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1.
Arch Microbiol ; 206(5): 228, 2024 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-38643446

RESUMEN

A novel Lysinibacillus strain, designated KH24T, was isolated from the gut of Siganus fuscescens, a herbivorous fish, which was captured off the coast of Okinawa, Japan. Strain KH24T is a rod-shaped, Gram-stain-positive, spore-forming, and motile bacterium that forms off-white colonies. The 16S rRNA gene sequence of strain KH24T showed the highest similarity (97.4%) with Lysinibacillus pakistanensis JCM 18776T and L. irui IRB4-01T. Genomic similarities between strain KH24T and Lysinibacillus type strains, based on average nucleotide identity, digital DNA-DNA hybridization (genome-to-genome distance calculation), and average amino acid identity were 70.4-77.7%, 17.1-24.4%, and 69.2-81.2%, respectively, which were lower than species delineation thresholds. Strain KH24T growth occurred at pH values of 5.5-8.5, temperatures of 20-40 °C, and NaCl concentrations of 0-4.0%, and optimally at pH 7.0, 30 °C, and 0%, respectively. Unlike related Lysinibacillus type strains, strain KH24T could assimilate D-glucose, D-fructose, N-acetyl-glucosamine, amygdalin, arbutin, esculin, ferric citrate, salicin, D-cellobiose, D-maltose, D-sucrose, and gentiobiose. Major fatty acids included iso-C15:0 (45.8%), anteiso-C15:0 (15.1%), iso-C17:0 (12.6%), and anteiso-C17:0 (10.9%). Menaquinone-7 was the predominant quinone, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and lysophosphatidylethanolamine. Based on its genetic and phenotypic properties, strain KH24T represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillus piscis sp. nov. is proposed. The type strain is KH24T (= JCM 36611 T = KCTC 43676 T).


Asunto(s)
Acetilglucosamina , Amigdalina , Animales , ARN Ribosómico 16S/genética , Aminoácidos , ADN
2.
J Clin Microbiol ; 61(2): e0142522, 2023 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-36533958

RESUMEN

Revisions and new additions to bacterial taxonomy can have a significant widespread impact on clinical practice, infectious disease epidemiology, veterinary microbiology laboratory operations, and wildlife conservation efforts. The expansion of genome sequencing technologies has revolutionized our knowledge of the microbiota of humans, animals, and insects. Here, we address novel taxonomy and nomenclature revisions of veterinary significance that impact bacteria isolated from nondomestic wildlife, with emphasis being placed on bacteria that are associated with disease in their hosts or were isolated from host animal species that are culturally significant, are a target of conservation efforts, or serve as reservoirs for human pathogens.


Asunto(s)
Animales Salvajes , Microbiota , Animales , Humanos , Bacterias
3.
J Clin Microbiol ; 61(2): e0028122, 2023 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-36533907

RESUMEN

Novel bacterial taxonomy and nomenclature revisions can have significant impacts on clinical practice, disease epidemiology, and veterinary microbiology laboratory operations. Expansion of research on the microbiota of humans, animals, and insects has significant potential impacts on the taxonomy of organisms of clinical interest. Implications of taxonomic changes may be especially important when considering zoonotic diseases. Here, we address novel taxonomy and nomenclature revisions of veterinary significance. Noteworthy discussion centers around descriptions of novel mastitis pathogens in Streptococcaceae, Staphylococcaceae, and Actinomycetaceae; bovine reproductive tract pathogens in Corynebacteriaceae; novel members of Mannheimia spp., Leptospira spp., and Mycobacterium spp.; the transfer of Ochrobactrum spp. to Brucella spp.; and revisions to the genus Mycoplasma.


