RESUMO
Three Legionella-like strains, designed km488T, km489 and km521, were isolated from freshwater samples in China. Cells were Gram-stain-negative, rod-shaped and non-spore-forming. Growth was observed on BCYEα agar, but not on BCYEα agar without l-cysteine, chocolate agar with PolyViteX or Columbia blood agar. The major fatty acids (>5â%) of strains km488T, km489 and km521 were C16â:â0, anteiso-C15â:â0, iso-C16â:â0 and anteiso-C17â:â0. The mip gene sequences (574 nt) showed the isolates were almost identical with more than 99.7â% sequence similarities, and closely matched to L. gormanii ATCC 33297T with 95.4-95.6â% sequence similarities. Phylogenetic analyses based on concatenated gene (16S rRNA, mip, rpoB and rnpB) sequences indicated that the isolates formed a distinct cluster along with L. gormanii within the genus Legionella. Matrix-assisted laser desorption ionization time-of-flight analyses also demonstrated a clear separation between the isolates and other closely and distantly related Legionella species. DNA-DNA hybridization studies demonstrated that the isolates were closely related (92.0â-95.0â% DNA-DNA relatedness) but differentiated from their phylogenetic neighbours (<70â% DNA-DNA relatedness). The whole genome of km488T was sequenced, and showed a G+C content of 37.8âmol%. Based on the findings from this polyphasic taxonomic study, the isolates are considered to represent a single novel species, for which the name Legionella qingyii sp. nov. is proposed. The type strain is km488T (KCTC 15636T=CCTCC AB 2018025T=NRBC 113223T).