Pulmonary Mycobacterium chelonae infection

Pulmonary Mycobacterium chelonae infection is a type of pulmonary non-tuberculous mycobacterial infection where the causative organism is Mycobacterium chelonae.

Pathology

M. chelonae is classified as rapidly growing mycobacterium (RGM), class IV in the Runyon classification.

Radiographic features

CT

The imaging spectrum can include one or a combination of:

• small pulmonary nodules: according to one study
  • smaller than 3 mm: 83%
  • 3-10 mm: 79%
  • greater than 10 mm: 7%
• areas of pulmonary consolidation
• bronchiectasis
• pulmonary cavities: may have an upper lobe predilection
• bronchial wall thickening

Treatment and prognosis

M. chelonae are considered uniformly resistant to cefoxitin. Agents such as imipenem are preferred instead.

History and etymology

M. chelonae is thought to have been first isolated from a turtle by Friedmann in 1903, who referred to it as "turtle tubercle bacillus".