Current Microbiology

, Volume 56, Issue 6, pp 558–562

Aminoglycoside-Resistance Mechanisms in Multidrug-Resistant Staphylococcus aureus Clinical Isolates



Aminoglycoside resistance in six clinically isolated Staphylococcus aureus was evaluated. Genotypical examination revealed that three isolates (HLGR-10, HLGR-12, and MSSA-21) have aminoglycoside-modifying enzyme (AME) coding genes and another three (GRSA-2, GRSA-4, and GRSA-6) lacked these genes in their genome. Whereas isolates HLGR-10 and HLGR-14 possessed bifunctional AME coding gene aac(6′)-aph(2′′), and aph(3′)-III and showed high-level resistance to gentamycin and streptomycin, MSSA-21 possessed aph(3′)-III and exhibited low resistance to gentamycin, streptomycin, and kanamycin. The remaining three isolates (GRSA-2, GRSA-4, and GRSA-6) exhibited low resistance to all the aminoglycosides because they lack aminoglycoside-modifying enzyme coding genes in their genome. The transmission electron microscopy of the three isolates revealed changes in cell size, shape, and septa formation, supporting the view that the phenomenon of adaptive resistance is operative in these isolates.


  1. 1.
    Asseray N, Caillon J, Roux N, et al. (2002) Different aminoglycoside-resistant phenotypes in a rabbit Staphylococcus aureus endocarditis infection model. Antimicrob Agents Chemother 46:1591–1593PubMedCrossRefGoogle Scholar
  2. 2.
    Benveniste R, Davies J (1973) Mechanisms of antibiotic resistance in bacteria. Annu Rev Biochem 42:471–506PubMedCrossRefGoogle Scholar
  3. 3.
    Bryan LE (1990) Two forms of antimicrobial resistance: bacterial persistence and positive function resistance. J Antimicrob Chemother 23:817–823CrossRefGoogle Scholar
  4. 4.
    Bryan LE, Kwan S (1983) Roles of ribosomal binding, membrane potential, and electron transport in bacterial uptake of streptomycin and gentamycin. Antimicrob Agents Chemother 23:835–845PubMedGoogle Scholar
  5. 5.
    Dornbusch K, Miller GH, Hare RS, Shaw KJ, ESGAR Study Group (1990) Resistance to aminoglycoside antibiotics in gram-negative bacilli and staphylococci isolated from blood. Report from a European collaborative study. J Antimicrob Chemother 26:131–144PubMedCrossRefGoogle Scholar
  6. 6.
    Edson RS, Terrell CL (1999) The aminoglycosides. Mayo Clin Proc 74:519–528PubMedCrossRefGoogle Scholar
  7. 7.
    Fani R, Damiani G, Di Serio Gallori E, Grifoni A, Bazzicalupo M (1993) Use of random amplified polymorphic DNA (RAPD) for generating specific DNA probes for microorganisms. Mol Ecol 2:243–250PubMedCrossRefGoogle Scholar
  8. 8.
    Neumann G, Veeranagouda Y, Karegoudar TB, et al. (2005) Cells of Pseudomonas putida and Enterobacter sp. adapt to toxic organic compounds by increasing their size. Extremophiles 9:163–168PubMedCrossRefGoogle Scholar
  9. 9.
    Hancock REW (1981) Aminoglycoside uptake and mode of action with special reference to streptomycin and gentamycin. J Antimicrob Chemother 8:249–276PubMedCrossRefGoogle Scholar
  10. 10.
    Ida T, Okamoto R, Shimauchi C, Okubo T, Kuga A, Inoue M (2001) Identification of aminoglycoside-modifying enzymes by susceptibility testing: epidemiology of methicillin-resistant Staphylococcus aureus in Japan. J Clin Microbiol 39:3115–3121PubMedCrossRefGoogle Scholar
  11. 11.
    Mandel LJ, Murphy E, Steigbigel NH, Miller MH (1984) Gentamycin uptake in Staphylococcus aureus possessing plasmid-encoded, aminoglycoside-modifying enzymes. Antimicrob Agents Chemother 26:563–569PubMedGoogle Scholar
