Treating Primary Arthroprosthesis Infection Caused by Mycobacterium abscessus subsp. abscessus

Prosthetic joint infections (PJI) caused by nontuberculous mycobacteria are very rare, and results of treatment can be unpredictable. A 72-year-old female underwent hip replacement after an accidental fall in a local hospital in Santo Domingo. The postoperative period was uneventful except for a traumatic wound near the surgical scar. PJI caused by Mycobacterium abscessus subsp. abscessus was diagnosed 6 months later. A two-stage reimplantation was performed after a 3-month period of aetiology-directed therapy, including amikacin, imipenem, and clarithromycin. M. abscessus isolate was reported to be resistant to clarithromycin when incubation was protracted for 14 days and to harbour the gene erm(41). The patient manifested major side effects to tigecycline. At reimplant, microbiologic investigations resulted negative. Overall, medical treatment was continued for a 7-month period. When discontinued and at 6-month follow-up, the patient was clinically well, inflammatory markers were normal, and the radiography showed well-positioned prosthesis. Mycobacterium abscessus subsp. abscessus is a very rare cause of PJI, yet it must be included in the differential diagnosis, especially when routine bacteria cultures are reported being negative. Further investigations are needed to determine any correlations between clinical results and in vitro susceptibility tests, as well as the clinical implications of M. abscessus subsp. abscessus harbouring the functional gene erm(41). Moreover, investigations are needed for determine optimal timings of surgery and lengths of medical therapy to improve patient outcome.