphylococcus aureus.
        N Engl J Med. 1999; 340: 493-501
        • Sieradzki K.
        • Roberts R.B.
        • Haber S.W.
        • Tomasz A.
        The development of vancomycin resistance in a patient with methicillin-resistant Staphylococcus aureus infection.
        N Engl J Med. 1999; 340: 517-523
        • Hiramatsu K.
        Vancomycin resistance in staphylococci.
        Drug Resist Updates. 1998; 1: 135-150
        • Haraga I.
        • Nomura S.
        • Nagayama A.
        The effects of vancomycin and β-lactam antibiotics against vancomycin low-level or intermediately resistant Staphylococcus aureus.
        N Engl J Med. 1999; 341: 1624-1625
        • Hanaki H.
        • Ohkawa S.
        • Inaba Y.
        • Hashimoto T.
        • Hiramatsu K.
        Development of a medium (Mu-3) for detection of heterovancomycin resistant MRSA (hetero-VRSA).
        ([abstract C 132])in: Abstracts of the 38th Interscience Conference on Antimicrobial Agents and Chemotherapy, San Diego, CA American Society for Microbiology, Washington, DC1998: 106
        • Hanaki H.
        • Inaba Y.
        • Sasaki K.
        • Hiramatsu K.
        A novel method detecting Staphylococcus aureus heterogeneously resistant to vancomycin (hetero-VRSA).
        Jpn J Antibiot. 1998; 51: 521-530
        • Wada A.
        • Ohta H.
        • Kulthanan K.
        • Hiramatsu K.
        Molecular cloning and mapping of 16S–23S rRNA gene complexes of Staphylococcus aureus.
        J Bacteriol. 1993; 175: 7483-7487
        • Tenover F.C.
        • Arbeit R.D.
        • Goering R.V.
        • et al.
        Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing.
        J Clin Microbiol. 1995; 33: 2233-2239
        • National Committee for Clinical Laboratory Standards
        Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically.
        in: Approved standard M7-A4. 4th edn. NCCLS, Villanova, Pennsylvania1997
        • Gustafson J.
        • Strassle A.
        • Hächler H.
        • Kayser F.H.
        • Berger-Bächi B.
        The femC locus of Staphylococcus aureus required for methicillin resistance includes the glutamine synthetase operon.
        J Bacteriol. 1994; 176: 1460-1467
        • Berger-Bachi B.
        • Strassle A.
        • Kayser F.H.
        Characterization of an isogenic set of methicillin-resistant and susceptible mutants of Staphylococcus aureus.
        Eur J Clin Microbiol. 1986; 5: 697-701
        • Climo M.W.
        • Patron R.L.
        • Archer G.L.
        Combinations of vancomycin and β-lactams are synergistic against staphylococci with reduced susceptibilities to vancomycin.
        Antimicrob Agents Chemother. 1990; 43: 1747-1753
        • Hiramatsu K.
        • Kondo N.
        • Ito T.
        Genetic basis for molecular epidemiology of MRSA.
        J Infect Chemother. 1996; 2: 117-129
        • Torres J.R.
        • Sanders C.V.
        • Lewis A.C.
        Vancomycin concentration in human tissues: preliminary report.
        J Antimicrob Chemother. 1979; 5: 475-477
        • Niitsuma K.
        • Saito M.
        Vancomycin inhalation therapy—a pharmacokinetic and clinical study of vancomycin.
        Antibiot Chemother. 1996; 122: 123-135
        • Hanaki H.
        • Kuwahara-Arai K.
        • Boyle-Vavra S.
        • Daum R.S.
        • Labischinski H.
        • Hiramatsu K.
        Activated cell-wall synthesis is associated with vancomycin resistance in methicillin resistant Staphylococcus aureus clinical strains Mu3 and Mu50.
        J Antimicrob Chemother. 1998; 42: 199-209
        • Norrby S.R.
        • Alestig K.
        • Ferber F.
        • et al.
        Pharmacokinetics and tolerance of N-formimidoyl thienamycin (MK0787) in humans.
        Antimicrob Agents Chemother. 1983; 23: 293-299
        • Boucher B.A.
        • Kuhl D.A.
        • Hickerson W.L.
        Pharmacokinetics of systemically administered antibiotics in patients with thermal injury.
        Clin Infect Dis. 1992; 14: 458-463
        • Kaatz G.W.
        • Seo S.M.
        • Dorman N.J.
        • Lerner S.A.
        Emergence of teicoplanin resistance during therapy of Staphylococcus aureus endocarditis.
        J Infect Dis. 1990; 162: 103-108
        • Shlaes D.M.
        • Shlaes J.H.
        Teicoplanin selects for Staphylococcus aureus that is resistant to vancomycin.
        Clin Infect Dis. 1995; 20: 1071-1073
        • Waldvogel F.A.
        New resistance in Staphylococcus aureus.
        N Engl J Med. 1999; 340: 556-557