Rapidly growing Nontuberculous Mycobacterial (NTM) prosthetic infections are sporadically identified in the literature. Since the taxonomic identification of Mycobacterium goodii in 1999, only 11 patient cases have been published, including 3 prosthetic joint infections (PJI). We present 2 additional cases of PJI from M. goodii at a community hospital within a 9-month period.
The prosthetic knee infections occurred in May 2012 and February 2013. Patient A was a 67 year-old healthy female. Patient B was a 70 year-old male with a history of diabetes, gout and hypertension. Patient A developed pain, redness and a blister at the distal aspect of the incision at 9 weeks status-post arthroplasty. Patient B developed pain, swelling and stiffness at 3 weeks status-post arthroplasty. Both patients were readmitted for arthrotomy, irrigation and debridement. Surgical site cultures tested positive for Acid Fast Bacilli (AFB), and both were identified as M. goodii by High Performance Liquid Chromotography. Antimicrobial treatment was guided by susceptibility reports. Patient A received 2 months of intravenous (IV) amikacin, imipenem and levofloxacin then 4 months of oral doxycycline, levofloxacin and trimethoprim/sulfamethoxazole (TMP/SMX). Patient B received 2 months of IV imipenem, levofloxacin and oral TMP/SMX then 4 months of oral ciprofloxacin, doxycycline and TMP/SMX. Both patients underwent revision arthroplasty with subsequent explantation of the prosthetic joint. AFB cultures of aspirated knee fluid were negative 7 months later. Reimplantation was successfully performed 9 months following explantation in both patients. Post-reimplantation, both patients were treated with an additional 2 weeks of IV and 6 weeks of oral antimicrobials with no further recurrence.
M. goodii is an uncommonly identified organism. Prolonged antimicrobial therapy and surgical management with a 2-stage exchange was successful in managing the above two cases of PJI caused by M. goodii. These two cases add to the limited literature available on this particular NTM infection.
L. Costanigro, None