Tsukamurella asaccharolytica sp. nov., Tsukamurella conjunctivitidis sp. nov. and Tsukamurella sputi sp. nov., isolated from patients with bacteraemia, conjunctivitis and respiratory infection in Hong Kong

Three bacterial strains, HKU70 , HKU71 and HKU72 , were isolated from the conjunctival swab, blood and sputum samples of three patients with conjunctivitis, bacteraemia and respiratory infection, respectively, in Hong Kong. The three strains were aerobic, Gram-stain positive, catalase-positive, non-sporulating and non-motile bacilli and exhibited unique biochemical profiles distinguishable from currently recognized species. 16S rRNA, , and gene sequence analyses revealed that the three strains shared 99.6-99.9, 94.5-96.8, 95.7-97.8 and 97.7-98.9 % nucleotide identities with their corresponding closest species respectively. DNA-DNA hybridization confirmed that they were distinct from other known species of the genus (26.2±2.4 to 36.8±1.2 % DNA-DNA relatedness), in line with results of genome-to-genome comparison (32.2-40.9 % Genome-to-Genome Distance Calculator and 86.3-88.9 % average nucleotide identity values]. Fatty acids, mycolic acids, cell-wall sugars and peptidoglycan analyses showed that they were typical of members of . The G+C content determined based on the genome sequence of strains HKU70 , HKU71 and HKU72 were 69.9, 70.2 and 70.5 mol%, respectively. Taken together, our results supported the proposition and description of three new species, i.e. HKU70 (=JCM 33387 =DSM 109106 ) sp. nov., HKU71 (=JCM 33388 =DSM 109107 ) sp. nov. and HKU72 (=JCM 33389 =DSM 109108 ) sp. nov.