Catheter-related bloodstream infection due to Mycobacterium neoaurum in a patient with acute leukemia.

Rapidly growing non-tuberculous mycobacteria (RGM) are a diverse group of organisms usually isolated from the environment, and are associated with infection at several sites. Mycobacterium fortuitum , Mycobacterium chelonae and Mycobacterium abscessus account for the most common RGM associated with infections in humans [1]. Frequently, these pathogens have been associated with soft-tissue infection, endocarditis, pneumonia and keratitis [2]. Rarely, RGM have been implicated in bloodstream infections (BSIs) and catheter exit site infection [3]. Mycobacterium neoaurum is an unusual human pathogen and a very rare cause of BSI mostly in immunocompromised patients [2]. We herein report a patient with leukemia, who developed Mycobacterium neoaurum catheter-related bloodstream infection (CRBSI), after receiving chemotherapy. In addition, we review cases of M. neoaurum from the literature to define management of this rare infection. Lastly, we discuss the usefulness of 16S rRNA gene sequencing for rapid and accurate identification of closely related RGM. A 48-year-old African American man with a history of T-cell acute lymphoblastic leukemia presented for his fourth cycle of chemotherapy with methotrexate and cytarabine. On day 2 of chemotherapy, he developed a temperature of 101 ° F with blood pressure 110/90 mmHg, pulse 72 per min and respirations 14 per min. Th ere was no focus of infection on physical examination, including his port-a-cath site. His white blood cell count was within normal limits, with an absolute neutrophil count (ANC) of 1900 cells/mL. Work-up including blood cultures was performed. With persistent fever, antibiotic therapy with cefepime and vancomycin was initiated. Blood culture obtained via the port-a cath grew gram-positive bacilli in the aerobic bottle, after 5 days of incubation. On day 6 after chemotherapy, the patient became neutropenic. During neutropenia, the fever persisted, and also, blood cultures remained positive despite broad-spectrum antibiotics. His port-a-cath was removed and within 1 day, his fever resolved and bacteremia cleared. Th e organism causing bacteremia was an acid-fast bacillus, identifi ed eventually by 16S rRNA sequencing method as Mycobacterium neoaurum . Antibiotic susceptibility testing was not performed. However, as the patient required further chemotherapy for leukemia, the decision was made to treat him for an extended period with ciprofl oxacin and doxycycline, despite no evidence of pocket or metastatic infection. Th e patient completed 3 months of antibiotic therapy. Th ere was no recurrence of his bacteremia during