Identification of competence genes in streptococcus mutans by functional genomic analysis

by Janet Lee

Written in English
Published: Pages: 89 Downloads: 720
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Edition Notes

Statementby Janet Lee.
The Physical Object
Paginationix, 89 leaves :
Number of Pages89
ID Numbers
Open LibraryOL19082481M
ISBN 100612688577

Isolation and Identification of Streptococcus mutans from Dental Caries by Using SM gene that competence genes as well as the sgp and dgk genes may play important roles in S. mutans biofilm. As a major etiological agent of human dental caries, Streptococcus mutans resides primarily in biofilms that form on the tooth surfaces, also known as dental plaque. In addition to caries, S. mutans is responsible for cases of infective endocarditis with a subset of strains being indirectly implicated with the onset of additional extraoral pathologies. This chapter outlines the up-regulation of genes in response to the competence-stimulating peptide (CSP), as well as a number of recent discoveries indicating that the coordination of gene expression mediated among neighboring Streptococcus pneumoniae cells by CSP makes important contributions to the interaction of this pathogen with its human host, and thus has significance beyond the. The early genes of the competence-signaling pathway in S. mutans are regulated by inputs from peptide signals, as well as by multiple sensors of environmental stress and cellular homeostasis (17 – 24).Among the signaling pathways, perhaps the best characterized is the ComDE two-component system (TCS), which detects a specific peptide signal and activates genetic competence and the production.

Aims: To identify the genes regulated by RR11, the regulator of the Streptococcus mutans HK/RR11 two‐component system. Methods and Results: The S. mutans RR11‐encoding gene was inactivated, and the effects of gene disruption on the cell’s ability to form biofilms under stresses and acquire extracellular DNA were tested. Biofilm was reduced in cells lacking RR11 following exposure to. Horizontal gene transfer is one of the principal mechanisms driving the evolution of microorganisms. One can induce from this “archeological evidence” that genetic exchange between bacteria occurs fairly frequently. This chapter describes the examples of genetic exchange in biofilms as they have been observed in the laboratory. Abstract. Streptococcus mutans is the primary causative agent involved in dental caries in humans. Among important virulence factors of this pathogen, its ability to form and sustain a polysaccharide-encased biofilm (commonly called dental plaque) is vital not only to its survival and persistence in the oral cavity, but also for its pathogenicity as well. Streptococcus pneumoniae is one of the most important model organisms for studies on natural genetic transformation in bacteria. The prevalence of this gene exchange mechanism in the genus Streptococcus has not been subjected to systematic investigations, but it has been known for decades that only a few streptococcal species develop the competent state spontaneously when grown under.

  Identification of an alternative sigma factor gene (comX) and a conserved comX promoter in S. suis. Inspection of the S. suis strain P1/7 genome revealed a single homologue of comX (SSU) with highest similarity to comX of S. pneumoniae (%) and comX in S. mutans (%), both of which mediate expression of the late competence S. suis comX locus bears . Further genetic and molecular analysis led to the discovery of the lactate oxidase (lox) gene of S. oligofermentans as responsible for this biological activity. Consequently, the lox mutant of S. oligofermentans also showed dramatically reduced inhibitory effects against S. mutans and also exhibited greatly impaired growth in the presence of.

Identification of competence genes in streptococcus mutans by functional genomic analysis by Janet Lee Download PDF EPUB FB2

Streptococcus mutans is the leading cause of dental caries (tooth decay) worldwide and is considered to be the most cariogenic of all of the oral streptococci. The genome of S. mutans UA, a serotype c strain, has been completely sequenced and is composed of 2, base pairs.

It contains 1, ORFs, 63% of which have been assigned putative by: Streptococcus mutans, the primary etiological agent of human dental caries, is an obligate biofilm-forming goals of this study were to identify the gene(s) required for biofilm formation by this organism and to elucidate the role(s) that some of the known global regulators of gene expression play in controlling biofilm by:   Streptococcus mutans, the primary etiological agent of human dental caries, is an obligate biofilm-forming bacterium.

The goals of this study were to identify the gene(s) required for biofilm formation by this organism and to elucidate the role(s) that some of the known global regulators of gene expression play in controlling biofilm formation.

In S. mutans UA, the brpA gene (for biofilm Cited by:   Transposon mutagenesis coupled with next-generation DNA sequencing (Tn-seq) is a powerful tool for discovering regions of the genome that are required for the survival of bacteria in different environments.

