Difference between revisions of "Streptococcus salivarius"

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{{Biorealm Genus}}
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=1. Classification=
 
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==a. Higher order taxa==
==Classification==
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Domain; Phylum; Class; Order; Family; Genus
 
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Include this section if your Wiki page focuses on a specific taxon/group of organisms
 
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=2. Description and significance=
 
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Describe the appearance, habitat, etc. of the organism, and why you think it is important.
===Higher order taxa===
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*Include as many headings as are relevant to your microbe. Consider using the headings below, as they will allow readers to quickly locate specific information of major interest*
 
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=3. Genome structure=
Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae; Streptococcus; Streptococcus salivarius
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Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
 
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=4. Cell structure=
===Species===
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Interesting features of cell structure. Can be combined with “metabolic processes”
 
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=5. Metabolic processes=
{|
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Describe important sources of energy, electrons, and carbon (i.e. trophy) for the organism/organisms you are focusing on, as well as important molecules it/they synthesize(s).
| height="10" bgcolor="#FFDF95" |
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=6. Ecology=
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Tree&id=2&lvl=3&lin=f&keep=1&srchmode=1&unlock Taxonomy]'''
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Habitat; symbiosis; contributions to the environment.
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=7. Pathology=
 
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How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
''Streptococcus salivarius''
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=7. Key microorganisms=
 
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Include this section if your Wiki page focuses on a microbial process, rather than a specific taxon/group of organisms
==Description and significance==
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=8. Current Research=
 
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Include information about how this microbe (or related microbes) are currently being studied and for what purpose
 
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=9. References=
 
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It is required that you add at least five primary research articles (in same format as the sample reference below) that corresponds to the info that you added to this page.
''Streptococcus salivarius'' is the principal commensal bacterium of the oral cavity in humans. ''S. salivarius'' is a normal inhabitant of the upper respiratory tract.  It may enter the blood stream by accident during dental work or when brushing the teeth.  It is the first bacterium which colonizes the dental plaque, before being joined by numerous other species of various genera [http://www.cns.fr/externe/English/Projets/Projet_MB/organisme_MB.html [6]]. It therefore seems to be the pioneer in colonizing dental plaque, it creates favorable conditions so other species can begin to colonize. It is also a bacterium which plays the role of moderator, permitting the implantation of bacteria which are harmful to the health of the oral cavity.
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[Sample reference] Faller, A., and Schleifer, K. "Modified Oxidase and Benzidine Tests for Separation of Staphylococci from Micrococci". Journal of Clinical Microbiology. 1981. Volume 13. p. 1031-1035.
 
 
Better knowledge of the molecular and physiologic factors which allow it to colonize dental plaque and to interact with other species will help in designing strategies for the prevention of cavities, especially in children [http://www.cns.fr/externe/English/Projets/Projet_MB/organisme_MB.html [6]].  Also, greater knowledge of this organism can help with research on mouth odor.
 
 
 
Moreover, when this bacterium enters the bloodstream it is found that it may cause septicemia in neutropenic patients, a condition that shows a abnormal low level amounts of neutrophils in the blood. Neutrophils are also known as white blood cells and are involved in the body’s immune response to infections [http://www.phac-aspc.gc.ca/msds-ftss/msds149e.html [5]].  Also, ''Streptococcus salivarius'' is used to treat patients with atypical pneumonia, which is an illness of the lungs where they become flooded with fluid.
 
 
 
==Genome structure==
 
 
 
Not much is known about the genome of ''Streptococcus salivarius'' other than its genome size is estimated to be 1800kb long.  Its genome is yet to be sequenced [http://jb.asm.org/cgi/content/abstract/185/2/683 [7]], but it is in progress.  A closely related species of ''S. salivarius, S. thermophilus'' has been sequenced.  Its genome size has been determined to be 1796kb on a single circular chromosome [http://www.nature.com/nbt/journal/v22/n12/full/nbt1034.html [8]].  ''S. thermophilus'' is a lactic acid bacterium used for making milk and yogurt in the dairy industry.  It was important to sequence ''S. thermopilus'' because it is phylogenetically close to pathogenic streptococci.  The genome was sequenced using random shotgun sequencing and followed up by  multiplex PCR [http://www.nature.com/nbt/journal/v22/n12/full/nbt1034.html [8]].
 
 
 
''S. thermophilus'' has a 39% G-C content, 6 Ribosomal RNA's, and 67 tRNA's [http://www.nature.com/nbt/journal/v22/n12/full/nbt1034.html[8]].  It is also known that 10% of the genes are not functional due to frameshifts, nonsense mutations, deletions, or pseudogenes.  Frameshifts can occur in a genome when one or two nucleotides are deleted or inserted next to each other.  This would cause a shift in the reading frame, the frame in which DNA gets transcribed into RNA.  A pseudogene is a gene where it becomes transcribed and translated but it has no functional capabilities.  Moreover, 30% of their genome is dedicated to energy metabolism and 60% to atypical, phages, and transposons [http://www.nature.com/nbt/journal/v22/n12/full/nbt1034.html [8]].  Transposons are given the name "jumping genes" or mobile genetic elements because of their ability to move around in the genome.  They may cause mutation and they may increase the amount of DNA in the genome.
 
