Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Thu, 25 Apr 2019 23:34:56 Mycobacterium angelicum sp. nov., a non-chromogenic, slow-growing species isolated from fish and related to Mycobacterium szulgai Fazel Pourahmad, 1 Mateja Pate, 2 Matjaz ˇ Ocepek, 2 Emanuele Borroni, 3 Andrea M. Cabibbe, 3 Eleonora Capitolo, 4 Davide Cittaro, 4 Eliana Frizzera, 5 Vlasta Jenc ˇic ˇ, 2 Alessandro Mariottini, 6 Kenji Marumo, 7 Guendalina Vaggelli, 8 Daniela M. Cirillo 3 and Enrico Tortoli 3 Correspondence Enrico Tortoli tortoli.enrico@hsr.it 1 School of Veterinary Medicine, Ilam University, Ilam, Iran 2 National Veterinary Institute, University of Ljubljana, Ljubljana, Slovenia 3 Emerging Bacterial Pathogens Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy 4 Center for Translational Genomics and Bioinformatics, IRCCS San Raffaele Scientific Institute, Milan, Italy 5 Microbiology Unit, General Hospital, Bolzano-Bozen, Italy 6 Diagnostic Genetics Unit, Careggi University Hospital, Florence, Italy 7 Department of Microbiology and Immunology, Showa University, Tokyo, Japan 8 Mycrobiology and Virology Unit, Careggi University Hospital, Florence, Italy The name ‘Mycobacterium angelicum’ dates back to 2003 when it was suggested for a slowly growing mycobacterium isolated from freshwater angelfish. This name is revived here and the novel species is proposed on the basis of the polyphasic characterization of four strains including the original one. The four strains presented 100 % 16S rRNA gene sequence similarity with Mycobacterium szulgai but clearly differed from M. szulgai for the milky white aspect of the colonies. The sequence similarity with the type strain of M. szulgai ranged, in eight additionally investigated genetic targets, from 78.9 to 94.3 %, an evident contrast with the close relatedness that emerged at the level of 16S rRNA gene. The average nucleotide identity between the genomes of M. szulgai DSM 44166 T and strain 126/5/03 T (type strain of the novel species) was 92.92 %, and supported the status of independent species. The confirmation of the name Mycobacterium angelicum sp. nov. is proposed, with strain 126/5/03 T (5CIP 109313 T 5DSM 45057 T ) as the type strain. A close connection exists between mycobacteria and water, both fresh and salt, and this makes infection of aquatic animals quite common. In addition to Mycobacterium marinum, the best-known fish and zoonotic pathogen, a number of other species of the genus Mycobacterium have been reported which are epidemiologically linked to fish (Gauthier & Rhodes, 2009). Mycobacterium shottsii (Rhodes et al., 2003), Mycobacterium montefiorense (Levi et al., 2003), Mycobacterium pseudoshottsii (Rhodes et al., 2005), Mycobacterium salmoniphilum (Whipps et al., 2007) and Mycobacterium stomatepiae (Pourahmad et al., 2008) have all been described following isolation from fish. The name Mycobacterium angelicum was proposed in 2003 for one strain isolated in Slovenia from a freshwater angel- fish (Pterophyllum scalare). Several characteristics suggested Abbreviations: ANI, average nucleotide identity; ITS, internal trans- cribed spacer. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene, hsp65, rpoB, sodA, gyrB, dnaK, secA1, rpoBC and ITS1 seq-uences of strain 126/5/03 T are AM884328, AM902962, KT168289, KT168302, KT168298, KT168305, KT168310, KT168313 and AM902930, respectively. The GenBank/EMBL/DDBJ accession numbers for the hsp65 and gyrB gene sequences of strain JCM 18266 are KC481266 and KT168297, respectively, and those for the dnaK and secA1gene sequences of strain JCM 18267 are KT168306 and KC481266, respectively. The GenBank/EMBL/DDBJ accession numbers for the rpoB, gyrB and ITS1 sequences of Mycobacterium szulgai DSM 44166 T are KT168290, KT168299 and KT168285, respectively. Nine supplementary figures are available with the online Supplementary Material. International Journal of Systematic and Evolutionary Microbiology (2015), 65, 4724–4729 DOI 10.1099/ijsem.0.000642 000642 G 2015 IUMS Printed in Great Britain 4724