Asunto(s)
Brucella , Leptospira , Femenino , Animales , Bovinos , Humanos , Animales Domésticos , Bacterias , Zoonosis/microbiología
4.
J Clin Microbiol ; 61(1): e0028222, 2023 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-36533910

RESUMEN

A number of factors, including microbiome analyses and the increased utilization of whole-genome sequencing in the clinical microbiology laboratory, has contributed to the explosion of novel prokaryotic species discovery, as well as bacterial taxonomy revision. This review attempts to summarize such changes relative to human clinical specimens that occurred in 2020 and 2021, per primary publication in the International Journal of Systematic and Evolutionary Microbiology or acceptance on Validation Lists published by the International Journal of Systematic and Evolutionary Microbiology. Of particular significance among valid and effectively published taxa within the past 2 years were novel Corynebacterium spp., coagulase-positive staphylococci, Pandoraea spp., and members of family Yersiniaceae. Noteworthy taxonomic revisions include those within the Bacillus and Lactobacillus genera, family Staphylococcaceae (including unifications of subspecies designations to species level taxa), Elizabethkingia spp., and former members of Clostridium spp. and Bacteroides spp. Revisions within the Brucella genus have the potential to cause deleterious effects unless the relevance of such changes is properly communicated by microbiologists to stakeholders in clinical practice, infection prevention, and public health.


Asunto(s)
Bacillus , Staphylococcus , Humanos
5.
Artículo en Inglés | MEDLINE | ID: mdl-37170869

RESUMEN

Two strains of Gram-negative, anaerobic, rod-shaped bacteria, from an abundant but uncharacterized rumen bacterial group of the order 'Christensenellales', were phylogenetically and phenotypically characterized. These strains, designated R-7T and WTE2008T, shared 98.6-99.0 % sequence identity between their 16S rRNA gene sequences. R-7T and WTE2008T clustered together on a distinct branch from other Christensenellaceae strains and had <88.1 % sequence identity to the closest type-strain sequence from Luoshenia tenuis NSJ-44T. The genome sequences of R-7T and WTE2008T had 83.6 % average nucleotide identity to each other, and taxonomic assignment using the Genome Taxonomy Database indicates these are separate species within a novel family of the order 'Christensenellales'. Cells of R-7T and WTE2008T lacked any obvious appendages and their cell wall ultra-structures were characteristic of Gram-negative bacteria. The five most abundant cellular fatty acids of both strains were C16 : 0, C16 : 0 iso, C17 : 0 anteiso, C18 : 0 and C15 : 0 anteiso. The strains used a wide range of the 23 soluble carbon sources tested, and grew best on cellobiose, but not on sugar-alcohols. Xylan and pectin were fermented by both strains, but not cellulose. Acetate, hydrogen, ethanol and lactate were the major fermentation end products. R-7T produced considerably more hydrogen than WTE2008T, which produced more lactate. Based on these analyses, Aristaeellaceae fam. nov. and Aristaeella gen. nov., with type species Aristaeella hokkaidonensis sp. nov., are proposed. Strains R-7T (=DSM 112795T=JCM 34733T) and WTE2008T (=DSM 112788T=JCM 34734T) are the proposed type strains for Aristaeella hokkaidonensis sp. nov. and Aristaeella lactis sp. nov., respectively.


Asunto(s)
Ácidos Grasos , Rumen , Animales , Ácidos Grasos/química , ARN Ribosómico 16S/genética , Filogenia , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Composición de Base , Análisis de Secuencia de ADN , Bacterias Gramnegativas , Hidrógeno
6.
Artículo en Inglés | MEDLINE | ID: mdl-36748507

RESUMEN

A novel bacterial strain, CBA7301T, was isolated from human faeces and was characterised using a polyphasic taxonomic approach. A phylogenetic analysis based on 16S rRNA gene sequences revealed that CBA7301T represented a member of the genus Bacteroides, in the family Bacteroidaceae. The similarity between the 16S rRNA gene sequence of CBA7301T and that of its most closely related species, Bacteroides faecichinchillae JCM 17102T, was 96.2 %, and the average nucleotide identity between these two strains was 77.9 %. The genome size was 6 782 182 bp, and the DNA G+C content was 42.5 mol%. Cells of CBA7301T were Gram-stain-negative, strictly anaerobic and rod-shaped. The optimal growth of this organism occurred at 30-35 °C, pH 7.0 and 0.5 % (w/v) NaCl. The respiratory quinone was menaquinone 10. The predominant polar lipids were phosphatidylethanolamine, phospholipids and aminophospholipids. The major cellular fatty acid was anteiso-C15 : 0. According to the results of the polyphasic taxonomic analysis, CBA7301T represents a novel species of the genus Bacteroides, which we named Bacteroides faecium sp. nov. The type strain is CBA7301T (=KCCM 43355T=ATCC TSD-227T).


