Pulmonary mycobacteriosis caused by rifampicin-resistant Mycobacterium szulgai

When and how to treat pulmonary non-tuberculous mycobacterial diseases

Non-tuberculous mycobacteria are ubiquitous environmental organisms that have been recognized as a cause of pulmonary infection for over 50 years. Traditionally patients have had underlying risk factors for development of disease; however, the proportion of apparently immunocompetent patients involved appears to be rising. Not all patients culture-positive for mycobacteria will have progressive disease, making the diagnosis difficult, though criteria to aid in this process are available. The two main forms of disease are cavitary disease (usually involving the upper lobes) and fibronodular bronchiectasis (predominantly middle and lingular lobes). For patients with disease, combination antibiotic therapy for 12-24 months is generally required for successful treatment, and this may be accompanied by drug intolerances and side-effects. Published success rates range from 30% to 82%. As the progression of disease is variable, for some patients, attention to pulmonary hygiene and underlying diseases without immediate antimycobacterial therapy may be more appropriate. Surgery can be a useful adjunct, though is associated with risks. Randomized controlled trials in well-described patients would provide stronger evidence-based data to guide therapy of non-tuberculous mycobacteria lung diseases, and thus are much needed.

Mycobacterium szulgaiin a Patient with Advanced Acquired Immunodeficiency Syndrome: An Unusual Pathogen with Unusual Multidrug Resistance

A 37-year-old Hispanic man with advanced acquired immunodeficiency syndrome developed extensive pulmonary disease with persistent cough, fever, night sweats, worsening dyspnea, and weight loss. Sputum samples showed scant growth of acid-fast bacilli. He failed to respond to the standard tuberculosis regimen of isoniazid, rifampin, ethambutol, and pyrazinamide. Subsequently, Mycobacterium szulgai was identified, and susceptibility tests showed it to be resistant to all four of those agents. Therapy was changed to clarithromycin, doxycycline, ciprofloxacin, and amikacin. Within 2 weeks, the patient's condition improved significantly, and 6 months after treatment, extensive pulmonary infiltrates had nearly resolved. Fewer than 1% of all human isolates of mycobacteria consist of M. szulgai, which is relatively susceptible to standard antimycobacterial agents. To our knowledge, this is the first reported case of M. szulgai with resistance to all primary antituberculosis drugs.

Pulmonary nontuberculous mycobacterial infection caused by Mycobacterium szulgai in a young healthy woman

A 20-year-old woman with no history of pulmonary disease had no symptom and her chest CT scans demonstrated adhesive small multiple nodules in the bronchial lung biopsy specimen showed epithelioid cell granuloma containing Langhans giant cells, therefore she was diagnosed as pulmonary mycobacteriosis caused by M. szulgai. This is the youngest case of this rare condition occurring in a healthy subject without underlying pulmonary diseases.