scholarly journals Assessment of phylo-functional coherence along the bacterial phylogeny and taxonomy

2019 ◽  
Author(s):  
Marcos Parras-Moltó ◽  
Daniel Aguirre de Cárcer
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Content ◽  
Rrna Gene ◽  
Bacterial Taxonomy ◽  
Taxonomic Rank ◽  
Bacterial Phyla ◽  
Bacterial Phylogeny ◽  
Content Similarity ◽  
Functional Coherence

ABSTRACTIn this report we use available curated phylogenies, taxonomy, and genome annotations to assess the phylogenetic and gene content similarity associated with each different taxa and taxonomic rank. Subsequently, we employ the same data to delimit the frontiers of functional coherence along the bacterial phylogeny. Our results show that within-group phylogenetic and gene content similarity of taxa in the same rank are not homogenous, and that these values show extensive overlap between ranks. Functional coherence along the 16S rRNA gene-based phylogeny was limited to 44 particular nodes presenting large variations in phylogenetic depth. For instance, the deep subtree affiliated to class Actinobacteria presented functional coherence, while the shallower family Enterobacteriaceae-affiliated subtree did not. On the other hand, functional coherence along the genome-based phylogeny delimited deep subtrees affiliated to phyla Actinobacteriota, Deinococcota, Chloroflexota, Firmicutes, and a subtree containing the rest of the bacterial phyla.IMPORTANCEWhile bacterial taxonomy and phylogeny resources as well as related bioinformatic tools continue to improve, the question remains as to how they should best be employed in studies using 16S rRNA gene surveys to assess bacteria-ecosystem relationships, a widespread approach. The results contained herein lead to the recommendation that all ranks from genus to class/phylum be employed if using taxonomic binning in the analysis of 16S rRNA gene surveys. With regards to the use of phylogeny or clustering-based approaches, single or arbitrary tree topology or sequence distance thresholds should not be employed. Instead, the results presented here can be used to obtain more meaningful results in many microbial ecology and evolution research scenarios. Moreover, we provide dedicated scripts and files that can be used to continue the exploration of functional coherence along the bacterial phylogeny employing different parameters or input data.

scholarly journals Assessment of phylo-functional coherence along the bacterial phylogeny and taxonomy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcos Parras-Moltó ◽  
Daniel Aguirre de Cárcer
Keyword(s):  
Input Data ◽  
Gene Content ◽  
Rrna Gene ◽  
Taxonomic Rank ◽  
Bacterial Phyla ◽  
Bacterial Phylogeny ◽  
Genome Annotations ◽  
Content Similarity ◽  
The 16S Rrna Gene ◽  
Functional Coherence

AbstractIn this report we use available curated phylogenies, taxonomy, and genome annotations to assess the phylogenetic and gene content similarity associated with each different taxon and taxonomic rank. Subsequently, we employ the same data to assess the frontiers of functional coherence along the bacterial phylogeny. Our results show that within-group phylogenetic and gene content similarity of taxa in the same rank are not homogenous, and that these values show extensive overlap between ranks. Functional coherence along the 16S rRNA gene-based phylogeny was limited to 44 particular nodes presenting large variations in phylogenetic depth. For instance, the deep subtree affiliated to class Actinobacteria presented functional coherence, while the shallower family Enterobacteriaceae-affiliated subtree did not. On the other hand, functional coherence along the genome-based phylogeny delimited deep subtrees affiliated to phyla Actinobacteriota, Deinococcota, Chloroflexota, Firmicutes, and a subtree containing the rest of the bacterial phyla. The results presented here can be used to guide the exploration of results in many microbial ecology and evolution research scenarios. Moreover, we provide dedicated scripts and files that can be used to continue the exploration of functional coherence along the bacterial phylogeny employing different parameters or input data (https://git.io/Jec5U).

scholarly journals A method for high precision sequencing of near full-length 16S rRNA genes on an Illumina MiSeq

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2492 ◽  
Author(s):  
Catherine M. Burke ◽  
Aaron E. Darling
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
High Throughput ◽  
Single Molecule ◽  
Illumina Miseq ◽  
Full Length ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Bacterial Taxonomy