Asunto(s)
Ácidos Grasos , Fosfolípidos , Humanos , Ácidos Grasos/química , Análisis de Secuencia de ADN , Filogenia , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Composición de Base , Técnicas de Tipificación Bacteriana , Fosfolípidos/química , Bacteroides , Heces/microbiología
7.
Antonie Van Leeuwenhoek ; 116(2): 109-127, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36244039

RESUMEN

Two facultatively anaerobic, chemoorganoheterotrophic bacterial strains, designated JR1/69-2-13T and JR1/69-3-13T, were isolated from nitrate- and radionuclide-contaminated groundwater (Ozyorsk town, South Urals, Russia). Both strains were found to be motile, Gram-stain negative rod-shaped neutrophilic, psychrotolerant bacteria that grow within the temperature range from 5-10 to 33 °C at 0-3 (0-5)% NaCl (w/v). The major cellular fatty acids were identified as C16:0, C16:1 ω7c, C18:1 ω7c and C17:0 cyclo. The major polar lipids were found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol and unidentified aminophospholipids. The genomic G + C content of strains JR1/69-2-13T and JR1/69-3-13T was determined to be 57.2 and 57.9%, respectively. The 16S rRNA gene sequences of the strains showed high similarity between each other (98.6%) and to members of the genera Pusillimonas (96.8-98.4%) and Candidimonas (97.1-98.0%). The average nucleotide identity and digital DNA-DNA hybridization (dDDH) values among genomes of the new isolates and Pusillimonas and Candidimonas genomes were below 84.5 and 28.8%, respectively, i.e., below the thresholds for species delineation. Based on the phylogenomic, phenotypic and chemotaxonomic characterisation, we propose assignment of strains JR1/69-3-13T (= VKM B-3223T = KCTC 62615T) and JR1/69-2-13T (= VKM B-3222T = KCTC 62614T) to a new genus Pollutimonas as the type strains of two new species, Pollutimonas subterranea gen. nov., sp. nov. and Pollutimonas nitritireducens sp. nov., respectively. As a result of the taxonomic revision of the genus Pusillimonas, three novel genera, Allopusillimonas, Neopusillimonas, and Mesopusillimonas are also proposed; and Candidimonas bauzanensis is reclassified as Pollutimonas bauzanensis comb. nov. Genome analysis of the new isolates suggested molecular mechanisms of their adaptation to an environment highly polluted with nitrate and radionuclides.


Asunto(s)
Nitratos , Fosfolípidos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Ácidos Grasos , Filogenia , Hibridación de Ácido Nucleico , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana
8.
Int J Syst Evol Microbiol ; 72(11)2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36322606

RESUMEN

Five bacterial strains were isolated from symptomatic leaves of Achillea millefolium, Delphinium sp. and Hydrangea sp. in California. Colonies isolated on King's medium B (KMB) appeared white, mucoid and round, similar to Pseudomonas species. Phylogenetic analyses based on 16S rRNA, rpoB, rpoD and gyrB genes placed the bacteria into three distinct groups within Pseudomonas that were most closely related to Pseudomonas viridiflava, Pseudomonas cichorii or Pseudomonas caspiana. To further characterize the strains, phenotypic analyses and the following tests were performed: fatty acid methyl ester composition, LOPAT, fluorescence on KMB, Biolog assay, and transmission electron microscopy. Finally, whole genome sequencing of the strains was conducted, and the sequences were compared with reference genomes of Pseudomonas species based on average nucleotide identity (ANI). The first group, which consists of three strains isolated from delphinium, hydrangea and achillea, had 95.6-96.9 % pairwise ANI between each other; the second group consists of two strains isolated from delphinium that had 100 % pairwise ANI. Although comparisons of the two groups with publicly available genomes revealed closest relationships with P. viridiflava (91.6 %), P. caspiana (88.3 %) and P. asturiensis (86.7 %), ANI values were less than 95 % compared to all validly published pseudomonads. Combining genomic and phenotypic data, we conclude that these strains represent two new species and the names proposed are Pseudomonas quasicaspiana sp. nov. (type strain DSMZ 11 30 42T=LMG 32 434T) for the strains isolated from delphinium, achillea and hydrangea and Pseudomonas californiensis sp. nov. (DSMZ 11 30 43T=LMG 32 432T) for the two strains isolated from delphinium. The specific epithets quasicaspiana and californiensis were selected based on the close phylogenetic relationship of strains with P. caspiana and on the geographic location of isolation, respectively.


