Mycobacterium abscessus Complex Infections: A Retrospective Cohort Study

Area of Science:

• Infectious Diseases
• Antimicrobial Resistance
• Clinical Microbiology

Background:

• Mycobacterium abscessus group infections present significant global treatment challenges due to multi-drug resistance.
• This study investigates risk factors, treatment strategies, and clinical outcomes in a US cohort.

Purpose of the Study:

• To identify risk factors associated with early treatment failure in Mycobacterium abscessus infections.
• To analyze treatment outcomes and antimicrobial susceptibility patterns.

Main Methods:

• Retrospective cohort study of 108 hospitalized adults with M. abscessus infections.
• Analysis of demographics, comorbidities, infection sources, antimicrobial susceptibility, and clinical outcomes.
• Early treatment failure defined by death or persistent infection within 12 weeks.

Main Results:

• Respiratory infections were most common (54.6%). High in vitro susceptibility to clarithromycin (93.8%), amikacin (93.8%), and tigecycline (89.1%).
• Complete resistance observed for trimethoprim/sulfamethoxazole; low susceptibility to ciprofloxacin (1.6%).
• Early treatment failure occurred in 33.3% of patients, with 15.7% in-hospital mortality. Risk factors included disseminated infection, acute kidney injury, organ transplantation, immunosuppressive therapy, and clarithromycin resistance.

Conclusions:

• Mycobacterium abscessus infections in this cohort had a significant in-hospital mortality rate (15.7%).
• Clarithromycin and amikacin demonstrated favorable in vitro activity, while fluoroquinolones and trimethoprim/sulfamethoxazole showed high resistance.
• Macrolide resistance, immunosuppression, and renal disease were significantly linked to early treatment failure.