scholarly journals Predicting Treatment Nonresponse in Hispanic/Latino Children Receiving Silver Diamine Fluoride for Caries Arrest: A Pilot Study Using Machine Learning

2021 ◽  
Vol 2 ◽  
Author(s):  
Ryan Richard Ruff ◽  
Bidisha Paul ◽  
Maria A. Sierra ◽  
Fangxi Xu ◽  
Xin Li ◽  
...  
Keyword(s):  
Machine Learning ◽  
Pilot Study ◽  
Bacterial Species ◽  
Illumina Miseq ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Lasso Regression ◽  
Silver Diamine Fluoride ◽  
Acid Tolerant ◽  
Nonsurgical Therapy

Objectives: Silver diamine fluoride (SDF) is a nonsurgical therapy for the arrest and prevention of dental caries with demonstrated clinical efficacy. Approximately 20% of children receiving SDF fail to respond to treatment. The objective of this study was to develop a predictive model of treatment non-response using machine learning.Methods: An observational pilot study (N = 20) consisting of children with and without active decay and who did and did not respond to silver diamine fluoride provided salivary samples and plaque from infected and contralateral sites. 16S rRNA genes from samples were amplified and sequenced on an Illumina Miseq and analyzed using QIIME. The association between operational taxonomic units and treatment non-response was assessed using lasso regression and artificial neural networks.Results: Bivariate group comparisons of bacterial abundance indicate a number of genera were significantly different between non-responders and those who responded to SDF therapy. No differences were found between non-responders and caries-active subjects. Prevotella pallens and Veillonella denticariosi were retained in full lasso models and combined with clinical variables in a six-input multilayer perceptron.Discussion: The acidogenic and acid-tolerant nature of retained bacterial species may overcome the antimicrobial effects of SDF. Further research to validate the model in larger external samples is needed.

scholarly journals Treatment nonresponse in children receiving silver diamine fluoride for caries: A pilot study

2020 ◽  
Author(s):  
Ryan Richard Ruff ◽  
Bidisha Paul ◽  
Maria A Sierra ◽  
Fangxi Xu ◽  
Yasmi Crystal ◽  
...  
Keyword(s):  
Pilot Study ◽  
Bacterial Species ◽  
Illumina Miseq ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Lasso Regression ◽  
Silver Diamine Fluoride ◽  
Operational Taxonomic Units ◽  
Acid Tolerant ◽  
Nonsurgical Therapy

AbstractObjectives: Silver diamine fluoride (SDF) is a nonsurgical therapy for the arrest and prevention of dental caries with demonstrated clinical efficacy. Approximately 20% of children receiving SDF fail to respond to treatment. The objective of this study was to develop a predictive model of treatment nonresponse using machine learning. Methods: An observational pilot study (N=20) consisting of children with and without active decay and who did and did not respond to silver diamine fluoride provided salivary samples and plaque from infected and contralateral sites. 16S rRNA genes from samples were amplified and sequenced on an Illumina Miseq and analyzed using QIIME. The association between operational taxonomic units and treatment nonresponse was assessed using lasso regression and artificial neural networks. Results: Bivariate group comparisons of bacterial abundance indicate a number of genera were significantly different between nonresponders and those who responded to SDF therapy. No differences were found between nonresponders and caries-active subjects. Prevotella pallens and Veillonella denticariosi were retained in full lasso models and combined with clinical variables in a six-input multilayer perceptron. Discussion: The acidogenic and acid-tolerant nature of retained bacterial species may overcome the antimicrobial effects of SDF. Further research to validate the model in larger external samples is needed.

scholarly journals Consistent Metagenome-Derived Metrics Verify and Delineate Bacterial Species Boundaries

mSystems ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Matthew R. Olm ◽  
Alexander Crits-Christoph ◽  
Spencer Diamond ◽  
Adi Lavy ◽  
Paula B. Matheus Carnevali ◽  
...  
Keyword(s):  
Bacterial Diversity ◽  
Ribosomal Proteins ◽  
Large Scale ◽  
Bacterial Species ◽  
Bacterial Genome ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Species Discrimination ◽  
Bacterial Genomes ◽  
Discrimination Power

