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Mann Kyoon Shin - One of the best experts on this subject based on the ideXlab platform.
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Segnochrobactrum spirostomi gen. nov., sp. nov., isolated from the ciliate Spirostomum yagiui and description of a novel family, Segnochrobactraceae fam. nov. within the order Rhizobiales of the class Alphaproteobacteria.
International Journal of Systematic and Evolutionary Microbiology, 2020Co-Authors: Sumi Akter, Shahed Uddin Ahmed Shazib, Mann Kyoon ShinAbstract:A bacterial strain, designated Sp-1T, was isolated from the heterotrich ciliate Spirostomum yagiui collected from a reservoir located in Ulsan, Republic of Korea. Cells of Sp-1T were Gram stain-negative, rod-shaped, non-spore-forming, non-motile and contained poly-β-hydroxybutyrate granules. Phylogenetic analyses based on 16S rRNA gene sequences indicated that Sp-1T constituted a distinct phylogenetic lineage within different families in the order Rhizobiales with a pairwise sequence similarity of 95 % to the species of the genus Ochrobactrum: Ochrobactrum anthropi ATCC 49188T and Ochrobactrum cytisi ESC1T (family Brucellaceae ). The major cellular fatty acids were C19 : 0 cyclo ω8c (44.4 %) and C16 : 0 (32.1 %). The identified sole isoprenoid quinone was ubiquinone-10 (Q-10). The major polar lipids produced were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid, two unidentified phospholipids and three unidentified lipids. The genome size was about 5.4 Mbp and the DNA G+C content was 68.2 mol%. Sp-1T exhibited the highest average nucleotide identity value of 76.6 % and in silico DNA–DNA hybridization value of 22.1 % with Pseudoxanthobacter soli DSM 19599T (family Xanthobacteraeae). This strain is distinguishable from closely related members of the order Rhizobiales by its differential phenotypic, chemotaxonomic, genomic and phylogenetic characteristics. On the basis of evidence from polyphasic taxonomic analysis, we concluded that Sp-1T represents a novel species in a novel genus within the order Rhizobiales , for which the name Segnochrobactrum spirostomi gen. nov., sp. nov. is proposed. The type strain is Sp-1T (=KCTC 62036T=JCM 32162T). We also describe a novel family, Segnochrobactraceae fam. nov., to encompass the proposed novel genus and species.
Byung Cheol Cho - One of the best experts on this subject based on the ideXlab platform.
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Cohaesibacter gelatinilyticus gen. nov., sp. nov., a marine bacterium that forms a distinct branch in the order Rhizobiales, and proposal of Cohaesibacteraceae fam. nov.
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, 2008Co-Authors: Chung Yeon Hwang, Byung Cheol ChoAbstract:Two novel Gram-negative bacterial strains, designated CL-GR15T and CL-GR35, were isolated from coastal seawater of the east coast of Korea. Identical 16S rRNA gene sequences were found in the two strains, and it was found that the strains represented a distinct and deep evolutionary lineage of descent in the order Rhizobiales, and clustered with yet-uncultured marine bacteria. This lineage could not be associated with any of 12 known families in the order Rhizobiales. The most closely related established genus was Ochrobactrum (90.7–92.5 % sequence similarity) in the family Brucellaceae. Cells of the strains were facultatively anaerobic, weakly motile rods which occasionally exhibited cohesion with each other. The strains were catalase-, oxidase- and gelatinase-positive, and accumulated intracellular poly-β-hydroxybutyrate granules. Ubiquinone 10 was the major quinone. The major polar lipids comprised phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, an unidentified aminolipid and an unidentified glycolipid. The cellular fatty acids mainly consisted of C18 : 1 ω7c, summed feature 3 (C15 : 0 iso 2-OH and/or C16 : 1 ω7c) and C20 : 1 ω7c. The DNA G+C content was 52.8–53.0 mol%. DNA–DNA hybridization experiments revealed high values (>97 %) for relatedness between strains CL-GR15T and CL-GR35 and suggested that these two strains constituted a single species. The distinct phylogenetic position and combinations of genotypic, phenotypic and chemotaxonomic characteristics support the proposal of Cohaesibacter gen. nov., with the type species Cohaesibacter gelatinilyticus sp. nov. (type strain, CL-GR15T=KCCM 42319T=DSM 18289T). Cohaesibacteraceae fam. nov. is also proposed.
Adrian M Whatmore - One of the best experts on this subject based on the ideXlab platform.