BackgroundThe bacterial 16S rRNA gene has historically been used in defining bacterial taxonomy and phylogeny. However, there are currently no high-throughput methods to sequence full-length 16S rRNA genes present in a sample with precision.ResultsWe describe a method for sequencing near full-length 16S rRNA gene amplicons using the high throughput Illumina MiSeq platform and test it using DNA from human skin swab samples. Proof of principle of the approach is demonstrated, with the generation of 1,604 sequences greater than 1,300 nt from a single Nano MiSeq run, with accuracy estimated to be 100-fold higher than standard Illumina reads. The reads were chimera filtered using information from a single molecule dual tagging scheme that boosts the signal available for chimera detection.ConclusionsThis method could be scaled up to generate many thousands of sequences per MiSeq run and could be applied to other sequencing platforms. This has great potential for populating databases with high quality, near full-length 16S rRNA gene sequences from under-represented taxa and environments and facilitates analyses of microbial communities at higher resolution.

scholarly journals Wild specimens of sand fly phlebotomine Lutzomyia evansi, vector of leishmaniasis, show high abundance of Methylobacterium and natural carriage of Wolbachia and Cardinium types in the midgut microbiome

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rafael J. Vivero ◽  
Marcela Villegas-Plazas ◽  
Gloria E. Cadavid-Restrepo ◽  
Claudia Ximena Moreno Herrera ◽  
Sandra I. Uribe ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
High Throughput Sequencing ◽  
Sand Fly ◽  
Human Populations ◽  
Rrna Gene ◽  
Remarkable Feature ◽  
Core Microbiome ◽  
Bacterial Phyla ◽  
Wide Range

AbstractPhlebotomine sand flies are remarkable vectors of several etiologic agents (virus, bacterial, trypanosomatid Leishmania), posing a heavy health burden for human populations mainly located at developing countries. Their intestinal microbiota is involved in a wide range of biological and physiological processes, and could exclude or facilitate such transmission of pathogens. In this study, we investigated the Eubacterial microbiome from digestive tracts of Lu. evansi adults structure using 16S rRNA gene sequence amplicon high throughput sequencing (Illumina MiSeq) obtained from digestive tracts of Lu. evansi adults. The samples were collected at two locations with high incidence of the disease in humans: peri-urban and forest ecosystems from the department of Sucre, Colombia. 289,068 quality-filtered reads of V4 region of 16S rRNA gene were obtained and clustered into 1,762 operational taxonomic units (OTUs) with 97% similarity. Regarding eubacterial diversity, 14 bacterial phyla and 2 new candidate phyla were found to be consistently associated with the gut microbiome content. Proteobacteria, Firmicutes, and Bacteroidetes were the most abundant phyla in all the samples and the core microbiome was particularly dominated by Methylobacterium genus. Methylobacterium species, are known to have mutualistic relationships with some plants and are involved in shaping the microbial community in the phyllosphere. As a remarkable feature, OTUs classified as Wolbachia spp. were found abundant on peri-urban ecosystem samples, in adult male (OTUs n = 776) and unfed female (OTUs n = 324). Furthermore, our results provide evidence of OTUs classified as Cardinium endosymbiont in relative abundance, notably higher with respect to Wolbachia. The variation in insect gut microbiota may be determined by the environment as also for the type of feeding. Our findings increase the richness of the microbiota associated with Lu. evansi. In this study, OTUs of Methylobacterium found in Lu. evansi was higher in engorged females, suggesting that there are interactions between microbes from plant sources, blood nutrients and the parasites they transmit during the blood intake.

scholarly journals Discovery of the Novel Candidate Phylum “Poribacteria” in Marine Sponges

2004 ◽  
Vol 70 (6) ◽  
pp. 3724-3732 ◽  
Author(s):  
Lars Fieseler ◽  
Matthias Horn ◽  
Michael Wagner ◽  
Ute Hentschel
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Sequence Similarity ◽  
Marine Sponges ◽  
Rrna Gene ◽  
The Novel ◽  
Electron Microscopic ◽  
Pcr Screening ◽  
Bacterial Phyla ◽  
Cell Compartmentalization

