scholarly journals Digestive tract microbiota of beef cattle that differed in feed efficiency

2020 ◽  
Vol 98 (2) ◽  
Author(s):  
Harvey C Freetly ◽  
Aaron Dickey ◽  
Amanda K Lindholm-Perry ◽  
Richard M Thallman ◽  
John W Keele ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Digestive Tract ◽  
Dry Matter ◽  
Rrna Gene ◽  
Operational Taxonomic Units ◽  
False Discovery ◽  
Gene Database ◽  
The Mean ◽  
Distillers Grain

Abstract We hypothesized cattle that differed in BW gain had different digestive tract microbiota. Two experiments were conducted. In both experiments, steers received a diet that consisted of 8.0% chopped alfalfa hay, 20% wet distillers grain with solubles, 67.75% dry-rolled corn, and 4.25% vitamin/mineral mix (including monensin) on a dry matter basis. Steers had ad libitum access to feed and water. In experiment 1, 144 steers (age = 310 ± 1.5 d; BW = 503 ± 37.2 kg) were individually fed for 105 d. Ruminal digesta samples were collected from eight steers with the greatest (1.96 ± 0.02 kg/d) and eight steers with the least ADG (1.57 ± 0.02 kg/d) that were within ±0.32 SD of the mean (10.1 ± 0.05 kg/d) dry matter. In experiment 2, 66 steers (age = 396 ± 1 d; BW = 456 ± 5 kg) were individually fed for 84 d. Rumen, duodenum, jejunum, ileum, cecum, and colon digesta samples were collected from eight steers with the greatest (2.39 ± 0.06 kg/d) and eight steers with the least ADG (1.85 ± 0.06 kg/d) that were within ±0.55 SD of the mean dry matter intake (11.9 ± 0.1 kg/d). In both studies, DNA was isolated and the V1 to V3 regions of the 16S rRNA gene were sequenced. Operational taxonomic units were classified using 0.03 dissimilarity and identified using the Greengenes 16S rRNA gene database. In experiment 1, there were no differences in the Chao1, Shannon, Simpson, and InvSimpson diversity indexes or the permutation multivariate analysis of variance (PERMANOVA; P = 0.57). The hierarchical test returned six clades as being differentially abundant between steer classifications (P < 0.05). In experiment 2, Chao1, Shannon, Simpson, and InvSimpson diversity indexes and PERMANOVA between steer classified as less or greater ADG did not differ (P > 0.05) for the rumen, duodenum, ileum, cecum, and colon. In the jejunum, there tended to be a difference in the Chao1 (P = 0.09) and Simpson diversity (P = 0.09) indexes between steer classifications, but there was no difference in the Shannon (P = 0.14) and InvSimpson (P = 0.14) diversity indexes. Classification groups for the jejunum differed (P = 0.006) in the PERMANOVA. The hierarchical dependence false discovery rate procedure returned 11 clades as being differentially abundant between steer classifications in the jejunum (P < 0.05). The majority of the OTU were in the Families Corynebacteriaceae and Coriobacteriaceae. This study suggests that intestinal differences in the microbiota of ruminants may be associated with animal performance.

scholarly journals Handling of spurious sequences affects the outcome of high-throughput 16S rRNA gene amplicon profiling

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Sandra Reitmeier ◽  
Thomas C. A. Hitch ◽  
Nicole Treichel ◽  
Nikolaos Fikas ◽  
Bela Hausmann ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Diversity Analysis ◽  
Careful Attention ◽  
Operational Taxonomic Units ◽  
Basic Concepts ◽  
Gnotobiotic Mice ◽  
Mock Communities