ABSTRACT Longstanding questions relate to the existence of naturally distinct bacterial species and genetic approaches to distinguish them. Bacterial genomes in public databases form distinct groups, but these databases are subject to isolation and deposition biases. To avoid these biases, we compared 5,203 bacterial genomes from 1,457 environmental metagenomic samples to test for distinct clouds of diversity and evaluated metrics that could be used to define the species boundary. Bacterial genomes from the human gut, soil, and the ocean all exhibited gaps in whole-genome average nucleotide identities (ANI) near the previously suggested species threshold of 95% ANI. While genome-wide ratios of nonsynonymous and synonymous nucleotide differences (dN/dS) decrease until ANI values approach ∼98%, two methods for estimating homologous recombination approached zero at ∼95% ANI, supporting breakdown of recombination due to sequence divergence as a species-forming force. We evaluated 107 genome-based metrics for their ability to distinguish species when full genomes are not recovered. Full-length 16S rRNA genes were least useful, in part because they were underrecovered from metagenomes. However, many ribosomal proteins displayed both high metagenomic recoverability and species discrimination power. Taken together, our results verify the existence of sequence-discrete microbial species in metagenome-derived genomes and highlight the usefulness of ribosomal genes for gene-level species discrimination. IMPORTANCE There is controversy about whether bacterial diversity is clustered into distinct species groups or exists as a continuum. To address this issue, we analyzed bacterial genome databases and reports from several previous large-scale environment studies and identified clear discrete groups of species-level bacterial diversity in all cases. Genetic analysis further revealed that quasi-sexual reproduction via horizontal gene transfer is likely a key evolutionary force that maintains bacterial species integrity. We next benchmarked over 100 metrics to distinguish these bacterial species from each other and identified several genes encoding ribosomal proteins with high species discrimination power. Overall, the results from this study provide best practices for bacterial species delineation based on genome content and insight into the nature of bacterial species population genetics.

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 Microbial contamination of a University dental clinic in Brazil

2017 ◽  
Vol 15 (4) ◽  
pp. 248
Author(s):  
Gisely Naura Venâncio ◽  
Victor Hugo Marques Coelho ◽  
Thiago Fontanella Cestari ◽  
Maxine Ennata Alves de Almeida ◽  
Carolinie Batista Nobre da Cruz
Keyword(s):  
Culture Media ◽  
Bacterial Species ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Dental Clinics ◽  
Dental Office ◽  
Dental Surface ◽  
The University ◽  
The Chairs ◽  
And Staphylococcus Aureus

Pathogens of the oral cavity of a patient can be transferred to the dental office surfaces by direct contact, aerosol instruments and blood or saliva. The objective of this study was to investigate the microbiological contamination presents in the stands, chairs and spittoons in the University Nilton Lins dental clinics, in Manaus, Amazonas. Samples were collected with sterile swabs and seeded in different microbiological culture media for the isolation of microorganisms collected from each room. Then, assays were carried out for identification of strains isolated from each environment, such as: Gram stain, DNA purification, Amplification of 16s rRNA genes and sequencing. All these experiments were performed in the LBS / ILMD / FIOCRUZ. It was found 40 CFU / mL in the stands, 43 on the chairs and 47 in the spittoons and it was also possible to identify microorganisms like Klebsiella pneumoniae, Shigella sonnei and Staphylococcus aureus. The greatest number of CFUs was found in Clinic 3 and it was observed that the spittoon was the dental surface with the highest number of CFUs. Some of the bacterial species isolated are opportunists, suggesting that more severe biosecurity measures must be taken in order to prevent cross-infection.Pathogens of the oral cavity of a patient can be transferred to the dental office surfaces by direct contact, aerosol instruments and blood or saliva. The objective of this study was to investigate the microbiological contamination presents in the stands, chairs and spittoons in the University Nilton Lins dental clinics, in Manaus, Amazonas. Samples were collected with sterile swabs and seeded in different microbiological culture media for the isolation of microorganisms collected from each room. Then, assays were carried out for identification of strains isolated from each environment, such as: Gram stain, DNA purification, Amplification of 16s rRNA genes and sequencing. All these experiments were performed in the LBS / ILMD / FIOCRUZ. It was found 40 CFU / mL in the stands, 43 on the chairs and 47 in the spittoons and it was also possible to identify microorganisms like Klebsiella pneumoniae, Shigella sonnei and Staphylococcus aureus. The greatest number of CFUs was found in Clinic 3 and it was observed that the spittoon was the dental surface with the highest number of CFUs. Some of the bacterial species isolated are opportunists, suggesting that more severe biosecurity measures must be taken in order to prevent cross-infection.

scholarly journals Distribution of Hydrogen-Producing Bacteria in Tibetan Hot Springs, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Li Ma ◽  
Geng Wu ◽  
Jian Yang ◽  
Liuqin Huang ◽  
Dorji Phurbu ◽  
...  
Keyword(s):  
Community Structure ◽  
Hydrogen Production ◽  
16S Rrna ◽  
High Throughput Sequencing ◽  
Hot Springs ◽  
Illumina Miseq ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
The Tibetan Plateau

