Mycobacterium intermedium

Mycobacterium intermedium is a rarely identified nontuberculous mycobacterium (NTM) that can cause infections in both healthy and immunocompromised individuals.

Few isolated cases of M. intermedium infection have been reported, making it difficult for clinicians to recognize corresponding clinical disease.

Reported chronic granulomatous dermatitis in a patient caused by Mycobacterium intermedium. The infection was associated with exposure to a whirlpool at home (see also Whirlpool Dermatitis).

Furthermore, cases with chronic Mycobacterium intermedium infections, also NTM mixed infections with this pathogen are reported. Mostly as nosocomial infection after surgical procedures.

Mixed infections with multiple species of nontuberculous mycobacteria (NTM) are difficult to detect and treat. Current conventional molecular methods for detecting mixed infections are limited due to their low specificity. Recently, whole genome sequencing (WGS) analyses have been successfully used to detect and identify NTMs and mixed NTM infections (Dohál M et al. 2021; Khieu V et al. 2012).

Case Report:

46-year-old woman who developed multiple abscesses on the lower anterior abdominal wall (over a previous appendectomy scar) over the past 2 years. Microscopy and culture of the pus discharge were performed to isolate and identify the causative agent. Initially unsuccessful. Only a whole genome sequencing (WGS) GenoType Mycobacterium CM/AS test revealed evidence of a mixed infection with Mycobacterium szulgai and M. intermedium. The patient was treated with a combination of rifampicin 600 mg once daily, ethambutol 600 mg once daily, and clarithromycin 500 mg twice daily after surgical rehabilitation (Singh AK et al. 2015).

1. Dohál M et al (2021) Whole Genome Sequencing in the Management of Non-Tuberculous Mycobacterial Infections. Microorganisms 9: 2237.
2. Edson RS et al (2006) Mycobacterium intermedium granulomatous dermatitis from hot tub exposure. Emerg Infect Dis 12:821-823.
3. Esteban, J et al. (2012) Current treatment of nontuberculous mycobacteriosis: An update. Expert Opin. Pharm 13, 967-986.
4. Khieu V et al. (2012) Whole-genome sequencing analysis to identify infection with multiple species of nontuberculous mycobacteria. Pathogens 10:879.
5. Singh AK et al (2015) Mixed Cutaneous Infection Caused by Mycobacterium szulgai and Mycobacterium intermedium in a Healthy Adult Female: A Rare Case Report. Case Rep Dermatol Med 2015:607519.
6. Sood A et al. (2007) Hypersensitivity pneumonitis-like granulomatous lung disease with nontuberculous mycobacteria from exposure to hot water aerosols. Environ Health Perspect. 115:262-266.