Non-tuberculous mycobacteria (NTM) are ubiquitous in the environment, and an increasing number of NTM species have been isolated and characterized from both humans and animals, highlighting the zoonotic potential of these bacteria. Host exposure to NTM may impact on cross-reactive immune responsiveness, which may affect diagnosis of bovine tuberculosis and may also play a role in the variability of the efficacy of Mycobacterium bovis BCG vaccination against tuberculosis. In this study we characterized 10 NTM isolates originating from water, soil, nasal swabs of cattle and African buffalo as well as bovine tissue samples. These isolates were previously identified during an NTM survey and were all found, using 16S rRNA gene sequence analysis to be closely related to Mycobacterium moriokaense . A polyphasic approach that included phenotypic characterization, antibiotic susceptibility profiling, mycolic acid profiling and phylogenetic analysis of four gene loci, 16S rRNA, hsp65, sodA and rpoB, was employed to characterize these isolates. Sequence data analysis of the four gene loci revealed that these isolates belong to a unique species of the genus Mycobacterium . This evidence was further supported by several differences in phenotypic characteristics between the isolates and the closely related species. We propose the name Mycobacterium malmesburyense sp. nov. for this novel species. The type strain is WCM 7299T (=ATCC BAA-2759T=CIP 110822T).
Due to its separate position within the genus Arthrobacter in many published phylogenetic trees and its incomplete chemotaxonomic characterization, the type strain of Arthrobacter sanguinis was subjected to analysis of its chemotaxonomic traits including quinone system, polar lipid profile, peptidoglycan structure and fatty acid profile. The fatty acid profile consisted of the major compounds (>10 %) iso-C15 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. It showed a quinone system with the predominating menaquinone MK-9(H2). Both, fatty acid profile and quinone system are in line with the description of the genus Arthrobacter . The peptidoglycan type was l-Lys–l-Ala–Gly (A11.50) which is unique within the genus Arthrobacter sensu lato and also among species of the genus Arthrobacter recently reclassified in the genera Sinomonas , Paenarthrobacter and Pseudarthrobacter . The polar lipid profile was very complex and unique among the group of taxa in containing relatively high proportions of several unidentified lipids. In conclusion from the phylogenetic position and chemotaxonomic distinguishability from related taxa, the reclassification of Arthrobacter sanguinis in a new genus and species, Haematomicrobium sanguinis gen. nov., comb. nov., is proposed. The type strain of the type species is 741T (=CCUG 46407T=DSM 21259T).