ABSTRACT Marine sponges (Porifera) harbor large amounts of commensal microbial communities within the sponge mesohyl. We employed 16S rRNA gene library construction using specific PCR primers to provide insights into the phylogenetic identity of an abundant sponge-associated bacterium that is morphologically characterized by the presence of a membrane-bound nucleoid. In this study, we report the presence of a previously unrecognized evolutionary lineage branching deeply in the domain Bacteria that is moderately related to the Planctomycetes, Verrucomicrobia, and Chlamydia lines of decent. Because members of this lineage showed <75% 16S rRNA gene sequence similarity to known bacterial phyla, we suggest the status of a new candidate phylum, named “Poribacteria”, to acknowledge the affiliation of the new bacterium with sponges. The affiliation of the morphologically conspicuous sponge bacterium with the novel phylogenetic lineage was confirmed by fluorescence in situ hybridization with newly designed probes targeting different sites of the poribacterial 16S rRNA. Consistent with electron microscopic observations of cell compartmentalization, the fluorescence signals appeared in a ring-shaped manner. PCR screening with “Poribacteria”-specific primers gave positive results for several other sponge species, while samples taken from the environment (seawater, sediments, and a filter-feeding tunicate) were PCR negative. In addition to a report for Planctomycetes, this is the second report of cell compartmentalization, a feature that was considered exclusive to the eukaryotic domain, in prokaryotes.

scholarly journals Cautionary tale of using 16S rRNA gene sequence similarity values in identification of human-associated bacterial species

2015 ◽  
Vol 65 (Pt_6) ◽  
pp. 1929-1934 ◽  
Author(s):  
Morgane Rossi-Tamisier ◽  
Samia Benamar ◽  
Didier Raoult ◽  
Pierre-Edouard Fournier
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
Sequence Similarity ◽  
Bacterial Species ◽  
16S Rrna Gene Sequence ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Bacterial Taxonomy ◽  
Associated Species

Modern bacterial taxonomy is based on a polyphasic approach that combines phenotypic and genotypic characteristics, including 16S rRNA sequence similarity. However, the 95 % (for genus) and 98.7 % (for species) sequence similarity thresholds that are currently recommended to classify bacterial isolates were defined by comparison of a limited number of bacterial species, and may not apply to many genera that contain human-associated species. For each of 158 bacterial genera containing human-associated species, we computed pairwise sequence similarities between all species that have names with standing in nomenclature and then analysed the results, considering as abnormal any similarity value lower than 95 % or greater than 98.7 %. Many of the current bacterial species with validly published names do not respect the 95 and 98.7 % thresholds, with 57.1 % of species exhibiting 16S rRNA gene sequence similarity rates ≥98.7 %, and 60.1 % of genera containing species exhibiting a 16S rRNA gene sequence similarity rate <95 %. In only 17 of the 158 genera studied (10.8 %), all species respected the 95 and 98.7 % thresholds. As we need powerful and reliable taxonomical tools, and as potential new tools such as pan-genomics have not yet been fully evaluated for taxonomic purposes, we propose to use as thresholds, genus by genus, the minimum and maximum similarity values observed among species.

scholarly journals Phylogenetic Analysis and In Situ Identification of Bacteria Community Composition in an Acidic Sphagnum Peat Bog

2006 ◽  
Vol 72 (3) ◽  
pp. 2110-2117 ◽  
Author(s):  
Svetlana N. Dedysh ◽  
Timofei A. Pankratov ◽  
Svetlana E. Belova ◽  
Irina S. Kulichevskaya ◽  
Werner Liesack
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Community Composition ◽  
Significant Proportion ◽  
Peat Bog ◽  
Rrna Gene ◽  
Bacterial Phyla ◽  
Cell Counts ◽  
Novel Strategy

