Legionella maioricensis sp. nov., a new species isolated from the hot water distribution systems of a hospital and a shopping center during routine sampling

• Two Legionella- like strains isolated from hot water distribution systems in 2012 have been characterized phenotypically, bio-chemically and genomically in terms of DNA relatedness. Both strains, HCPI- 6T and EUR- 108, exhibited biochemical pheno-typic profiles typical of Legionella species. Cells were Gram-negative motile rods which grew on BCYE alpha agar but not on blood agar and displayed phenotypic characteristics typical of the family Legionellaceae, including a requirement for L-cysteine and testing catalase positive. Both strains were negative for oxidase, urease, nitrate reduction and hippurate negative, and non -fermentative. The major ubiquinone was Q12 (59.4 % HCPI- 6T) and the dominant fatty acids were C16:1 omega 7c (28.4 % HCPI- 6T, 216 % EUR- 108), C16: 0 iso (222.5 % and 213 %) and C15: 0 anteiso (19.5 % and 223.5 %, respectively). The percent G+C content of genomic DNA was determined to be 39.3 mol %. The 16S rRNA gene, mip sequence and comparative genome sequence -based analyses (average nucleotide identity, ANI; digital DNA-DNA hybridization, dDDH; and phylogenomic treeing) demonstrated that the strains represent a new species of the genus Legionella. The analysis based on the 16S rRNA gene sequences showed that the sequence similarities for both strains ranged from 98.8-90.1 % to other members of the genus. The core genome- based phylogenomic tree (protein-concatemer tree based on concatenation of 418 proteins present in single copy) revealed that these two strains clearly form a separate cluster within the genus Legionella. ANI and dDDH values confirmed the distinctiveness of the strains. Based on the genomic, genotypic and phenotypic findings from a polyphasic study, the isolates are considered to represent a single novel species, for which the name Legionella maioricensis sp. nov. is proposed. The type strain is HCPI- 6T (=CCUG 75071T=CECT 30569T).

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Microbiology in the medical area (hsv//eng)

Nyckelord

16S rRNA gene

average nucleotide identity

digital DNA-DNA

hybridization

genome comparison

hot water

Legionella maioricensis

mip

novel species

phylogenomics

polyphasic taxonomy

DNA-DNA hybridization

legionnaires-disease

sequence alignment

pigment

production

genome

pneumophila

algorithm

acid

classification

identification

Microbiology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)