An injection abscess due to M. fortuitum: A rare case report

An iatrogenic injection abscess is usually easy to treat if caused by aerobic bacteria but some rapidly growing mycobacteria (RGM), namely, Mycobacterium fortuitum, M. chelonae, and M. abscessus are associated with postinjection abscess and may cause delayed wound healing. RGM can cause mild localized cellulitis or abscess to osteomyelitis following penetration injuries or unsafe injection practices. A 7-year-old girl was presented to pediatric surgery OPD with abscess formation over the right buttock. Incision and drainage from abscess were performed in OPD and pus sample was sent for aerobic bacterial culture and sensitivity. On gram stain plenty of pus cells with no microorganism were seen and growth on blood agar after 48 h of aerobic incubation at 37°C showed small off-white pinpoint, smooth butyrous waxy colonies. Smear prepared from blood agar showed uniformly stained short, slender, faintly stained gram-positive bacilli, for which acid-fast staining (1% and 20% H₂SO₄) was performed that showed acid-fast bacilli. The isolate was further identified by the molecular method and was confirmed to be Mycobacterium fortuitum by genotype Mycobacterium CM VER 1.0 (HAIN LIFESCIENCE, BioMerieux India Pvt. Ltd.).