Streptacidiphilus bronchialis sp. nov., a ciprofloxacin-resistant bacterium from a human clinical specimen; reclassification of Streptomyces griseoplanus as Streptacidiphilus griseoplanus comb. nov. and emended description of the genus Streptacidiphilus

The taxonomic position of strain 15-057A(T), an acidophilic actinobacterium isolated from the bronchial lavage of an 80-year-old male, was determined using a polyphasic approach incorporating morphological, phenotypic, chemotaxonomic and genomic analyses. Pairwise 16S rRNA gene sequence similarities calculated using the GGDC web server between strain 15-057A(T) and its closest phylogenetic neighbours, Streptomyces griseoplanus NBRC 12779(T) and Streptacidiphilus oryzae TH49(T), were 99.7 and 97.6 %, respectively. The G+C content of isolate 15-057A(T) was determined to be 72.6 mol%. DNA-DNA relatedness and average nucleotide identity between isolate 15-057A(T) and Streptomyces griseoplanus DSM 40009(T) were 29.2 +/- 2.5 % and 85.97 %, respectively. Chemotaxonomic features of isolate 15-D57A(T) were consistent with its assignment within the genus Streptacidiphilus: the whole-cell hydrolysate contained LL-diaminopimelic acid as the diagnostic diamino acid and glucose, mannose and ribose as cell-wall sugars; the major menaquinone was MK9(H-8); the polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, glycophospholipid, aminoglycophospholipid and an unknown lipid; the major fatty acids were anteiso-C-15:0 and iso-C-16:0. Phenotypic and morphological traits distinguished isolate 15-057A(T) from its closest phylogenetic neighbours. The results of our taxonomic analyses showed that strain 15-057A(T) represents a novel species within the evolutionary radiation of the genus Streptacidiphilus, for which the name Streptacidiphilus bronchialis sp. nov. is proposed. The type strain is 15-057A(T) (=DSM 106435(T)=ATCC BAA-2934(T)).