We adapted this technique to the dental caries pathogen Streptococcus mutans UA and identified 11% of the genome as essential, with many genes encoding products required Cited by:   Identification of a novel bacteriocin Lin Zeng, Sang-Joon Ahn, Stephen J.

Hagen, Robert A. Burne, Effects of Carbohydrate Source on Genetic Competence in Streptococcus mutans, Applied and Saswati Biswas, Min Zhu, Effects of DNA Methylation on Expression of Virulence Genes in Streptococcus mutans, Applied and Cited by: The frequencies of 21 competence genes were analyzed in 94 genotypes of Streptococcus include those of a main regulatory system (comCDE), structural, and other regulatory orthologues identified in the genome of strain UAPCR and Southern blot analysis revealed that all genes are widespread within the species.

Random mutagenesis of S. mutans. The random mutagenesis of S. mutans was carried out as described previously ().Briefly, we constructed an S. mutans Xc genomic library by inserting a complete Sau3AI digest of the S. mutans Xc chromosome into the BamHI site of pResEmBBN. pResEmBBN can be used as an integration vector for gene inactivation by a single crossover with the streptococcal.

Streptococcus oralis is an early colonizer bacterium in dental plaques and is considered a potential pathogen of infective endocarditis (IE) this study, we built a complete genome map of Streptococcus oralis strain SOT, Streptococcus oralis strain SOD and Streptococcus infantis strain SO and performed comparative genomic analysis among these three strains.

Identification of the streptococcal competence-pheromone receptor. Mol Microbiol. Aug; 21 (4)– Hui FM, Morrison DA. Genetic transformation in Streptococcus pneumoniae: nucleotide sequence analysis shows comA, a gene required for competence induction, to be a member of the bacterial ATP-dependent transport protein family.

The aerotolerant anaerobe Streptococcus pneumoniae is a human pathogen showing high transformability by soluble DNA. Central metabolism in these bacteria is classically described as homolactic and genome analysis revealed the absence of most of the genes involved in aerobic respiration (29 genes searched for), the tricarboxylic acid (TCA) cycle, and gluconeogenesis ().

Lee, J.H., et al. Genetic transformation in Streptococcus mutans: identification of competence genes by functional genomic analysis. Abstracts of the st Annual General Meeting of the American Society for Microbiology.

Orlando, Florida, USA. (Abstr. As with many other gram-positive organisms, the genome of Streptococcus pneumoniae proved difficult to sequence. The majority of insertion sequence (IS) elements have undergone insertions, deletions, and/or point mutations that result in frame shifted or otherwise nonfunctional transposase genes.

A primary role for the numerous repeats might be their potential contribution to genomic. The frequencies of 21 competence genes were analyzed in 94 genotypes of Streptococcus mutans.

These include those of a main regulatory system (comCDE), structural, and other regulatory orthologues identified in the genome of strain UA PCR and Southern blot analysis revealed that all genes are widespread within the species. Development of Competence for Genetic Transformation of Streptococcus mutans in a Chemically Defined Medium Kunal Desai,a Lauren Mashburn-Warren,b Michael J.

Federle,b,c and Donald A. Morrisona comR genes, and a functional oligopeptide permease (4,17 24). Mashburn-Warren et al. (17) recently reported that a second. Streptococcus gallolyticus subsp. gallolyticus, a member of the group D streptococci, is normally found in the bovine rumen and human gut.

It is an opportunistic pathogen that was recently determined to be a bacterial driver of colorectal cancer, in addition to causing other diseases, such as infective endocarditis, bacteremia, neonatal meningitis, and septicemia.

Abstract. C LARKE () first isolated and described a streptococcus from a human carious lesion and inferred that it was a potential causative agent of dental caries.

He named the organism Streptococcus observation went unnoticed for some 35 years until O RLAND () demonstrated that enterococci could cause dental caries in germ-free rats and F ITZGERALD and colleagues (F.

Genomic overview. We began with a bioinformatic analysis of 20 S. sanguinis strains: the oral isolate SK36, which we had sequenced previously (), and 19 other strains that were draft sequenced as part of the Human Microbiome of these strains were oral isolates, with the remaining 10 isolated from IE patients ().As is typical, the IE isolates were from blood, except perhaps SK1.

