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

• Published in: International journal of systematic and evolutionary microbiology Vol. 73; no. 1
• Main Authors: Crespi, Sebastian, Drašar, Vladimír, Salvà-Serra, Francisco, Jaén-Luchoro, Daniel, Piñeiro-Iglesias, Beatriz, Lindemann, Paul Christoffer, Aliaga-Lozano, Francisco, Fernández-Juárez, Victor, Coll-García, Guillem, Moore, Edward R B, Bennasar-Figueras, Antoni
• Format: Journal Article
• Language: English
• Published: England 01.02.2023
• Subjects: Bacterial Typing Techniques; Base Composition; DNA, Bacterial - genetics; Fatty Acids - chemistry; Hospitals; Legionella; Nucleic Acid Hybridization; Phylogeny; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Water Microbiology; Water Supply; average nucleotide identity; Legionella maioricensis; digital DNA–DNA hybridization; mip; genome comparison; hot water; novel species; phylogenomics; 16S rRNA gene; polyphasic taxonomy
• ISSN: 1466-5034
• DOI: 10.1099/ijsem.0.005686

Two -like strains isolated from hot water distribution systems in 2012 have been characterized phenotypically, biochemically and genomically in terms of DNA relatedness. Both strains, HCPI-6 and EUR-108, exhibited biochemical phenotypic profiles typical of species. Cells were Gram-negative motile rods which grew on BCYEα agar but not on blood agar and displayed phenotypic characteristics typical of the family , 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-6 ) and the dominant fatty acids were C  ω7 (28.4 % HCPI-6 , ≈16 % EUR-108), C iso (≈22.5 % and ≈13 %) and C anteiso (19.5 % and ≈23.5 %, respectively). The percent G+C content of genomic DNA was determined to be 39.3 mol %. The 16S rRNA gene, 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 . 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 . 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 sp. nov. is proposed. The type strain is HCPI-6 (=CCUG 75071 =CECT 30569 ).