The incidence of non-tuberculous mycobacterial pulmonary disease (NTM-PD) is increasing, and the identification of new Mycobacterium species is also increasing. We describe the first case of chronic pulmonary infection caused by a novel Mycobacterium species. A 66-year-old man was referred to our hospital with a several-week history of low-grade fever and productive cough. An acid-fast bacillus smear test of the sputum revealed positive. Polymerase chain reaction (PCR) for Mycobacterium intracellulare was positive; however, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) failed to identify the strain. The isolated culture was referred for further genotypic identification and was confirmed to be a novel species. Combination therapy with clarithromycin, rifampicin, and sitafloxacin was started. Despite treatment, the patient’s condition gradually worsened during the subsequent follow-up period. We describe the first case of NTM-PD with a novel Mycobacterium species. Mycobacterium habikinoensis is a novel species closely related to Mycobacterium colombiense but with distinct characteristics. Further investigation is required to clarify its pathogenicity, antimicrobial susceptibility, and clinical significance in human infections.
Maeda et al. (Fri,) studied this question.