Abstract16S rRNA gene amplicon sequencing is a popular approach for studying microbiomes. However, some basic concepts have still not been investigated comprehensively. We studied the occurrence of spurious sequences using defined microbial communities based on data either from the literature or generated in three sequencing facilities and analyzed via both operational taxonomic units (OTUs) and amplicon sequence variants (ASVs) approaches. OTU clustering and singleton removal, a commonly used approach, delivered approximately 50% (mock communities) to 80% (gnotobiotic mice) spurious taxa. The fraction of spurious taxa was generally lower based on ASV analysis, but varied depending on the gene region targeted and the barcoding system used. A relative abundance of 0.25% was found as an effective threshold below which the analysis of spurious taxa can be prevented to a large extent in both OTU- and ASV-based analysis approaches. Using this cutoff improved the reproducibility of analysis, i.e., variation in richness estimates was reduced by 38% compared with singleton filtering using six human fecal samples across seven sequencing runs. Beta-diversity analysis of human fecal communities was markedly affected by both the filtering strategy and the type of phylogenetic distances used for comparison, highlighting the importance of carefully analyzing data before drawing conclusions on microbiome changes. In summary, handling of artifact sequences during bioinformatic processing of 16S rRNA gene amplicon data requires careful attention to avoid the generation of misleading findings. We propose the concept of effective richness to facilitate the comparison of alpha-diversity across studies.

scholarly journals Bacteroidales Diversity in Ring-Billed Gulls (Laurus delawarensis) Residing at Lake Michigan Beaches

2009 ◽  
Vol 75 (6) ◽  
pp. 1525-1533 ◽  
Author(s):  
Sonja N. Jeter ◽  
Colleen M. McDermott ◽  
Patricia A. Bower ◽  
Julie L. Kinzelman ◽  
Melinda J. Bootsma ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Lake Michigan ◽  
Rrna Gene ◽  
Fecal Indicator ◽  
Fecal Samples ◽  
Operational Taxonomic Units ◽  
The North ◽  
The Family ◽  
Sample Representation

ABSTRACT This study investigated the occurrence and diversity of Bacteroidales fecal bacteria in gulls residing in the Great Lakes region. Members of this bacterial order have been widely employed as human and bovine host-specific markers of fecal pollution; however, few studies have focused on gulls, which can be a major source of fecal indicator bacteria and pathogens at beaches. We found a low but consistent occurrence of Bacteroidales in gulls at five beaches in three different counties spanning the Wisconsin shoreline of Lake Michigan. The percentages of gulls positive for Bacteroidales were 4 to 8% at beaches in the southern part of the state and 8 to 50% at beaches in the north. Sequencing of 931 clones from seven gull Bacteroidales 16S rRNA gene libraries revealed a large amount of diversity in both individual and pooled gull fecal samples. Two libraries constructed from pooled gull fecal samples (n = 5 and n = 6) did not have a greater richness of sequences than individual samples, suggesting that even within a single gull diversity is high and an extensive sequencing effort is needed to characterize the populations. Estimates of the numbers of operational taxonomic units (OTUs) for the libraries obtained using different similarity levels revealed a large amount of microdiveristy with a limited number of OTUs at the 95% similarity level. Gull sequences were clustered by the beach from which they were collected, suggesting that there were geographic effects on the distribution of Bacteriodales. More than 53% of the 16S rRNA gene sequences from gulls at the southern beaches were associated with the family Porphyromonadaceae, primarily the genus Parabacteroides, whereas sequences from gulls at the northern beaches were comprised of Bacteroidaceae and Prevotellaceae sequences. Comparison of gull sequences with sequences from goose, canine, raccoon, and sewage sources revealed distinct clusters of closely related gull sequences; however, these sequences were widely dispersed across a dendrogram that included all other sources, including previously characterized gull Bacteroidales from other studies, suggesting that geographic influence or simply sample representation plays a greater role in the observed population structure than strictly the host gut environment.

scholarly journals Greengenes, a Chimera-Checked 16S rRNA Gene Database and Workbench Compatible with ARB

2006 ◽  
Vol 72 (7) ◽  
pp. 5069-5072 ◽  
Author(s):  
T. Z. DeSantis ◽  
P. Hugenholtz ◽  
N. Larsen ◽  
M. Rojas ◽  
E. L. Brodie ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Taxonomic Classification ◽  
Rrna Gene ◽  
Link Type ◽  
Gene Database ◽  
Public Repositories ◽  
Environmental Sequences ◽  
Standard Alignment