ABSTRACT The Bacteria community composition in an acidic Sphagnum peat bog (pH 3.9 to 4.5) was characterized by a combination of 16S rRNA gene clone library analysis, rRNA-targeted fluorescence in situ hybridization (FISH), and cultivation. Among 84 environmental 16S rRNA gene clones, a set of only 16 cloned sequences was closely related (≥95% similarity) to taxonomically described organisms. Main groups of clones were affiliated with the Acidobacteria (24 clones), Alphaproteobacteria (20), Verrucomicrobia (13), Actinobacteria (8), Deltaproteobacteria (4), Chloroflexi (3), and Planctomycetes (3). The proportion of cells that hybridized with oligonucleotide probes specific for members of the domains Bacteria (EUB338-mix) and Archaea (ARCH915 and ARC344) accounted for only 12 to 22% of the total cell counts. Up to 24% of the EUB338-positive cells could be assigned by FISH to specific bacterial phyla. Alphaproteobacteria and Planctomycetes were the most numerous bacterial groups (up to 1.3 × 107 and 1.1 × 107 cells g−1 peat, respectively). In contrast to conventional plating techniques, a novel biofilm-mediated enrichment approach allowed us to isolate some representatives of predominant Bacteria groups, such as Acidobacteria and Planctomycetes. This novel strategy has great potential to enable the isolation of a significant proportion of the peat bog bacterial diversity.

Oceanobacillus indicireducens sp. nov., a facultative alkaliphile that reduces an indigo dye

2013 ◽  
Vol 63 (Pt_4) ◽  
pp. 1437-1442 ◽  
Author(s):  
Kikue Hirota ◽  
Kenichi Aino ◽  
Yoshinobu Nodasaka ◽  
Isao Yumoto
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Type Species ◽  
Phylogenetic Analyses ◽  
Tween 20 ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
Content Similarity

An indigo-reducing facultatively alkaliphilic and halophilic strain, designated strain A21T, was isolated from a fermented Polygonum indigo (Polygonum tinctorium Lour.) liquor sample aged for 4 days prepared in a laboratory. 16S rRNA gene sequence phylogeny suggested that strain A21T was a member of the genus Oceanobacillus with the closest relative being the type strain of Oceanobacillus chironomi (similarity: 96.0 %). The cells of the isolate stained Gram-positive and were facultatively anaerobic straight rods that were motile by peritrichous flagella. The strain grew between 18 and 48 °C with optimum growth at 39 °C. It grew in the pH range of 7–12. It hydrolysed casein, gelatin and Tween 20 but not Tweens 40, 60 and 80, starch or DNA. No isoprenoid quinone was detected and the DNA G+C content was 39.7 mol%. The whole-cell fatty acid profile mainly consisted of iso-C15 : 0, anteiso-C15 : 0 and C16 : 0. DNA–DNA hybridization experiments with O. chironomi revealed 13 % relatedness. Owing to the differences in phenotypic and chemotaxonomic characteristics, and phylogenetic analyses based on 16S rRNA gene sequences and DNA–DNA relatedness data from reported Oceanobacillus species, the isolate merits classification as a representative of a novel species, for which the name Oceanobacillus indicireducens sp. nov. is proposed. The type strain is A21T ( = JCM 17251T  = NCIMB 14685T). The description of the genus Oceanobacillus is also emended.

scholarly journals Advantage of Using Inosine at the 3′ Termini of 16S rRNA Gene Universal Primers for the Study of Microbial Diversity

2006 ◽  
Vol 72 (11) ◽  
pp. 6902-6906 ◽  
Author(s):  
Eitan Ben-Dov ◽  
Orr H. Shapiro ◽  
Nachshon Siboni ◽  
Ariel Kushmaro
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Microbial Diversity ◽  
Microbial Communities ◽  
Environmental Samples ◽  
Annealing Temperature ◽  
Universal Primers ◽  
Rrna Gene ◽  
Bacterial Phyla ◽  
Primer Sets

ABSTRACT To overcome the shortcomings of universal 16S rRNA gene primers 8F and 907R when studying the diversity of complex microbial communities, the 3′ termini of both primers were replaced with inosine. A comparison of the clone libraries derived using both primer sets showed seven bacterial phyla amplified by the altered primer set (8F-I/907R-I) whereas the original set amplified sequences belonging almost exclusively to Proteobacteria (95.8%). Sequences belonging to Firmicutes (42.6%) and Thermotogae (9.3%) were more abundant in a library obtained by using 8F-I/907R-I at a PCR annealing temperature of 54°C, while Proteobacteria sequences were more frequent (62.7%) in a library obtained at 50°C, somewhat resembling the result obtained using the original primer set. The increased diversity revealed by using primers 8F-I/907R-I confirms the usefulness of primers with inosine at the 3′ termini in studying the microbial diversity of environmental samples.

