Abstract

Background: Mycobacterium abscessus (M. abscessus), a rapidly growing Mycobacterium (RGM) is an emergent cause of soft issue and musculoskeletal infections. Treatment is often complicated by commonly occurring intrinsic and acquired resistance to not only the classical anti-tuberculous agents but also to most currently available antibiotics.
Case Presentation: We present a case of left thumb carpometacarpal (CMC) joint septic arthritis in a 66-year-old American Caucasian woman following an intra-articular steroid injection for osteoarthritis treatment. She did not improve on conventional empirical cellulitis treatment prompting culture and sensitivity assays. Mycobacterium abscessus Deoxyribonucleic acid was detected by real-time polymerase chain reaction (PCR) with additional cultures growing the same organism within a week. Samples were sent to the New York State Department of Health for a full culture and sensitivity profile which demonstrated extensive resistance to antibacterial agents including conventional anti-tuberculous agents.
Conclusion: This case not only highlights the importance of having a high degree of suspicion for M. abscessus in joint and soft tissue infections not improving to commonly used empirical therapies even in low prevalent areas. It also underlines the importance of performing cultures and sensitivity given antibiotic combinations for most RGM infections should be sensitivity guided.

Key words: Septic arthritis, Mycobacterium abscessus, rapidly growing Mycobacterium, case report.