Mycobacterium avium

Mycobacterium avium is a slow-growing, rod-shaped bacterium that belongs to the genus Mycobacterium. Together with Mycobacterium intracellulare, this Gram-positive pathogen belongs to the Mycobacterium avium complex (MAC) and to the group of non-tuberculous mycobacteria (NTM).

An Infection with Mycobacterium avium can cause symptoms similar to those of tuberculosis:

  • Pneumonia with persistent cough, feeling of weakness, and weight loss

  • Fever

  • Lymphadenopathy (abnormal swelling of lymph nodes)

An increased risk of disease or complications exists for individuals with pre-existing conditions whose immune system is already weakened, such as patients with cystic fibrosis.

Mycobacterium avium occurs ubiquitously, especially in water and soil. The bacteria belong to the biofilm formers.

Relevance of pathogen in transmission in endoscopy

  • Gastroenterology: Not relevant

  • Pulmonology: Very high

  • Ear, nose, and throat: High

  • Urology: Not relevant

Relevance for endoscope surveillance

  • High concern organism

Transmission route

The pathogen is transmitted in the air, through contaminated food and water, and in biofilm.

Non‐tuberculous mycobacteria (NTM), such as Mycobacterium avium, can also be spread and transmitted in healthcare facilities through water. The water used for final rinsing of the endoscope must therefore be microbiologically controlled to prevent a recontamination of the endoscope.

Resistance to antibiotics

Mycobacterium avium exhibits high resistance to most antibiotics. In the case of monotherapies, rapid development of resistance can occur.

Sources and further readings

  1. Busatto C et al Mycobacterium avium: an overview, Volume 114, January 2019, Pages 127–134.

  2. Gries O, Ly T: Infektologie – Kompendium humanpathogener Infektionskrankheiten und Erreger, Springer-Verlag Berlin Heidelberg 2019.

  3. Kovaleva J et al. Transmission of Infection by Flexible Gastrointestinal Endoscopy and Bronchoscopy, Clin Microbiol Rev. 2013 Apr;26(2):231-54.

  4. To K. et al. General Overview of Nontuberculous Mycobacteria Opportunistic Pathogens: Mycobacterium avium and Mycobacterium abscessus, J. Clin. Med. 2020, 9(8), 2541.