RT Journal Article SR Electronic T1 Genomic diversity and clinical relevance of Mycobacterium simiae JF ERJ Open Research JO erjor FD European Respiratory Society SP 00773-2023 DO 10.1183/23120541.00773-2023 VO 10 IS 2 A1 Wetzstein, Nils A1 Diricks, Margo A1 Andres, Sönke A1 Kuhns, Martin A1 Marschall, Lisa A1 Biciusca, Teodora A1 Smaczny, Christina A1 Friesen, Inna A1 Niemann, Stefan A1 Wichelhaus, Thomas A. YR 2024 UL http://openres.ersjournals.com/content/10/2/00773-2023.abstract AB Introduction Mycobacterium simiae is a slow-growing non-tuberculous mycobacterium that can cause non-tuberculous mycobacterium (NTM) pulmonary disease and extrapulmonary infections. Until now, detailed genomic and clinical characteristics, as well as possible transmission routes of this rare pathogen remain largely unknown.Methods We conducted whole genome sequencing of available M. simiae isolates collected at a tertiary care centre in Central Germany from 2006 to 2020 and set them into context with publicly available M. simiae complex sequences through phylogenetic analysis. Resistance, virulence and stress genes, as well as known Mycobacteriaceae plasmid sequences were detected in whole genome raw reads. Clinical data and course were retrieved and correlated with genomic data.Results We included 33 M. simiae sensu stricto isolates from seven patients. M. simiae showed low clinical relevance with only two patients fulfilling American Thoracic Society (ATS) criteria in our cohort and three receiving NTM-effective therapy. The bacterial populations were highly stable over time periods of up to 14 years, and no instances of mixed or re-infections with other strains of M. simiae were observed. Clustering with <12 single nucleotide polymorphisms distance was evident among isolates from different patients; however, proof for human-to-human transmission could not be established from epidemiological data.Conclusion Overall, the available sequence data for M. simiae complex was significantly extended and new insights into its pathogenomic traits were obtained. We demonstrate high longitudinal genomic stability within single patients. Although we cannot exclude human-to-human transmission, we consider it unlikely in the light of available epidemiological data.Mycobacterium simiae is a rare cause of NTM pulmonary disease. This study demonstrates high longitudinal genomic stability of the pathogen, as well as low clinical relevance in this cohort. https://bit.ly/3SFl9kL