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 Bacterial Diversity Profiling around the Orca Seamount in the Bransfield Strait, Antarctica, Based on 16S rRNA Gene Amplicon Sequences

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Wilbert Serrano ◽  
Raul M. Olaechea ◽  
Luis Cerpa ◽  
Jose Herrera ◽  
Aldo Indacochea
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Bacterial Diversity ◽  
Hydrothermal Vent ◽  
Hydrothermal Activity ◽  
Rrna Gene ◽  
Diversity Pattern ◽  
Submarine Volcanism ◽  
Data Profiling ◽  
The 16S Rrna Gene

ABSTRACT Hydrothermal vent activity is often associated with submarine volcanism. Here, we investigated the presence of microorganisms related to hydrothermal activity in the Orca seamount. Data profiling of the 16S rRNA gene amplicon sequences revealed a diversity pattern dominated mainly by the phyla Proteobacteria, Acidobacteria, Planctomycetes, and Bacteroidetes.

scholarly journals Methanogenic Population and CH4Production in Swedish Dairy Cows Fed Different Levels of Forage

2012 ◽  
Vol 78 (17) ◽  
pp. 6172-6179 ◽  
Author(s):  
R. Danielsson ◽  
A. Schnürer ◽  
V. Arthurson ◽  
J. Bertilsson
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Dairy Cows ◽  
Rflp Analysis ◽  
Rrna Gene ◽  
Content Type ◽  
Methanobrevibacter Ruminantium ◽  
Gene Libraries ◽  
Swedish Dairy ◽  
The 16S Rrna Gene

ABSTRACTMethanogenic community structure, methane production (CH4), and volatile fatty acid (VFA) profiles were investigated in Swedish dairy cows fed a diet with a forage/concentrate ratio of 500/500 or 900/100 g/kg of dry matter (DM) of total DM intake (DMI). The rumen methanogenic population was evaluated using terminal restriction fragment length polymorphism (T-RFLP) analysis, 16S rRNA gene libraries, and quantitative real-time PCR (qRT-PCR). Mean CH4yields did not differ (P> 0.05) between diets, being 16.9 and 20.2 g/kg DMI for the 500/500 and 900/100 diets, respectively. The T-RFLP analysis revealed that populations differed between individual cows and that each individual population responded differently to the diets. The 16S rRNA gene libraries revealed thatMethanobrevibacterspp. dominated for both diets. CH4production was positively correlated with a dominance of sequences representing T-RFs related toMethanobrevibacter thaueri,Methanobrevibacter millerae, andMethanobrevibacter smithiirelative toMethanobrevibacter ruminantiumandMethanobrevibacter olleyae. Total numbers of methanogens and total numbers ofMethanobacterialeswere significantly higher with the 500/500 diet (P< 0.0004 andP< 0.002, respectively). However, no relationship was found between CH4production and total number of methanogens. No differences were seen in total VFA, propionic acid, or acetic acid contents, but the molar proportion of butyric acid in the rumen was higher for the 500/500 diet than for the 900/100 diet (P< 0.05). Interestingly, the results also revealed that a division of the identified methanogenic species into two groups, suggested in the work of King et al. (E. E. King, R. P. Smith, B. St-Pierre, and A. D. G. Wright, Appl. Environ. Microbiol.77:5682–5687, 2011), increased the understanding of the variation in CH4production between different cows.

scholarly journals Rumen Microbial Population Dynamics during Adaptation to a High-Grain Diet

2010 ◽  
Vol 76 (22) ◽  
pp. 7482-7490 ◽  
Author(s):  
S. C. Fernando ◽  
H. T. Purvis ◽  
F. Z. Najar ◽  
L. O. Sukharnikov ◽  
C. R. Krehbiel ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Microbial Population ◽  
Rflp Analysis ◽  
Rrna Gene ◽  
Gene Libraries ◽  
The 16S Rrna Gene ◽  
Number Of Bacteria

ABSTRACT High-grain adaptation programs are widely used with feedlot cattle to balance enhanced growth performance against the risk of acidosis. This adaptation to a high-grain diet from a high-forage diet is known to change the rumen microbial population structure and help establish a stable microbial population within the rumen. Therefore, to evaluate bacterial population dynamics during adaptation to a high-grain diet, 4 ruminally cannulated beef steers were adapted to a high-grain diet using a step-up diet regimen containing grain and hay at ratios of 20:80, 40:60, 60:40, and 80:20. The rumen bacterial populations were evaluated at each stage of the step-up diet after 1 week of adaptation, before the steers were transitioned to the next stage of the diet, using terminal restriction fragment length polymorphism (T-RFLP) analysis, 16S rRNA gene libraries, and quantitative real-time PCR. The T-RFLP analysis displayed a shift in the rumen microbial population structure during the final two stages of the step-up diet. The 16S rRNA gene libraries demonstrated two distinct rumen microbial populations in hay-fed and high-grain-fed animals and detected only 24 common operational taxonomic units out of 398 and 315, respectively. The 16S rRNA gene libraries of hay-fed animals contained a significantly higher number of bacteria belonging to the phylum Fibrobacteres, whereas the 16S rRNA gene libraries of grain-fed animals contained a significantly higher number of bacteria belonging to the phylum Bacteroidetes. Real-time PCR analysis detected significant fold increases in the Megasphaera elsdenii, Streptococcus bovis, Selenomonas ruminantium, and Prevotella bryantii populations during adaptation to the high-concentrate (high-grain) diet, whereas the Butyrivibrio fibrisolvens and Fibrobacter succinogenes populations gradually decreased as the animals were adapted to the high-concentrate diet. This study evaluates the rumen microbial population using several molecular approaches and presents a broader picture of the rumen microbial population structure during adaptation to a high-grain diet from a forage diet.