 
 
==Cell structure and metabolism==
 
 
 
''S. salivarius'' is a Gram-positive cocci, which means in a gram stain test it would stain purple.  Gram-positive bacteria have a single plasma membrane followed by periplasmic space and a thick peptidoglycan layer called murein. Other than protection the murein layer also helps in the shape and rigidity of the bacteria. Murein is a polymer which is unique to bacteria, this is the reason why it is a good target for antibiotics.  Moreover, the murein layer allows the bacteria to survive in media with osmotic pressure less than that of their cytoplasm [10].  ''S. salivarius'' is  approximately 2 µm in length.  The cocci usually occur in pairs and short chains.  They are facultative anaerobes and either non- or alpha hemolytic on blood agar [http://www.phac-aspc.gc.ca/msds-ftss/msds149e.html [5]].  Blood agar is used in labs to detect hemolytic activity.
 
 
 
''S. salivarius'' contains fimbriae on their cell surface.  Fimbriae are hair-like appendages that are composed of protein subunits with diameters ranging from 2-8 nm.  Fimbriae are involved in co-aggregation of ''S. salivarius'' with the periodontopathogen ''Prevotella intermeida ''[http://mic.sgmjournals.org/cgi/content/full/150/1/189?view=long&pmid=14702412 [2]].
 
 
 
==Ecology==
 
 
 
The hydrolysis of urea by urease enzymes of oral bacteria like ''Streptococcus salivarius'' has a major impact on oral microbial ecology and is involved in oral health and diseases. The ability to genetically engineer plaque bacteria that can modulate environmental pH through ureolysis will open the way to using ''S. salivarius'' to test hypotheses regarding the role of oral ureolysis in dental caries, calculus formation, and periodontal diseases. This organism may eventually prove useful for controlling dental caries by replacement therapy [http://iai.asm.org/cgi/content/abstract/64/2/585 [1]].
 
 
 
==Pathology==
 
 
 
Diseases may be caused if ''S. salivarius'' enters the blood stream.  This may occur during dental work or brushing of the teeth.  ''S. salivarius'' may cause septicemia in neutropenic patients.  Septicemia is a systemic disease caused by pathogenic organisms or their toxins in the blood stream, it is also known simply as blood poisoning.
 
 
 
''Streptococcuss salivarius'' is infrequently pathogenic.  Viridans streptococci species cause most dental caries and are the most frequent cause of subacute native valve bacterial endocarditis, typically associated with dental procedures [http://jb.asm.org/cgi/reprint/51/6/717 [9]].  Endocaritis is an inflammation of the inner layer of the heart, the endocardium.  The severity of the disease is typically based on the microorgansim involved.  In the case of Streptococci the disease is labeled as subacute bacterial endocarditis, which is due to the bacterias low virulence, but in the case of the acute bacterial endocarditis it is caused by ''Staphylococcus aureus'' which has a much greater virulence [http://jb.asm.org/cgi/reprint/51/6/717 [9]].
 
 
 
==Application to Biotechnology==
 
 
 
''Streptococcus salivarius'' secretes a glucosltransferase (Gtf) which forms a glucan from sucrose.  ''S. salivarius'' is one of the main sources of Gtf in saliva and in the acquired pellicle is believed to be from ''S. salivarius'' resident on the dorsum of the tongue. Gtfs incorporated in the pellicle are known to be active and to form glucans to which other oral streptococci, such as the mutans streptococci, are able to adhere. Thus, Gtfs produced by ''S. salivarius'' at sites distant from the tooth surface may aid in the initial attachment or entrapment of other oral species on newly erupted tooth surfaces or on tooth surfaces following prophylaxis. [http://iai.asm.org/cgi/content/abstract/63/2/609 [4]]
 
 
 
''S. salivarius'' is also known to secrete an enzyme called urease.  Urease can catalyze the hydrolysis of urea to ammonia and carbon dioxide [http://iai.asm.org/cgi/content/abstract/64/2/585 [1]].
 
 
 
==Current Research==
 
 
 
A new research found results that suggest Gram-positive micro-organisms such as ''S. salivarius'' contribute to oral malodor production by deglycosylating salivary glycoproteins, thus exposing their protein core to further degradation by Gram-negative micro-organisms.  Studies show a direct link between levels of ''Streptococcus salivarius'' in the mouth, throat and tonsils and the development of halitosis [http://jdr.iadrjournals.org/cgi/content/abstract/85/10/910 [3]].  Current research is being done to better understand mouth odor in relation to ''S. salivarius''.
 