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application of whole genome sequencing and pan family multi locus sequence analysis to characterize relationships within the family Brucellaceae
Frontiers in Microbiology, 2020Co-Authors: Roland Ashford, Jakub Muchowski, Mark S Koylass, Holger C Scholz, Adrian M WhatmoreAbstract:The bacterial family Brucellaceae is currently composed of seven genera, including species of the genus Brucella, a number of which are significant veterinary and zoonotic pathogens. The bacteriological identification of pathogenic Brucella spp. may be hindered by their close phenotypic similarity to other members of the Brucellaceae, particularly of the genus Ochrobactrum. Additionally, a number of novel atypical Brucella taxa have recently been identified, which exhibit greater genetic diversity than observed within the previously described species, and which share genomic features with organisms outside of the genus. Furthermore, previous work has indicated that the genus Ochrobactrum is polyphyletic, raising further questions regarding the relationship between the genus Brucella and wider Brucellaceae. We have applied whole genome sequencing (WGS) and pan-family multi-locus sequence analysis (MLSA) approaches to a comprehensive panel of Brucellaceae type strains, in order to characterize relationships within the family. Phylogenies based on WGS core genome alignments were able to resolve phylogenetic relationships of 31 non-Brucella spp. type strains from within the family, alongside type strains of twelve Brucella species. A phylogeny based on concatenated pan-family MLSA data was largely consistent with WGS based analyses. Notably, recently described atypical Brucella isolates were consistently placed in a single clade with existing species, clearly distinct from all members of the genus Ochrobactrum and wider family. Both WGS and MLSA methods closely grouped Brucella spp. with a sub-set of Ochrobactrum species. However, results also confirmed that the genus Ochrobactrum is polyphyletic, with seven species forming a separate grouping. The pan-family MLSA scheme was subsequently applied to a panel of 50 field strains of the family Brucellaceae, isolated from a wide variety of sources. This analysis confirmed the utility of the pan-Brucellaceae MLSA scheme in placing field isolates in relation to recognized type strains. However, a significant number of these isolates did not cluster with currently identified type strains, suggesting the existence of additional taxonomic diversity within some members of the Brucellaceae. The WGS and pan-family MLSA approaches applied here provide valuable tools for resolving the identity and phylogenetic relationships of isolates from an expanding bacterial family containing a number of important pathogens.
Michel Zygmunt - One of the best experts on this subject based on the ideXlab platform.
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Taxonomic Organization of the Family Brucellaceae Based on a Phylogenomic Approach
Frontiers in Microbiology, 2020Co-Authors: Sébastien Leclercq, Axel Cloeckaert, Michel ZygmuntAbstract:Deciphering the evolutionary history of pathogenic bacteria and their near neighbors may help to understand the genetic or ecological bases which led to their pathogenic behavior. The Brucellaceae family comprises zoonotic pathogenic species belonging to the genus Brucella as well as the environmental genus Ochrobactrum for which some species are considered as opportunistic pathogens. Here, we used a phylogenomic approach including a set of 145 Brucellaceae genomes representative of the family diversity and more than 40 genomes of the order Rhizobiales to infer the taxonomic relationships between the family's species. Our results clarified some unresolved phylogenetic ambiguities, conducting to the exclusion of Mycoplana spp. out of the family Brucellaceae and the positioning of all Brucella spp. as a single genomic species within the current Ochrobactrum species diversity. Additional analyses also revealed that Ochrobactrum spp. separate into two clades, one comprising mostly environmental species while the other one includes the species considered as pathogens (Brucella spp.) or opportunistic pathogens (mainly O. anthropi, O. intermedium, and O. pseudintermedium). Finally, we show that O. intermedium is undergoing a beginning of genome reduction suggestive of an ongoing ecological niche specialization, and that some lineages of O. intermedium and O. anthropi may shift toward an adaption to the human host.
Laurie L. Richardson - One of the best experts on this subject based on the ideXlab platform.
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Aurantimonas coralicida gen. nov., sp. nov., the causative agent of white plague type II on Caribbean scleractinian corals.
International Journal of Systematic and Evolutionary Microbiology, 2003Co-Authors: Ewald B. M. Denner, Garriet W. Smith, Hans-jürgen Busse, Peter Schumann, Thomas Narzt, Shawn W. Polson, Werner Lubitz, Laurie L. RichardsonAbstract:A bacterium previously isolated from a diseased colony of the scleractinian coral Dichocoenia stokesi (common name elliptical star coral) was subjected to a detailed polyphasic taxonomic characterization. The isolate, designated WP1T, was halophilic and strictly aerobic and formed golden-orange-pigmented colonies after prolonged incubation. Cells of WP1T were Gram-negative, rod-shaped and showed a characteristic branching rod morphology. Chemotaxonomically, WP1T was characterized by having Q-10 as the major respiratory lipoquinone and sym-homospermidine as the main component of the cellular polyamine content. The predominant constituent in the cellular fatty acid profile was C18 : 1 ω7c, along with C19 : 0 cyclo ω8c and C16 : 0. Other fatty acids present in smaller amounts were C17 : 0, C18 : 0, C16 : 1 ω7c, C20 : 1 ω7c and C18 : 1 2-OH. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. Minor amounts of diphosphatidylglycerol, phosphatidylmonomethylethanolamine and phosphatidyldimethylethanolamine were present. The G+C content of the genomic DNA was 66·3 mol%. Phylogenetic analysis of the 16S rRNA gene sequence showed that WP1T represents a separate subline of descent within the order ‘Rhizobiales’ of the ‘Alphaproteobacteria’. The new line of descent falls within the group of families that includes the Rhizobiaceae, Bartonellaceae, Brucellaceae and ‘Phyllobacteriaceae’, with no particular relative within this group. The 16S rRNA gene sequence similarity to all established taxa within this group was not higher than 92·0 % (to Mesorhizobium mediterraneum). To accommodate this emerging coral pathogen, the creation of a new genus and species is proposed, Aurantimonas coralicida gen. nov., sp. nov. (type strain WP1T=CIP 107386T =DSM 14790T).
