Mycobacterium haemophilum

Description

• Nonpigmented and rough to smooth colonies.

• Media have to be supplemented with 0.4% haemoglobin or 60 μM hemin or 15 mg/ml ferric ammonium citrate respectively, but not with FeCl₃ or catalase.
• Slow growth on Löwenstein-Jensen media or Middlebrook 7H10 agar at 32 °C within 2–4 weeks.
• Growth slower at 25 °C and 35 °C and absent at 37 °C.
• Strictly intracellular growth in tissue cultures of fibroblasts.

• Unique among mycobacteria in its requirement for hemin or ferric ammonium citrate for growth.

Pathogenesis

• Infects patients with suppressed immune systems.
• Clinical presentation: multiple skin nodules occurring in clusters or without definitive pattern, commonly involving the extremities. Abscesses, draining fistulas and osteomyelitis may be associated with the nodules. Paediatric patients with localised cervical lymphadenopathy.
• Biosafety level 2

  Type strain