Catheter-related bloodstream infection by a newly proposed “Mycobacterium toneyamachuris” in a boy with B-cell precursor acute lymphoblastic leukemia

This report describes a 6-year-old boy who developed non-tuberculosis mycobacteria (NTM) catheter-related bloodstream infection (CRBSI) during treatment for B-cell precursor acute lymphoblastic leukemia. A Hickman catheter was inserted before starting treatment. He developed a fever during chemotherapy, and blood culture was drawn from the catheter. Blurred Gram-positive bacilli were found in Gram stain, looked positive in Ziehl–Neelsen stain, and were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry as Mycobacterium mucogenicum phocaicum group. The administration of clarithromycin and amikacin was started and the Hickman catheter was removed. We performed genomic sequencing to obtain accurate identification, demonstrating that this microorganism was identified as “M. toneyamachuris” calculated by the average nucleotide identity index. Finally, a clinical diagnosis of CRBSI caused by “M. toneyamachuris” was made. Our findings suggest that genomic sequencing is available for the accurate identification of NTM species.