In Streptococcus mutans, competence for genetic transformation and biofilm formation are dependent on the two-component signal transduction system ComDE together with the inducer peptide pheromone competence-stimulating peptide (CSP) (encoded by comC). Here, it is shown that the same system is also required for expression of the nlmAB genes, which encode a two-peptide nonlantibiotic.

Introduction. Streptococcus mutans is a principal microorganism contributing to the ubiquitous oral infectious disease dental caries (Loesche, ).Recent improvements in DNA sequencing platforms and intensified analysis of the oral microbiome have supported the ecological plaque hypothesis that describes the etiology of the development of the most common oral infectious.

The potential for a similar means of gene transfer in other streptococci is suggested by the finding of competence genes in many of the genome Canada) described the S.

mutans system and presented the functional analysis of a new two-component involved in biofilm formation and acid resistance in Streptococcus mutans. This chapter addresses how genomic sciences are revealing why Streptococcus mutans is such an effective caries pathogen in humans. Recognizing the importance of central metabolism and acid production in pathogenesis by S.

mutans, many laboratories began functional studies in the post-genomic era with a focus on gene regulation, stress tolerance, and biofilm formation.

Candidate cgMLST target gene set. We began by identifying genes that were well-suited to incorporation into our cgMLST scheme by filtering the S. mutans UA (GenBank accession number NC_) reference genome based upon minimum gene length, gene overlap, and start/stop codon led to the identification of 1, genes, and this number was further winnowed to 1, genes.

Lemos, J. A., Chen, Y. & Burne, R. Genetic and physiologic analysis of the groE operon and role of the HrcA repressor in stress gene regulation and acid tolerance in Streptococcus mutans. Streptococcus mutans, a member of the human oral flora, is a widely recognized etiological agent of dental caries.

The cariogenic potential of S. mutans is related to its ability to metabolize a wide variety of sugars, form a robust biofilm, produce copious amounts of lactic acid, and thrive in the acid environment that it generates.

The remarkable genetic variability present within the. Streptococcus mutans is one of several members of the oral indigenous biota linked with severe early childhood caries (S-ECC).

Because most humans harbor S. mutans, but not all manifest disease, it has been proposed that the strains of S. mutans associated with S-ECC are genetically distinct from those found in caries-free (CF) children. The objective of this study was to identify common DNA.

We identified a gene (atlA) encoding autolytic activity from Streptococcus mutans Xc. The AtlA protein predicted to be encoded by atlA is composed of amino acids with a molecular weight ofand has a conserved β-1,4- N -acetylmuramidase (lysozyme) domain in the C-terminal portion. Sodium dodecyl sulfate extracts of strain Xc showed two major bacteriolytic bands with molecular.

Abstract. AtlA is a major cell-lytic enzyme called autolysin in Streptococcus this study, we identified the atlg gene-encoding autolysin (Atlg), consisting of residues from Streptococcus sobrinus DP, and confirmed lytic activity of recombinant Atlg by zymography of S.

sobrinus cells. An atlA-inactivated mutant was constructed in S. mutans Xc, and the atlg gene product was. Streptococcus mutans is a major pathogen causing human dental caries. As a Gram-positive bacterium with a small genome (about 2 Mb) it is considered a.

These methods include ortholog identificat genomic intrinsic feature analy gene evolution r phylogenetic conservat network analysis 41. Trigger factor is a ribosome-associated peptidyl-prolyl cis/trans isomerase that is highly conserved in most bacteria.

A gene, designated ropA, encoding an apparent trigger factor homologue, was identified in Streptococcus mutans, the primary etiological agent of human dental caries.

Inactivation of ropA had no major impact on growth rate in planktonic cultures under the conditions tested. Regulation of competence and gene expression in Streptococcus mutans by the RcrR transcriptional regulator.

Mol Oral Microbiol. ; – [PMC free article] Seaton K, Ahn S-J, Sagstetter AM, et al. A transcriptional regulator and ABC transporters link stress tolerance, (p)ppGpp, and genetic competence in Streptococcus mutans.

J Bacteriol.We anticipate that completion of this project will lead to the identification of novel regulatory pathway for expression of stress response genes in S.

mutans. Moreover, knowledge acquired from this project can also be extended to analysis of other important gram-positive pathogens such as S. pnemoniae and S. pyogenes, and may lead to the.From a common ancestor, Streptococcus pneumoniae and Streptococcus mitis evolved in parallel into one of the most important pathogens and a mutualistic colonizer of humans, respectively.

This evolutionary scenario provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. We performed detailed comparisons of .