Investigating the distribution of hydrogen-producing bacteria (HPB) is of great significance to understanding the source of biological hydrogen production in geothermal environments. Here, we explored the compositions of HPB populations in the sediments of hot springs from the Daggyai, Quzhuomu, Quseyongba, and Moluojiang geothermal zones on the Tibetan Plateau, with the use of Illumina MiSeq high-throughput sequencing of 16S rRNA genes and hydA genes. In the present study, the hydA genes were successfully amplified from the hot springs with a temperature of 46–87°C. The hydA gene phylogenetic analysis showed that the top three phyla of the HPB populations were Bacteroidetes (14.48%), Spirochaetes (14.12%), and Thermotogae (10.45%), while Proteobacteria were absent in the top 10 of the HPB populations, although Proteobacteria were dominant in the 16S rRNA gene sequences. Canonical correspondence analysis results indicate that the HPB community structure in the studied Tibetan hot springs was correlated with various environmental factors, such as temperature, pH, and elevation. The HPB community structure also showed a spatial distribution pattern; samples from the same area showed similar community structures. Furthermore, one HPB isolate affiliated with Firmicutes was obtained and demonstrated the capacity of hydrogen production. These results are important for us to understand the distribution and function of HPB in hot springs.

scholarly journals In-depth analysis of Bacillus anthracis 16S rRNA genes and transcripts reveals intra- and intergenomic diversity and facilitates anthrax detection

2021 ◽  
Author(s):  
Peter Braun ◽  
Fee Zimmermann ◽  
Mathias C Walter ◽  
Sonja Mantel ◽  
Karin Aistleitner ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Bacterial Species ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Close Relative ◽  
Rrna Gene ◽  
Copy Numbers ◽  
Depth Analysis

Analysis of 16S ribosomal RNA (rRNA) genes provides a central means of taxonomic classification of bacterial species. Based on presumed sequence identity among species of the Bacillus cereus sensu lato group, the 16S rRNA genes of B. anthracis have been considered unsuitable for diagnosis of the anthrax pathogen. With the recent identification of a single nucleotide polymorphism in some 16S rRNA gene copies, specific identification of B. anthracis becomes feasible. Here, we designed and evaluated a set of in situ-, in vitro- and in silico-assays to assess the yet unknown 16S-state of B. anthracis from different perspectives. Using a combination of digital PCR, fluorescence in situ hybridization, long-read genome sequencing and bioinformatics we were able to detect and quantify a unique 16S rRNA gene allele of B. anthracis (16S-BA-allele). This allele was found in all available B. anthracis genomes and may facilitate differentiation of the pathogen from any close relative. Bioinformatics analysis of 959 B. anthracis genome data-sets inferred that abundances and genomic arrangements of the 16S-BA-allele and the entire rRNA operon copy-numbers differ considerably between strains. Expression ratios of 16S-BA-alleles were proportional to the respective genomic allele copy-numbers. The findings and experimental tools presented here provide detailed insights into the intra- and intergenomic diversity of 16S rRNA genes and may pave the way for improved identification of B. anthracis and other pathogens with diverse rRNA operons.

Microbial diversity and community structure in agricultural soils suffering from 4 years of Pb contamination

2018 ◽  
Vol 64 (5) ◽  
pp. 305-316 ◽  
Author(s):  
Fengqiu An ◽  
Zhan Diao ◽  
Jialong Lv
Keyword(s):  
Heavy Metal ◽  
Physicochemical Properties ◽  
Agricultural Soils ◽  
Microbial Community Composition ◽  
Illumina Miseq ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Resistant Bacteria ◽  
Available Phosphorus ◽  
Highly Correlated

Heavy metal pollution has become a widespread environmental problem due to rapid economic development. The phylogenetic diversity and structure of microbial communities in lead (Pb)-contaminated Lou soils were investigated using Illumina MiSeq sequencing of 16S rRNA genes. The presence of Pb2+ in soil showed weak impact on the diversity of soil bacteria community, but it influenced the abundance of some genera of bacteria, as well as soil physicochemical properties. We found significant differences in the relative abundances of heavy-metal-resistant bacteria such as Bacillus, Streptococcus, and Arthrobacter at the genus level. Available Pb and total Pb negatively correlated with soil organic matter but positively affected available phosphorus. The abundance of main bacteria phyla was highly correlated with total Pb. The relative abundance of Gemmatimonadetes, Nitrospirae, and Planctomycetes was negatively correlated with total Pb. Collectively, Pb influences both the microbial community composition and physicochemical properties of soil.

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