Phylogenomic Study of Burkholderia glathei-like Organisms, Proposal of 13 Novel Burkholderia Species and Emended Descriptions of Burkholderia sordidicola, Burkholderia zhejiangensis, and Burkholderia grimmiae

Partial gyrB gene sequence analysis of 17 isolates from human and environmental sources revealed 13 clusters of strains and identified them as Burkholderia glathei clade (BGC) bacteria. The taxonomic status of these clusters was examined by whole-genome sequence analysis, determination of the G+C content, whole-cell fatty acid analysis and biochemical characterization. The whole-genome sequence-based phylogeny was assessed using the Genome Blast Distance Phylogeny (GBDP) method and an extended multilocus sequence analysis (MLSA) approach. The results demonstrated that these 17 BGC isolates represented 13 novel Burkholderia species that could be distinguished by both genotypic and phenotypic characteristics. BGC strains exhibited a broad metabolic versatility and developed beneficial, symbiotic, and pathogenic interactions with different hosts. Our data also confirmed that there is no phylogenetic subdivision in the genus Burkholderia that distinguishes beneficial from pathogenic strains. We therefore propose to formally classify the 13 novel BGC Burkholderia species as Burkholderia arvi sp. nov. (type strain LMG 29317(T) = CCUG 68412(T)), Burkholderia hypogeia sp. nov. (type strain LMG 29322(T) = CCUG 68407(T)), Burkholderia ptereochthonis sp. nov. (type strain LMG 29326(T) = CCUG 68403(T)), Burkholderia glebae sp. nov. (type strain LMG 29325(T) = CCUG 68404(T)), Burkholderia pedi sp. nov. (type strain LMG 29323(T) = CCUG 68406(T)), Burkholderia arationis sp. nov. (type strain LMG 29324(T) = CCUG 68405(T)), Burkholderia fortuita sp. nov. (type strain LMG 29320(T) = CCUG 68409(T)), Burkholderia temeraria sp. nov. (type strain LMG 29319(T) = CCUG 68410(T)), Burkholderia calidae sp. nov. (type strain LMG 29321(T) = CCUG 68408(T)), Burkholderia concitans sp. nov. (type strain LMG 29315(T) = CCUG 68414(T)), Burkholderia turbans sp. nov. (type strain LMG 29316(T) = CCUG 68413(T)), Burkholderia catudaia sp. nov. (type strain LMG 29318(T) = CCUG 68411(T)) and Burkholderia peredens sp. nov. (type strain LMG 29314(T) = CCUG 68415(T)). Furthermore, we present emended descriptions of the species Burkholderia sordidicola, Burkholderia zhejiangensis and Burkholderia grimmiae. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA and gyrB gene sequences determined in this study are LT158612-LT158624 and LT158625-LT158641, respectively.