Mycobacterium mucogenicum bacteremia in immune-compromised patients, 2008-2013

Mycobacterium mucogenicum (MM) is a rapidly growing nontuberculous mycobacterium that may rarely cause bacteremia in immune-compromised hosts. All MM cases from 2008 to 2013 were analyzed across 4 risk groups: stem cell transplantation (SCT), hematologic malignancy, solid tumors, and others. Descriptive analysis was performed, as well as comparative analysis of neutropenic patients (absolute neutrophil count ≤1000/μL) with nonneutropenic patients. Of 39 MM cases, 27 patients had undergone SCT. Neutropenia was present in 12 patients. There was a significant difference in the presence of fever at the time of MM bacteremia between neutropenic and nonneutropenic groups (92% versus 42%; P = 0.005). Central venous catheter (CVC) was present in 33 cases. All patients were treated with >1 antibiotic. Most frequently used combination antibiotic regimen involved clarithromycin and amikacin. Median duration of antibiotic treatment was 42 days. Bacteremia resolved in all cases with CVC removal and combination antibiotic treatment.