 
 
Also as mentioned previously in the Ecology section, further studies are being performed to be able to prevent dental caries.
 
 
 
==References==
 
 
 
[http://iai.asm.org/cgi/content/abstract/64/2/585 [1]] Chen, YY. "Streptococcus salivarius urease: genetic and biochemical characterization and expression in a dental plaque streptococcus." Infection and Immunity.1996.Volume 64 No.2. p. 585-592.
 
 
 
[http://mic.sgmjournals.org/cgi/content/full/150/1/189?view=long&pmid=14702412 [2]] Lévesque, Céline, ChristianVadeboncoeur, and MichelFrenette. "The csp operon of Streptococcus salivarius encodes two predicted cell-surface proteins, one of which, CspB, is associated with the fimbriae". Microbiology 150.2004. (Pt 1). p. 189-98.
 
 
 
[http://jdr.iadrjournals.org/cgi/content/abstract/85/10/910 [3]] N. Sterer1, and M. Rosenberg "Streptococcus salivarius Promotes Mucin Putrefaction and Malodor Production by Porphyromonas gingivalis".2006.Journal of Dental Reserach. p. 910-914.
 
 
 
[http://iai.asm.org/cgi/content/abstract/63/2/609 [4]] Simpson, CL. "Streptococcus salivarius ATCC 25975 Possesses at Least Two
 
Genes Coding for Primer-Independent Glucosyltransferases".Infection and Immunity.1995.Volume 63 No.2. p. 609-621.
 
 
 
[http://www.phac-aspc.gc.ca/msds-ftss/msds149e.html [5]] "MATERIAL SAFETY DATA SHEET - INFECTIOUS SUBSTANCES". "Public Health Agency of Canada". 2001.
 
 
 
[http://www.cns.fr/externe/English/Projets/Projet_MB/organisme_MB.html [6]] Streptococcus salivarius JIM8777, JIM8780: The principal inhabitant of the human oral cavity. Genoscope - Centre National de Séquençage. http://www.cns.fr/externe/English/Projets/Projet_MB/organisme_MB.html.
 
 
 
[http://jb.asm.org/cgi/content/abstract/185/2/683 [7]] Chastanet, A. "clpP of Streptococcus salivarius Is a Novel Member of the Dually Regulated Class of Stress Response Genes in Gram-Positive Bacteria." Journal of bacteriology.2003.Volume 185 No.2. p.683-687.
 
 
 
[http://www.nature.com/nbt/journal/v22/n12/full/nbt1034.html [8]] Bolotin, A "Complete sequence and comparative genome analysis of the dairy bacterium Streptococcus thermophilus". Nature biotechnology.2004.Volume 22 No. 12. p. 1554-1558.
 
 
 
[http://jb.asm.org/cgi/reprint/51/6/717 [9]] White, J C, and C FNiven. "Streptococcus s.b.e.: A Streptococcus Associated with Subacute Bacterial Endocarditis." Journal of bacteriology.1946. Volume 51 No. 6. p. 717-22.
 
 
 
[10] Schaechter, M, Ingraham, L. J, Neidhardt,C. F."Microbe". Washington: ASM Press, 2006. p.23-25
 
 
 
Edited by Artin Meserkhani, a student of [mailto:ralarsen@ucsd.edu Rachel Larsen] and Kit Pogliano
 
 
 
KMG
 

Revision as of 20:36, 10 December 2017

This student page has not been curated.

1. Classification

a. Higher order taxa

Domain; Phylum; Class; Order; Family; Genus Include this section if your Wiki page focuses on a specific taxon/group of organisms

2. Description and significance

Describe the appearance, habitat, etc. of the organism, and why you think it is important.

  • Include as many headings as are relevant to your microbe. Consider using the headings below, as they will allow readers to quickly locate specific information of major interest*

3. Genome structure

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?

4. Cell structure

Interesting features of cell structure. Can be combined with “metabolic processes”

5. Metabolic processes

Describe important sources of energy, electrons, and carbon (i.e. trophy) for the organism/organisms you are focusing on, as well as important molecules it/they synthesize(s).

6. Ecology

Habitat; symbiosis; contributions to the environment.

7. Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

7. Key microorganisms

Include this section if your Wiki page focuses on a microbial process, rather than a specific taxon/group of organisms

8. Current Research

Include information about how this microbe (or related microbes) are currently being studied and for what purpose

9. References

It is required that you add at least five primary research articles (in same format as the sample reference below) that corresponds to the info that you added to this page. [Sample reference] Faller, A., and Schleifer, K. "Modified Oxidase and Benzidine Tests for Separation of Staphylococci from Micrococci". Journal of Clinical Microbiology. 1981. Volume 13. p. 1031-1035.