16S rRNA Gene Primer Validation for Bacterial Diversity Analysis of Vegetable Products

2018 ◽  
Vol 81 (5) ◽  
pp. 848-859
Author(s):  
MIYO NAKANO
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Bacterial Diversity ◽  
High Throughput Sequencing ◽  
Animal Feed ◽  
Rrna Gene ◽  
Universal Primer ◽  
Food Matrices ◽  
Taxonomic Groups ◽  
The 16S Rrna Gene

ABSTRACT High-throughput sequencing of the 16S rRNA gene enhances understanding of microbial diversity from complex environmental samples. The 16S rRNA gene is currently the most important target in bacterial evolution and ecology studies, particularly for determination of phylogenetic relationships among taxa, exploration of bacterial diversity in a given environment, and quantification of the relative abundance of taxa at various levels. However, some parts of the conserved region of the bacterial 16S rRNA gene are similar to the conserved regions of plant chloroplasts and eukaryotic mitochondria. Therefore, if DNA contains a large amount of nontarget DNA, this nontarget DNA can be coamplified and consequently produce useless sequence reads. We experimentally assessed the primer pair 335f/769r and the widely used bacterial primer pair SD (S-D-Bact-0341-b-S-17/S-D-Bact-0785-a-A-21). The primer pair 335f/769r was examined for its ability to amplify bacterial DNA in plant and animal feed samples by using the single-strand confirmation polymorphism method. In our present study, these primer pairs were validated for microbial community structure analysis with complex food matrices by using next-generation sequencing. The sequencing results revealed that the primer pair 335f/769r successfully resulted in fewer chloroplast and mitochondrial sequence reads than generated by the universal primer pair SD and therefore is comparatively suitable for metagenomic analyses of complex food matrices, particularly those that are rich in plant DNA. Additionally, some taxonomic groups were missed entirely when only the SD primer pair was used.

scholarly journals Lean Breed Landrace Pigs Harbor Fecal Methanogens at Higher Diversity and Density than Obese Breed Erhualian Pigs

Archaea ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-heng Luo ◽  
Yong Su ◽  
André-Denis G. Wright ◽  
Ling-li Zhang ◽  
Hauke Smidt ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Real Time ◽  
Real Time Pcr ◽  
Rrna Gene ◽  
Pig Breeds ◽  
Operational Taxonomic Units ◽  
Gene Copies ◽  
Gene Libraries ◽  
Landrace Pig

The diversity of fecal methanogens of Erhualian (obese type) and Landrace (lean type) pigs was examined using separate 16S rRNA gene libraries for each breed. A total of 763 clones were analyzed; 381 from the Erhualian library and 382 from the Landrace library were identified belonging to the genus Methanobrevibacter. Others were identified belonging to the genus Methanosphaera. The two libraries showed significant differences in diversity (P<0.05) and composition (P<0.0001). Only two operational taxonomic units (OTUs) were found in both libraries, whereas six OTUs were found only in the Erhualian library and 23 OTUs were found only in the Landrace library. Real-time PCR showed that the abundance of fecal methanogens in Landrace pigs was significantly higher than that in Erhualian pigs (P<0.05). Results showed that the Landrace pig (lean) harbored a greater diversity and higher numbers of methanogenmcrAgene copies than the Erhualian pig (obese). These differences may be related to the fatness or leanness in these two pig breeds. The results provide new leads for further investigations on the fat storage of pigs or even humans.

scholarly journals Introducing DOTUR, a Computer Program for Defining Operational Taxonomic Units and Estimating Species Richness

2005 ◽  
Vol 71 (3) ◽  
pp. 1501-1506 ◽  
Author(s):  
Patrick D. Schloss ◽  
Jo Handelsman
Keyword(s):  
Species Richness ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Computer Program ◽  
Genetic Distances ◽  
Rrna Gene ◽  
Sargasso Sea ◽  
Operational Taxonomic Units ◽  
Typical Sequence ◽  
Gene Libraries

ABSTRACT Although copious qualitative information describes the members of the diverse microbial communities on Earth, statistical approaches for quantifying and comparing the numbers and compositions of lineages in communities are lacking. We present a method that addresses the challenge of assigning sequences to operational taxonomic units (OTUs) based on the genetic distances between sequences. We developed a computer program, DOTUR, which assigns sequences to OTUs by using either the furthest, average, or nearest neighbor algorithm for each distance level. DOTUR uses the frequency at which each OTU is observed to construct rarefaction and collector's curves for various measures of richness and diversity. We analyzed 16S rRNA gene libraries derived from Scottish and Amazonian soils and the Sargasso Sea with DOTUR, which assigned sequences to OTUs rapidly and reliably based on the genetic distances between sequences and identified previous inconsistencies and errors in assigning sequences to OTUs. An analysis of the two 16S rRNA gene libraries from soil demonstrated that they do not contain enough sequences to support a claim that they contain different numbers of bacterial lineages with statistical confidence (P > 0.05), nor do they contain enough sequences to provide a robust estimate of species richness when an OTU is defined as containing sequences that are no more than 3% different from each other. In contrast, the richness of OTUs at the 3% level in the Sargasso Sea collection began to plateau after the sampling of 690 sequences. We anticipate that an equivalent extent of sampling for soil would require sampling more than 10,000 sequences, almost 100 times the size of typical sequence collections obtained from soil.

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