RT Journal Article SR Electronic(1) A1 Ghielmetti, Giovanni A1 Rosato, Giuliana A1 Trovato, Alberto A1 Friedel, Ute A1 Kirchgaessner, Constanze A1 Perroulaz, Carmen A1 Pendl, Wolfgang A1 Schulthess, Bettina A1 Bloemberg, Guido V. A1 Keller, Peter M. A1 Stephan, Roger A1 Tortoli, EnricoYR 2020 T1 Mycobacterium helveticum sp. nov., a novel slowly growing mycobacterial species associated with granulomatous lesions in adult swine JF International Journal of Systematic and Evolutionary Microbiology, VO 71 IS 1 OP SP 004615 DO https://doi.org/10.1099/ijsem.0.004615 PB Microbiology Society, SN 1466-5034, AB The occurrence of nontuberculous mycobacteria in different hosts and their implication as obligate or opportunistic pathogens remain mainly unclear. Mycobacteriosis in pigs is usually associated with members of the Mycobacterium avium complex and, in particular, with ‘ Mycobacterium avium subsp. hominissuis ’. Here we describe a novel slow-growing mycobacterial species isolated from lymph nodes obtained from two sows housed in different Swiss farms. The animals presented chronic inappetence and mild diarrhoea. Gross pathology revealed focal caseous lymphadenopathy of the mesenteric lymph nodes. Complete genome sequencing of the two isolates from the two sows was performed. The genomes comprised 5.76 Mb and an average nucleotide identity score of 99.97 %. Whole genome sequence, mycolic acid and matrix-assisted laser desorption ionization-time of flight mass spectrometry analyses revealed that the two isolates were not related to any previously described Mycobacterium species. The closest related species was Mycobacterium parmense , a slow-growing scotochromogenic mycobacterium first isolated from a cervical lymph node of a 3-year-old child. The name proposed for the new species is Mycobacterium helveticum sp. nov. and 16-83T (=DSM 109965T= LMG 2019-02457T) is the type strain., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.004615