Asunto(s)
Ácidos Grasos , Pseudomonas , ARN Ribosómico 16S/genética , Filogenia , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Análisis de Secuencia de ADN , Composición de Base , Hibridación de Ácido Nucleico , Ácidos Grasos/química
9.
Antonie Van Leeuwenhoek ; 115(4): 497-503, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35149918

RESUMEN

A Gram-stain negative, aerobic, rod-shaped bacterium, designated 126T, was isolated from the intestinal content of a sea cucumber, Apostichopus japonicus, in China. Strain 126T was found to grow optimally at 25-28 °C and pH 7.5-8.0 in marine 2216 E medium, with tolerance of 1-7% (w/v) NaCl. Strain 126T is motile by means of one to several polar flagella. The dominant fatty acids of strain 126T were identified as C16:1 ω7c/C16:1 ω6c (29.5%), C18:1 ω7c/C18:1 ω6c (19.8%) and C16:0 (16.7%). The respiratory quinone was found to be Q-8. The polar lipid profile was found to be mainly composed of phosphatidylglycerol and phosphatidylethanolamine. The total length of the draft genome is approximately 4.2 × 106 bp, encoding 3655 genes and 3576 coding sequences. The G + C content of the genomic DNA is 48.0%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 126T belongs to the genus Neiella and is closely related to Neiella marina J221T (96.5%). Genomic comparisons of 126T to N. marina J221T revealed that they had similar genome size, G + C content and complement of clusters of orthologous groups. However, average nucleotide identity and digital DNA-DNA hybridization values between strains126T and N. marina J221T was 75.5% and 19.7%, which could distinguish the strains. On the basis of these phenotypic and genotypic data, strain 126T is concluded to represent a novel species, for which the name Neiella holothuriorum sp. nov. is proposed. The type strain is 126T (= GDMCC 1.2530T = KCTC 82829T).


Asunto(s)
Pepinos de Mar , Stichopus , Animales , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/análisis , Hibridación de Ácido Nucleico , Fosfolípidos/análisis , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Stichopus/genética , Stichopus/microbiología
10.
Phytopathology ; 112(8): 1630-1639, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35196068

RESUMEN

Xanthomonas arboricola comprises a number of economically important fruit tree pathogens classified within different pathovars. Dozens of nonpathogenic and taxonomically unvalidated strains are also designated as X. arboricola, leading to a complicated taxonomic status in the species. In this study, we have evaluated the whole-genome resources of all available Xanthomonas spp. strains designated as X. arboricola in the public databases to refine the members of the species based on DNA similarity indexes and core genome-based phylogeny. Our results show that, of the nine validly described pathovars within X. arboricola, pathotype strains of seven pathovars are taxonomically genuine, belonging to the core clade of the species regardless of their pathogenicity on the host of isolation (thus the validity of pathovar status). However, strains of X. arboricola pv. guizotiae and X. arboricola pv. populi do not belong to X. arboricola because of the low DNA similarities between the type strain of the species and the pathotype strains of these two pathovars. Thus, we propose to elevate the two pathovars to the rank of a species as X. guizotiae sp. nov. with the type strain CFBP 7408T and X. populina sp. nov. with the type strain CFBP 3123T. In addition, other mislabeled strains of X. arboricola were scattered within Xanthomonas spp. that belong to previously described species or represent novel species that await formal description.


Asunto(s)
Enfermedades de las Plantas , Xanthomonas , Frutas , Filogenia
11.
Artículo en Inglés | MEDLINE | ID: mdl-33406029

RESUMEN

The genus Escherichia comprises five species and at least five lineages currently not assigned to any species, termed 'Escherichia cryptic clades'. We isolated an Escherichia strain from an international traveller and resolved the complete DNA sequence of the chromosome and an IncI multidrug resistance plasmid using Illumina and Nanopore whole-genome sequencing (WGS). Strain OPT1704T can be differentiated from existing Escherichia species using biochemical (VITEK2) and genomic tests [average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH)]. Phylogenetic analysis based on alignment of 16S rRNA sequences and 682 concatenated core genes showed similar results. Our analysis further revealed that strain OPT1704T falls within Escherichia cryptic clade IV and is closely related to cryptic clade III. Combining our analyses with publicly available WGS data of cryptic clades III and IV from Enterobase confirmed the close relationship between clades III and IV (>96 % interclade ANI), warranting assignment of both clades to the same novel species. We propose Escherichia ruysiae sp. nov. as a novel species, encompassing Escherichia cryptic clades III and IV (type strain OPT1704T=NCCB 100732T=NCTC 14359T).


