Mycolicibacter arupensis

Mycolicibacter arupensis (formerly Mycobacterium arupense) is a slowly growing mycobacterium first isolated from soil and human sputum samples in Spain.^[1] Etymology: arupense, pertaining to the ARUP Institute for Clinical and Experimental Pathology, where the type strain was characterized.

Description

Microscopy

• Gram-positive, nonmotile and acid-fast rods (1–3 µm × 0.5–0.7 µm), mostly strong acid-fast.

Colony characteristics

• Colonies are eugonic, rough and nonpigmented.

Physiology

• Colonies occur within 5 days at 30 °C (optimum temperature, no growth at 45 °C) on Löwenstein-Jensen medium and on Middlebrook 7H10 agar and slowly (10–12 days) at 37 °C; no growth occurs at 42 °C.
• No growth on MacConkey agar without crystal violet.
• The type strain is resistant to D-cycloserine, streptomycin, isoniazid (0.1 and 1 mg/L), rifampin, and thiacetazone and is susceptible to isoniazid (10 mg/L), kanamycin, and capreomycin.

Pathogenesis

There are emerging reports of human pathogenesis caused by M. arupensis. Pulmonary infection and tenosynovitis have been documented. A recent case of recurrent soft tissue abscess caused by M. arupensis has been identified.

References