ABSTRACT A 16S rRNA gene database (http://greengenes.lbl.gov ) addresses limitations of public repositories by providing chimera screening, standard alignment, and taxonomic classification using multiple published taxonomies. It was found that there is incongruent taxonomic nomenclature among curators even at the phylum level. Putative chimeras were identified in 3% of environmental sequences and in 0.2% of records derived from isolates. Environmental sequences were classified into 100 phylum-level lineages in the Archaea and Bacteria.

scholarly journals Algoriphagus aestuarii sp. nov., a member of the Cyclobacteriaceae isolated from a tidal-flat sediment of the Yellow Sea in Korea

2015 ◽  
Vol 65 (Pt_10) ◽  
pp. 3439-3446 ◽  
Author(s):  
Yong-Taek Jung ◽  
Jung-Sook Lee ◽  
Jung-Hoon Yoon
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Tidal Flat ◽  
Sequence Similarity ◽  
The Yellow Sea ◽  
Rrna Gene ◽  
Phenotypic Properties ◽  
Tidal Flat Sediment ◽  
The Mean ◽  
Type Strains

A Gram-strain-negative, coccoid or oval-shaped, non-motile bacterial strain, designated MDM-1T, was isolated from a tidal-flat sediment on the Korean peninsula. Strain MDM-1T was found to grow optimally at pH 7.0–8.0, at 30 °C and in the presence of 2–3 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain MDM-1T falls within the clade comprising species of the genus Algoriphagus, clustering with the type strains of Algoriphagus halophilus, A. lutimaris, A. chungangensis and A. machipongonensis, with which it exhibited 97.2–98.5 % 16S rRNA gene sequence similarity. Sequence similarities to the type strains of the other recognized species of the genus Algoriphagus were 92.8–97.6 %. Strain MDM-1T was found to contain MK-7 as the predominant menaquinone and iso-C15 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) as the major fatty acids. The major polar lipids were identified as phosphatidylcholine, phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain MDM-1T was determined to be 42.7 mol% and the mean DNA–DNA relatedness with A. halophilus KCTC 12051T, A. lutimaris S1-3T, A. chungangensis KCTC 23759T, A. machipongonensis DSM 24695T and A. ratkowskyi CIP 107452T was 19.7–5.2 %. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain MDM-1T is distinguishable from recognized species of the genus Algoriphagus. On the basis of the data presented, strain MDM-1T is proposed to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus aestuarii sp. nov. is proposed. The type strain is MDM-1T ( = KCTC 42199T = NBRC 110552T).

scholarly journals Bacterial diversity in the saliva of patients with different oral hygiene indexes

2012 ◽  
Vol 23 (4) ◽  
pp. 409-416 ◽  
Author(s):  
Juliana Vianna Pereira ◽  
Luciana Leomil ◽  
Fabíola Rodrigues-Albuquerque ◽  
José Odair Pereira ◽  
Spartaco Astolfi-Filho
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Bacterial Diversity ◽  
Oral Hygiene ◽  
Dental Plaque ◽  
High Index ◽  
Rrna Gene ◽  
Operational Taxonomic Units ◽  
Gene Libraries ◽  
The 16S Rrna Gene

The objective of the present study was to evaluate the bacterial diversity in the saliva of patients with different oral hygiene indexes using of two 16S rRNA gene libraries. Each library was composed of samples from patients with different averages of the differentiated Silness-Löe biofilm index: the first library (A) with an index between 1.0 and 3.0 (considered a high index) and the second library (B) between 0 and 0.5 (considered a low index). Saliva DNA was extracted and the 16S rRNA gene was amplified and cloned. The obtained sequences were compared with those stored at NCBI and RDP GenBank. The saliva of patients with high index presented five known genera - Streptococcus, Granulicatella, Gemella, Veillonella and Peptostreptococcus - and 33.3% of nonculturable bacteria grouped into 23 operational taxonomic units (OTUs). The saliva of patients with low index differed significantly from the first library (p=0.000) and was composed of 42 OTUs distributed into 11 known genera - Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces - including 24.87% of nonculturable bacteria. It was possible to conclude that there is greater bacterial diversity in the saliva of patients with low dental plaque in relation to patients with high dental plaque.

scholarly journals Assessing and Improving Methods Used in Operational Taxonomic Unit-Based Approaches for 16S rRNA Gene Sequence Analysis

