Dataset Information

Actinomyces spp. gene expression in root caries lesions.

ABSTRACT:

Background

The studies of the distribution of Actinomyces spp. on carious and non-carious root surfaces have not been able to confirm the association of these bacteria with root caries, although they were extensively implicated as a prime suspect in root caries.

Objective

The aim of this study was to observe the gene expression of Actinomyces spp. in the microbiota of root surfaces with and without caries.

Design

The oral biofilms from exposed sound root surface (SRS; n=10) and active root caries (RC; n=30) samples were collected. The total bacterial RNA was extracted, and the mRNA was isolated. Samples with low RNA concentration were pooled, yielding a final sample size of SRS=10 and RC=9. Complementary DNA (cDNA) libraries were prepared and sequenced on an Illumina(®) HiSeq 2500 system. Sequence reads were mapped to eight Actinomyces genomes. Count data were normalized using DESeq2 to analyse differential gene expression applying the Benjamini-Hochberg correction (false discovery rate [FDR]<0.001).

Results

Actinomyces spp. had similar numbers of reads (Mann-Whitney U-test; p>0.05), except for Actinomyces OT178 (p=0.001) and Actinomyces gerencseriae (p=0.004), which had higher read counts in the SRS. Genes that code for stress proteins (clp, dnaK, and groEL), enzymes of glycolysis pathways (including enolase and phosphoenolpyruvate carboxykinase), adhesion (Type-2 fimbrial and collagen-binding protein), and cell growth (EF-Tu) were highly - but not differentially (p>0.001) - expressed in both groups. Genes with the most significant upregulation in RC were those coding for hypothetical proteins and uracil DNA glycosylase (p=2.61E-17). The gene with the most significant upregulation in SRS was a peptide ABC transporter substrate-binding protein (log2FC=-6.00, FDR=2.37E-05).

Conclusion

There were similar levels of Actinomyces gene expression in both sound and carious root biofilms. These bacteria can be commensal in root surface sites but may be cariogenic due to survival mechanisms that allow them to exist in acid environments and to metabolize sugars, saving energy.

SUBMITTER: Dame-Teixeira N

PROVIDER: S-EPMC5027334 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Actinomyces spp. gene expression in root caries lesions.

Dame-Teixeira Naile N Parolo Clarissa Cavalcanti Fatturi CC Maltz Marisa M Tugnait Aradhna A Devine Deirdre D Do Thuy T

Journal of oral microbiology 20160916

<h4>Background</h4>The studies of the distribution of Actinomyces spp. on carious and non-carious root surfaces have not been able to confirm the association of these bacteria with root caries, although they were extensively implicated as a prime suspect in root caries.<h4>Objective</h4>The aim of this study was to observe the gene expression of Actinomyces spp. in the microbiota of root surfaces with and without caries.<h4>Design</h4>The oral biofilms from exposed sound root surface (SRS; n=10) ...[more]

PMID: 27640531

Similar Datasets

Project description:BACKGROUND:Actinomyces oris is a Gram-positive bacterium that has been associated with healthy and diseased sites in the human oral cavity. Most pathogenic bacteria require iron to survive, and in order to acquire iron in the relatively iron-scarce oral cavity A. oris has been shown to produce iron-binding molecules known as siderophores. The genes encoding these siderophores and transporters are thought to be regulated by the amount of iron in the growth medium and by the metal-dependent repressor, AmdR, which we showed previously binds to the promoter of proposed iron-regulated genes. OBJECTIVE:The purpose of this study was to characterize siderophore and associated iron transport systems in A. oris. DESIGN:We examined gene expression of the putative iron transport genes fetA and sidD in response to low- and high-iron environments. One of these genes, sidD, encoding a putative Fe ABC transporter protein, was insertionally inactivated and was examined for causing growth defects. To gain a further understanding of the role of iron metabolism in oral diseases, clinical isolates of Actinomyces spp. were examined for the presence of the gene encoding AmdR, a proposed global regulator of iron-dependent gene expression in A. oris. RESULTS:When A. oris was grown under iron-limiting conditions, the genes encoding iron/siderophore transporters fetA and sidD showed increased expression. One of these genes (sidD) was mutated, and the sidD::Km strain exhibited a 50% reduction in growth in late log and stationary phase cells in media that contained iron. This growth defect was restored when the sidD gene was provided in a complemented strain. We were able to isolate the AmdR-encoding gene in seven clinical isolates of Actinomyces. When these protein sequences were aligned to the laboratory strain, there was a high degree of sequence similarity. CONCLUSIONS:The growth of the sidD::Km mutant in iron-replete medium mirrored the growth of the wild-type strain grown in iron-limiting medium, suggesting that the sidD::Km mutant was compromised in iron uptake. The known iron regulator AmdR is well conserved in clinical isolates of A. oris. This work provides additional insight into iron metabolism in this important oral microbe.

Project description:Prunus rootstock belonging to subgenera Amygdalus (peach), Prunus (plum) and Cerasus (cherry) are either from the same species as the scion or another one. The number of inter-species (including inter-subgenera) hybrids has increased as a result of broadening the genetic basis for stress (biotic and abiotic) resistance/tolerance. Identifying genes associated with important traits and responses requires expression analysis. Relative quantification is the simplest and most popular alternative, which requires reference genes (housekeeping) to normalize RT-qPCR data. However, there is a scarcity of validated housekeeping genes for hybrid Prunus rootstock species. This research aims to increase the number of housekeeping genes suitable for Prunus rootstock expression analysis. Twenty-one candidate housekeeping genes were pre-selected from previous RNAseq data that compared the response of root transcriptomes of two rootstocks subgenera to hypoxia treatment, 'Mariana 2624' (P. cerasifera Ehrh.× P. munsoniana W. Wight & Hedrick), and 'Mazzard F12/1' (P. avium L.). Representing groups of low, intermediate or high levels of expression, the genes were assayed by RT-qPCR at 72 hours of hypoxia treatment and analyzed with NormFinder software. A sub-set of seven housekeeping genes that presented the highest level of stability were selected, two with low levels of expression (Unknown 3, Unknown 7) and five with medium levels (GTB 1, TUA 3, ATPase P, PRT 6, RP II). The stability of these genes was evaluated under different stress conditions, cold and heat with the hybrid 'Mariana 2624' and N nutrition with the hybrids 'Colt' (P. avium × P. pseudocerasus Lindl.) and 'Garnem' [P. dulcis Mill.× (P. persica L.× P. davidiana Carr.)]. The algorithms of geNorm and BestKeeper software also were used to analyze the performance of these genes as housekeepers. Stability rankings varied according to treatments, genotypes and the software for evaluation, but the gene GBT 1 often had the highest ranking. However, most of the genes are suitable depending on the stressor and/or genotype to be evaluated. No optimal number of reference genes could be determined with geNorm software when all conditions and genotypes were considered. These results strongly suggest that relative RT-qPCR should be analyzed separately with their respective best housekeeper according to the treatment and/or genotypes in Prunus spp. rootstocks.

Dataset Information

Actinomyces spp. gene expression in root caries lesions.

Background

Objective

Design

Results

Conclusion

Publications

Actinomyces spp. gene expression in root caries lesions.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets