Osteomyelitis due to multiple rare infections in a patient with idiopathic CD4 lymphocytopenia

A 26-year-old male patient presented with features suggestive of osteomyelitis involving the entire left femur, hip joint and knee joint. Culture from the debrided tissue grew Acinetobacter spp. and he was treated with sensitivity based antibiotics but the symptoms did not resolve. The synovial biopsy showed multinucleated giant cells and acid fast bacilli on Ziehl Neelsen stain. Cartridge based nucleic acid amplification test (GeneXpert) was negative. The Mycobacteria growth indicator tube culture was found to be positive for Mycobacterium abscessus. The patient was started on imipenem, amikacin and macrolide based therapy. There was partial response initially but the patient worsened again. A girdle stone arthroplasty with cemented nail (with tobramycin) insertion after debridement of the infected tissue was done. Potassium hydroxide (KOH) mount from the debridement sample was found to be positive for aseptate hyphae suggestive of mucormycosis. He was treated with liposomal amphotericin B. He was evaluated for immunodeficiency in view of multiple atypical infections and was found to have a low CD4 count. The patient was discharged on amikacin, azithromycin, trimethoprimsulfamethoxazole and posaconazole. Follow up showed considerable resolution both clinically and radiologically. To our knowledge, this is the first reported case of osteomyelitis with co-infection of Acinetobacter spp., M. abscessus and mucormycetes. We report this case to highlight the possibility of multiple rare infections in patients with immunodeficiency. Also, atypical complicated bone infections, such as Mycobacterium abscessus and mucormycetes might require combined medical and surgical treatment.