  12. 12.
    Miller MH, Edberg SC, Mandel LJ, Behar CF, Steigbigel NH (1980) Gentamycin uptake in wild type and aminoglycoside-resistant small-colony mutants of Staphylococcus aureus. Antimicrob Agents Chemother 18:722–729PubMedGoogle Scholar
  13. 13.
    Moorman DR, Mandeli GL (1981) Characteristics of rifampin-resistant variants obtained from clinical isolates of Staphylococcus aureus. Antimicrob Agents Chemother 20:709–713PubMedGoogle Scholar
  14. 14.
    Phillips I, Shannon K (1984) Aminoglycoside resistance. Br Med Bull 40:28–35PubMedGoogle Scholar
  15. 15.
    Phillips I, King A, Shannon K (1986) Prevalence and mechanisms of aminoglycoside resistance a ten-year study. Am J Med 80:48–55PubMedCrossRefGoogle Scholar
  16. 16.
    Poole K (2005) Aminoglycoside resistance in Pseudomonas aeruginosa. Antimicrob Agents Chemother 49:479–487PubMedCrossRefGoogle Scholar
  17. 17.
    Raju S, Gururaj Rao, Patil SA, Chandrakanth Kelmani R (2007) Increase in cell size and acid tolerance response in a stepwise adapted methicillin resistant Staphylococcus aureus mutant. World J Microbiol Biotechnol 23:1227–1232CrossRefGoogle Scholar
  18. 18.
    Raju S, Kelmani Chandrakanth R, Patil SA (2007) High level oxacillin and gentamycin resistance with reduced susceptibility to vancomycin in Staphylococcus aureus carrying mecA and femA gene complex. Curr Microbiol 54:429–434PubMedCrossRefGoogle Scholar
  19. 19.
    Rouch DA, Byrne ME, Kong YC, Skurray RA (1987) The aacA-aphD gentamycin and kanamycin resistance determinant of Tn4001from Staphylococcus aureus: expression and nucleotide sequence analysis. J Gen Microbiol 133:3039–3052PubMedGoogle Scholar
  20. 20.
    Shaw KJ, Rather PN, Hare RS, Miller GH (1993) Molecular genetics of aminoglycoside resistance genes and familial relationships of the aminoglycoside-modifying enzymes. Microbiol Rev 57:138–163PubMedGoogle Scholar
  21. 21.
    Shelburne SA, Musher DM, Hulten K, et al. (2004) In vitro killing of community-associated methicillin-resistant Staphylococcus aureus with drug combinations. Antimicrob Agents Chemother 48:4016–4019PubMedCrossRefGoogle Scholar
  22. 22.
    Shlaes DM, Etter L, Gutmann L (1991) Synergistic killing of vancomycin-resistant enterococci of classes A, B, and C by combinations of vancomycin, penicillin, and gentamycin. Antimicrob Agents Chemother 35:776–779PubMedGoogle Scholar
  23. 23.
    Ubukata K, Yamashita N, Gotoh A, Konno M (1984) Purification and characterization of aminoglycoside-modifying enzymes from Staphylococcus aureus and Staphylococcus epidermidis. Antimicrob Agents Chemother 25:754–759PubMedGoogle Scholar
  24. 24.
    Vanhoof R, Hannecart-Pokorni E, Content J (1998) Nomenclature of genes encoding aminoglycoside-modifying enzymes. Antimicrob Agents Chemother 42:483PubMedCrossRefGoogle Scholar
  25. 25.
    You I, Kariyama R, Zervos MJ, Kumon H, Chow JW (2000) In-vitro activity of arbekacin alone and in combination with vancomycin against gentamycin- and methicillin-resistant Staphylococcus aureus. Diagn Microbiol Infect Dis 36:37–41PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • R. Kelmani Chandrakanth
    • 1
  • S. Raju
    • 1
    • 2
  • S. A. Patil
    • 3
  1. 1.Department of BiotechnologyGulbarga UniversityGulbargaIndia
  2. 2.Department of Microbiology and Cell BiologyIndian Institute of ScienceBangaloreIndia
  3. 3.Department of NeuromicrobiologyNIMHANSBangaloreIndia

Personalised recommendations