Mycobacterial infection identified with broad-range PCR amplification and suspension array identification

Area of Science:

• Infectious Diseases
• Microbiology
• Dermatology

Background:

• Primary cutaneous infections by Mycobacterium avium-intracellulare are rare in immunocompetent individuals.
• Mycobacterium avium-intracellulare is an environmental bacterium found in various water and soil sources.
• Cutaneous manifestations can present as granulomatous inflammation with neutrophils.

Purpose of the Study:

• To report a case of primary cutaneous Mycobacterium avium-intracellulare infection.
• To highlight the utility of molecular diagnostics for rapid identification of mycobacterial pathogens.
• To emphasize the importance of considering atypical mycobacteria in unexplained skin infections.

Main Methods:

• Histopathological examination of biopsy tissue showing granulomas, inflammation, and acid-fast bacilli.
• Broad-range polymerase chain reaction (PCR) amplification of tissue DNA.
• Suspension array identification for precise pathogen classification.

Main Results:

• The pathogenic organism was identified as Mycobacterium avium-intracellulare using molecular methods.
• Cultures were negative, underscoring the limitations of traditional diagnostic approaches.
• The patient showed clinical improvement after treatment with clarithromycin, rifabutin, and ethambutol.

Conclusions:

• Molecular diagnostics offer a faster and more specific alternative to conventional cultures for identifying Mycobacterium avium-intracellulare.
• Early and accurate diagnosis is crucial for effective management of cutaneous mycobacterial infections.
• This case expands the understanding of Mycobacterium avium-intracellulare's potential to cause primary cutaneous disease in immunocompetent hosts.