2011 ◽  
Vol 77 (10) ◽  
pp. 3219-3226 ◽  
Author(s):  
Patrick D. Schloss ◽  
Sarah L. Westcott
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
Operational Taxonomic Unit ◽  
Rrna Gene ◽  
Operational Taxonomic Units ◽  
Gene Sequence Analysis ◽  
Technical Advances ◽  
Heuristic Clustering

ABSTRACTIn spite of technical advances that have provided increases in orders of magnitude in sequencing coverage, microbial ecologists still grapple with how to interpret the genetic diversity represented by the 16S rRNA gene. Two widely used approaches put sequences into bins based on either their similarity to reference sequences (i.e., phylotyping) or their similarity to other sequences in the community (i.e., operational taxonomic units [OTUs]). In the present study, we investigate three issues related to the interpretation and implementation of OTU-based methods. First, we confirm the conventional wisdom that it is impossible to create an accurate distance-based threshold for defining taxonomic levels and instead advocate for a consensus-based method of classifying OTUs. Second, using a taxonomic-independent approach, we show that the average neighbor clustering algorithm produces more robust OTUs than other hierarchical and heuristic clustering algorithms. Third, we demonstrate several steps to reduce the computational burden of forming OTUs without sacrificing the robustness of the OTU assignment. Finally, by blending these solutions, we propose a new heuristic that has a minimal effect on the robustness of OTUs and significantly reduces the necessary time and memory requirements. The ability to quickly and accurately assign sequences to OTUs and then obtain taxonomic information for those OTUs will greatly improve OTU-based analyses and overcome many of the challenges encountered with phylotype-based methods.

scholarly journals Cellulolytic Bacteria in the Foregut of the Dromedary Camel (Camelus dromedarius)

2012 ◽  
Vol 78 (24) ◽  
pp. 8836-8839 ◽  
Author(s):  
Anjas A. Samsudin ◽  
André-Denis G. Wright ◽  
Rafat Al Jassim
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Species Level ◽  
Neutral Detergent Fiber ◽  
Dromedary Camel ◽  
Rrna Gene ◽  
Cellulolytic Bacteria ◽  
16S Rrna Gene Sequences ◽  
Dromedary Camels ◽  
Operational Taxonomic Units

ABSTRACTForegut digesta from five feral dromedary camels were inoculated into three different enrichment media: cotton thread, filter paper, and neutral detergent fiber. A total of 283 16S rRNA gene sequences were assigned to 33 operational taxonomic units by using 99% species-level identity. LIBSHUFF revealed significant differences in the community composition across all three libraries.

scholarly journals Thalassobius maritimus sp. nov., isolated from seawater

2012 ◽  
Vol 62 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Sooyeon Park ◽  
Mi-Hwa Lee ◽  
Jung-Sook Lee ◽  
Tae-Kwang Oh ◽  
Jung-Hoon Yoon
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Sequence Similarity ◽  
Major Fatty Acid ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Phenotypic Properties ◽  
The Mean ◽  
Type Strains

A Gram-stain-negative, aerobic, motile, rod-shaped bacterial strain, GSW-M6T, was isolated from seawater of Geoje island, Korea, and was subjected to a polyphasic taxonomic study. Strain GSW-M6T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain GSW-M6T clustered with Thalassobius aestuarii, Thalassobius gelatinovorus and Thalassobius mediterraneus. Strain GSW-M6T exhibited 96.2–96.9 % 16S rRNA gene sequence similarity to the type strains of these three Thalassobius species. Strain GSW-M6T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The polar lipid profiles of strain GSW-M6T and the type strains of the three Thalassobius species were similar, with phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and an unidentified lipid as common major components. The DNA G+C content of strain GSW-M6T was 57 mol%. The mean level of DNA–DNA relatedness between strain GSW-M6T and the type strain of Thalassobius gelatinovorus was 17 %. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, enabled strain GSW-M6T to be differentiated from recognized species of the genus Thalassobius. On the basis of the data presented, strain GSW-M6T is considered to represent a novel species of the genus Thalassobius, for which the name Thalassobius maritimus sp. nov. is proposed. The type strain is GSW-M6T ( = KCTC 23347T  = CCUG 60021T).

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