Chronic Pulmonary Disease Caused by Tsukamurella toyonakaense

Abstract

Unidentified Mycobacterium species are sometimes detected in respiratory specimens. We identified a novel Tsukamurella species (Tsukamurella sp. TY48, RIMD 2001001, CIP 111916^T), Tsukamurella toyonakaense, from a patient given a misdiagnosis of nontuberculous mycobacterial pulmonary disease caused by unidentified mycobacteria. Genomic identification of this Tsukamurella species helped clarify its clinical characteristics and epidemiology.

Keywords: Japan; Tsukamurella paurometabola; Tsukamurella toyonakaenses; antimicrobial resistance; bacteria; chronic pulmonary disease; nontuberculous mycobacteria; rapid-growing mycobacteria; tuberculosis and other mycobacteria.

Figure 1

Comparison of chest computed tomography findings over time for patient who had chronic pulmonary disease caused by Tsukamurella toyonakaense. Findings are shown from before Tsukamurella species was detected (A, C, E, and G) and 6 years later (B, D, F, and H). A and B show that nodules in right segment 2 and left segment 6 were unchanged. C and D show that bronchiectasis in lingula had progressed. E and F show that bronchiectasis newly appeared in the middle lobe. G and H show that nodules newly appeared in left segments 8–10.

Figure 2

Maximum-likelihood phylogenetic tree constructed by using 16S rRNA sequences of Tsukamurella spp. and other bacterial species. Bold indicates strain isolated in this study. Reference sequences were obtained from SILVA database (4) release 138 as small subunit reference nonredundant 99 sequences, which showed >98.7% identity with strain TY48. GenBank accession numbers are provided for reference sequences. Scale bar indicates nucleotide substitutions per site.