scholarly journals Towards a Genome-Based Taxonomy for Prokaryotes

2005 ◽  
Vol 187 (18) ◽  
pp. 6258-6264 ◽  
Author(s):  
Konstantinos T. Konstantinidis ◽  
James M. Tiedje
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Content ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Protein Coding ◽  
Protein Coding Genes ◽  
A Genome ◽  
The 16S Rrna Gene

ABSTRACT The ranks higher than the species in the prokaryotic taxonomy are primarily designated based on phylogenetic analysis of the 16S rRNA gene sequences, but no definite standards exist for the absolute relatedness (measured by 16S rRNA or other means) between the ranks. Accordingly, it remains unknown how comparable the ranks are between different organisms. To gain insights into this question, we studied the relationship between shared gene content and genetic relatedness for 175 fully sequenced strains, using as a robust measure of relatedness the average amino acid identity (AAI) of the shared genes. Our results reveal that adjacent ranks (e.g., phylum versus class) frequently show extensive overlap in terms of genetic and gene content relatedness of the grouped organisms, and hence, the current system is of limited predictive power in this respect. The overlap between nonadjacent ranks (e.g., phylum versus family) is generally limited and attributable to clear inconsistencies of the taxonomy. In addition to providing means for standardizing taxonomy, our AAI-based approach provides a means to evaluate the robustness of alternative genetic markers for phylogenetic purposes. For instance, the 23S rRNA gene was found to be as good a marker as the 16S rRNA gene, while several of the widely distributed protein-coding genes, such as the RNA polymerase and gyrase subunits, show a strong phylogenetic signal, albeit less strong than the rRNA genes (0.78 > R 2 > 0.69 for the protein-coding genes versus R 2 = 0.84 for the rRNA genes). The AAI approach outlined here could contribute significantly to a genome-based taxonomy for all microbial organisms.

scholarly journals Naïve Bayesian Classifier for Rapid Assignment of rRNA Sequences into the New Bacterial Taxonomy

2007 ◽  
Vol 73 (16) ◽  
pp. 5261-5267 ◽  
Author(s):  
Qiong Wang ◽  
George M. Garrity ◽  
James M. Tiedje ◽  
James R. Cole
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Higher Order ◽  
Error Rates ◽  
Bayesian Classifier ◽  
Rrna Gene ◽  
Ribosomal Database Project ◽  
Bacterial Taxonomy ◽  
Variable Regions ◽  
Rrna Sequences

ABSTRACT The Ribosomal Database Project (RDP) Classifier, a naïve Bayesian classifier, can rapidly and accurately classify bacterial 16S rRNA sequences into the new higher-order taxonomy proposed in Bergey's Taxonomic Outline of the Prokaryotes (2nd ed., release 5.0, Springer-Verlag, New York, NY, 2004). It provides taxonomic assignments from domain to genus, with confidence estimates for each assignment. The majority of classifications (98%) were of high estimated confidence (≥95%) and high accuracy (98%). In addition to being tested with the corpus of 5,014 type strain sequences from Bergey's outline, the RDP Classifier was tested with a corpus of 23,095 rRNA sequences as assigned by the NCBI into their alternative higher-order taxonomy. The results from leave-one-out testing on both corpora show that the overall accuracies at all levels of confidence for near-full-length and 400-base segments were 89% or above down to the genus level, and the majority of the classification errors appear to be due to anomalies in the current taxonomies. For shorter rRNA segments, such as those that might be generated by pyrosequencing, the error rate varied greatly over the length of the 16S rRNA gene, with segments around the V2 and V4 variable regions giving the lowest error rates. The RDP Classifier is suitable both for the analysis of single rRNA sequences and for the analysis of libraries of thousands of sequences. Another related tool, RDP Library Compare, was developed to facilitate microbial-community comparison based on 16S rRNA gene sequence libraries. It combines the RDP Classifier with a statistical test to flag taxa differentially represented between samples. The RDP Classifier and RDP Library Compare are available online at http://rdp.cme.msu.edu/ .

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