Rapid Diagnosis ofMycobacterium abscessusBacteremia Using Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry

Mycobacterium abscessus was isolated from cultures of seven blood samples from a 64-year-old diabetic female who was admitted due to steroid-unresponsive adrenal insufficiency. The isolates were difficult to identify using the conventional commercial systems, VITEK 2 (bioMerieux, France) or MicroScan (Siemens Healthcare Diagnostics, USA), but were rapidly identified as M. abscessus by a matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based Bruker Biotyper system (Bruker Daltonics, USA). Identification of M. abscessus was confirmed by a reverse hybridizationbased assay (Genotype Mycobacterium CM/AS 12, Hain Lifescience) and direct sequencing of a heatshock protein gene. After removal of her central venous catheter, the patient was successfully treated with a combination therapy comprising clarithromycin, amikacin, cefoxitin, and imipenem. Our findings demonstrate that MALDI-TOF MS can facilitate rapid and accurate identification of M. abscessus from blood cultures, which enables prompt administration of appropriate therapy following catheter removal. (Ann Clin Microbiol 2016;19:77-81)