Asunto(s)
Escherichia/clasificación , Heces/microbiología , Filogenia , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Escherichia/aislamiento & purificación , Genes Bacterianos , Humanos , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Viaje
12.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34846285

RESUMEN

Chemotaxonomic methods played an important role in the development of the polyphasic approach to classification of Archaea and Bacteria. However, we here argue that routine application of these methods is unnecessary in an era when genomic data are available and sufficient for species delineation. Thus, authors who choose not to utilize such methods should not be forced to do so during the peer review and editorial handling of manuscripts describing novel species. Instead, we argue that chemotaxonomy will thrive if improved analytical methods are introduced and deployed, primarily by specialist laboratories, in studies at taxonomic levels above the characterisation of novel species.


Asunto(s)
Bacterias/clasificación , Filogenia , Terminología como Asunto
13.
Int J Mol Sci ; 22(10)2021 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-34069990

RESUMEN

The taxonomic composition of microbial communities can be assessed using universal marker amplicon sequencing. The most common taxonomic markers are the 16S rDNA for bacterial communities and the internal transcribed spacer (ITS) region for fungal communities, but various other markers are used for barcoding eukaryotes. A crucial step in the bioinformatic analysis of amplicon sequences is the identification of representative sequences. This can be achieved using a clustering approach or by denoising raw sequencing reads. DADA2 is a widely adopted algorithm, released as an R library, that denoises marker-specific amplicons from next-generation sequencing and produces a set of representative sequences referred to as 'Amplicon Sequence Variants' (ASV). Here, we present Dadaist2, a modular pipeline, providing a complete suite for the analysis that ranges from raw sequencing reads to the statistics of numerical ecology. Dadaist2 implements a new approach that is specifically optimised for amplicons with variable lengths, such as the fungal ITS. The pipeline focuses on streamlining the data flow from the command line to R, with multiple options for statistical analysis and plotting, both interactive and automatic.


Asunto(s)
Código de Barras del ADN Taxonómico/estadística & datos numéricos , Metagenómica/estadística & datos numéricos , Microbiota/genética , Programas Informáticos , Algoritmos , Análisis por Conglomerados , Biología Computacional/métodos , Interpretación Estadística de Datos , Secuenciación de Nucleótidos de Alto Rendimiento , Metadatos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
14.
Appl Environ Microbiol ; 86(6)2020 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-31924620

