MICROBIOLOGY

• Rapidly-growing, hardy, ubiquitous mycobacterium commonly found in the environment, including waters (including municipal tap water), soil and plant matter.
• In vitro drug susceptibility testing should always be sought to guide antimicrobial therapy (susceptibility is unpredictable).
• The lab must differentiate from M. abscessus, which can appear similar in microbiological testing but has different disease patterns and treatments. Before 1992, this organism was lumped into M. abscessus species. Since, M. chelonae is a separate species.
  • Optimal growth is 30–32°C, which can require long incubations.
  • Classified as a rapid grower mycobacterium (RGM), class IV, using the Runyon system.