12. Final Identification by HPLC

  • Mycobacterium chelonae complex


  • Initially, M. chelonae had two subspecies
    • M. chelonae subspecies chelonae
    • M. chelonae subspecies abscessus
  • 1992, DNA homology studies showed these were two separate species
    • M. chelonae
    • M. abscessus
  • There are major differences between two species

    • M. chelonae
      • usually produces disease in setting of corticosteroid therapy
        • usually disseminated skin disease
      • rarely associated with nosocomial disease
      • highly cefoxitin resistant
    • M. abscessus
      • more virulent
      • cause disease with or without immunosuppression
      • common in nosocomial disease
      • Susceptible to cefoxitin

Breakpoint #5

  • What further information is needed from the laboratory to initiate therapy?