A 55-year-old man with rheumatoid arthritis managed with infliximab presents to clinic with a 3-week history of a painless, indurated ulcer with minimal drainage on his left forearm. He reports a cut sustained while cleaning fish tanks at home 4 weeks prior. Vital signs are stable with a normal body temperature. Physical examination reveals a well-demarcated, violaceous nodule with central ulceration and no regional lymphadenopathy. Culture on standard media at 37°C is negative. Subsequent culture on media incubated at 30°C yields growth of acid-fast positive bacilli. The organism shows optimal growth at temperatures below body temperature and does not grow at 37°C. Which of the following organisms is most likely responsible for this infection?

  1. A)Mycobacterium avium complex
  2. B)Mycobacterium marinumGABARITO
  3. C)Vibrio vulnificus
  4. D)Nocardia asteroides
  5. E)Aeromonas hydrophila

Explicação

Mycobacterium marinum is a nontuberculous mycobacterium that causes cutaneous infections (fish tank granuloma) following inoculation through breaks in skin exposed to freshwater or saltwater environments. The organism is a slow-growing, acid-fast bacillus with... Ver explicação completa e trilha adaptativa →

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