RESUMEN

Members of the genus Clavibacter are economically important bacterial plant pathogens infecting a set of diverse agricultural crops (e.g., alfalfa, corn, potato, tomato, and wheat). Tomato-associated Clavibacter sp. strains account for a great portion of the genetic diversity of the genus, and C. michiganensissensu stricto (formerly C. michiganensis subsp. michiganensis), causing bacterial canker disease, is considered one of the most destructive seed-borne agents for the crop worldwide. However, current taxonomic descriptions of the genus do not reflect the existing diversity of the strains, resulting in unsatisfactory results in quarantine surveys for the pathogens. In this study, we used all the available genome sequences of Clavibacter sp. strains, including the type strains of newly described subspecies, to provide precise insight into the diversity of tomato-associated members of the genus and further clarify the taxonomic status of the strains using genotypic and phenotypic features. The results of phylogenetic analyses revealed the existence of nine hypothetical new species among the investigated strains. None of the three new subspecies (i.e., C. michiganensis subsp. californiensis, C. michiganensis subsp. chilensis, and C. michiganensis subsp. phaseoli) is included within the tomato-pathogenic C. michiganensissensu stricto lineage. Although comparative genomics revealed the lack of chp and tomA pathogenicity determinant gene clusters in the nonpathogenic strains, a number of pathogenicity-related genes were noted to be present in all the strains regardless of their pathogenicity characteristics. Altogether, our results indicate a need for a formal taxonomic reconsideration of tomato-associated Clavibacter sp. strains to facilitate differentiation of the lineages in quarantine inspections.IMPORTANCEClavibacter spp. are economically important bacterial plant pathogens infecting a set of diverse agricultural crops, such as alfalfa, corn, pepper, potato, tomato, and wheat. A number of plant-pathogenic members of the genus (e.g., C. michiganensissensu stricto and C. sepedonicus, infecting tomato and potato plants, respectively) are included in the A2 (high-risk) list of quarantine pathogens by the European and Mediterranean Plant Protection Organization (EPPO). Although tomato-associated members of Clavibacter spp. account for a significant portion of the genetic diversity in the genus, only the strains belonging to C. michiganensissensu stricto (formerly C. michiganensis subsp. michiganensis) cause bacterial canker disease of tomato and are subjected to the quarantine inspections. Hence, discrimination between the pathogenic and nonpathogenic Clavibacter sp. strains associated with tomato seeds and transplants plays a pivotal role in the accurate detection and cost-efficient management of the disease. On the other hand, detailed information on the genetic contents of different lineages of the genus would lead to the development of genome-informed specific detection techniques. In this study, we have provided an overview of the phylogenetic and genomic differences between the pathogenic and nonpathogenic tomato-associated Clavibacter sp. strains. We also noted that the taxonomic status of newly introduced subspecies of C. michiganensis (i.e., C. michiganensis subsp. californiensis, C. michiganensis subsp. chilensis, and C. michiganensis subsp. phaseoli) should be reconsidered.


Asunto(s)
Actinobacteria/clasificación , Variación Genética , Genoma Bacteriano , Interacciones Huésped-Patógeno , Filogenia , Solanum lycopersicum/microbiología , Actinobacteria/genética , Genómica
15.
Int J Syst Evol Microbiol ; 70(4): 2925-2936, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32100698

RESUMEN

Although described bacterial species increased in the twenty-first century, they correspond to a tiny fraction of the actual number of species living on our planet. The volume of textual data of these descriptions constitutes valuable information for revealing trends that in turn could support strategies for improvement of bacterial taxonomy. In this study, a text mining approach was used to generate bibliometric data to verify the state-of-art of bacterial taxonomy. Around 9700 abstracts of bacterial classification containing the expression 'sp. nov.' and published between 2001 and 2018 were downloaded from PubMed and analysed. Most articles were from PR China and the Republic of Korea, and published in the International Journal of Systematic and Evolutionary Microbiology. From about 10 800 species names detected, 93.33 % were considered valid according to the rules of the Bacterial Code, and they corresponded to 82.98 % of the total number of species validated between 2001 and 2018. Streptomyces, Bacillus and Paenibacillus each had more than 200 species described in the period. However, almost 40 % of all species were from the phylum Proteobacteria. Most bacteria were Gram-stain-negative, bacilli and isolated from soil. Thirteen species and one genus homonyms were found. With respect to methodologies of bacterial characterization, the use of terms related to 16S rRNA and polar lipids increased along these years, and terms related to genome metrics only began to appear from 2009 onward, although at a relatively lower frequency. Bacterial taxonomy is known as a conservative discipline, but it gradually changed in terms of players and practices. With the advent of the mandatory use of genomic analyses for species description, we are probably witnessing a turning point in the evolution of bacterial taxonomy.


Asunto(s)
Bacterias/clasificación , Minería de Datos , Terminología como Asunto , China , ADN Bacteriano/genética , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , República de Corea , Microbiología del Suelo
16.
Int J Syst Evol Microbiol ; 70(11): 5969-5971, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32945765

RESUMEN

Based on the high phylogenetic relatedness of Auricoccus indicus Prakash et al. 2017 and Abyssicoccus albus Jiang et al. 2016, it is proposed to unite them with retaining the latter name as having nomenclatural priority. As the result of the species unification, the genus Auricoccus name is proposed to consider as illegitimate in the boundaries determined by Rule 51a of the International Code of Nomenclature of Prokaryotes.


Asunto(s)
Staphylococcaceae/clasificación , Filogenia , Terminología como Asunto
17.
Genome ; 62(2): 45-52, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30649978

RESUMEN

Bacterial populations are routinely characterized based on microscopic examination, colony formation, and biochemical tests. However, in the recent past, bacterial identification, classification, and nomenclature have been strongly influenced by genome sequence information. Advances in bioinformatics and growth in genome databases has placed genome-based metadata analysis in the hands of researchers who will require taxonomic experience to resolve intricacies. To achieve this, different tools are now available to quantitatively measure genome relatedness within members of the same species, and genome-wide average nucleotide identity (gANI) is one such reliable tool to measure genome similarity. A genome assembly with a gANI score of <95% at the intraspecies level is generally considered indicative of a separate species. In this study, we have analysed 300 whole-genome sequences belonging to 26 different bacterial species available in the NCBI Genome database and calculated their similarity at the intraspecies level based on gANI score. At the intraspecies level, nine bacterial species showed less than 90% gANI and more than 10% of unaligned regions. We suggest the appropriate use of available bioinformatics resources after genome assembly to arrive at the proper bacterial identification, classification, and nomenclature to avoid erroneous species assignments and disparity due to diversity at the intraspecies level.


Asunto(s)
Código de Barras del ADN Taxonómico/métodos , Genoma Bacteriano , Filogenia , Bacterias/clasificación , Bacterias/genética
18.
Int J Syst Evol Microbiol ; 69(7): 2057-2063, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31091185

RESUMEN

In the last 4 years, most of the species previously classified as members of the genus Burkholderia have been transferred to the novel genera Paraburkholderia, Caballeronia, Robbsia, Mycetohabitans and Trinickia. However, there have been objections to splitting the genus Burkholderiasensu lato, and based on this taxonomic opinion, strain RPE64T, which has the 16S rRNA gene sequence identical to that of Caballeronia peredens LMG 29314T, has recently been proposed as the type strain of Burkholderia insecticolasp. nov. The arguments against the split were analysed in this study and found to be not convincing enough to revise the taxonomic positions of members of the novel genera. Therefore, based on the results of phylogenetic analyses, including comparisons of 16S rRNA gene sequences and those of concatenated proteins, as well as on the fact that strain RPE64T had all molecular signatures included as Caballeronia-specific markers in the genus description, we propose to reclassify B. insecticola as Caballeronia insecticola comb. nov. The results of this study also showed that 'Burkholderia novacaledonica' and 'Burkholderia ultramafica' should be transferred to the genera Caballeronia and Paraburkholderia, respectively.


Asunto(s)
Burkholderia/clasificación , Burkholderiaceae/clasificación , Filogenia , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Mutación INDEL , ARN Ribosómico 16S/genética , Reproducibilidad de los Resultados , Análisis de Secuencia de ADN
20.
Int J Syst Evol Microbiol ; 68(5): 1565-1570, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29537359

RESUMEN

A bacterial strain, designated IMCC25901T, was isolated from a freshwater lake, Soyang, in the Republic of Korea. The strain was Gram-stain-negative, aerobic, non-motile, orange-coloured and short rod-shaped. The 16S rRNA gene sequence analysis showed that strain IMCC25901T was most closely related to Flavobacterium yonginense HMD1001T (97.0 %) and formed a robust phylogenetic clade with other species of the genus Flavobacterium. Growth of strain IMCC25901T was observed at 10-30 °C (optimum, 20 °C), pH 6-8 (optimum, pH 7) and 0-1.0 % NaCl (optimum, 0 %). The DNA G+C content of strain IMCC25901T was 34.2 mol%. The major fatty acid constituents of the strain were anteiso-C15 : 0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and iso-C15 : 0. Cells of strain IMCC25901T contained phosphatidylethanolamine, an unidentified phospholipid, two unidentified aminolipids and two unidentified lipids. The isoprenoid quinone detected in the strain was MK-6. On the basis of the taxonomic data obtained in this study, it was concluded that strain IMCC25901T represented a novel species in the genus Flavobacterium, for which the name Flavobacterium lacicola sp. nov. is proposed. The type strain of Flavobacterium lacicola is IMCC25901T (=KCTC 52571T=NBRC 112883T).


Asunto(s)
Flavobacterium/clasificación , Lagos/microbiología , Filogenia , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Flavobacterium/genética , Flavobacterium/aislamiento & purificación , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
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