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The formation of biofilm is of high importance to P. gingivalis as it enhances the transmission, but more importantly, the pathogenicity of the infective pathogen strain. It also aids in protecting the species from human immune responses and antibiotics. Dental plaque is a common form of biofilm of the teeth. The accumulation of microorganisms subjects the teeth and gingival tissues to high concentrations of bacterial metabolites which results in dental disease (REFERENCE Mihai et al. 2010). Formation and maintenance of the periodontal biofilms is associated with periodontal microflora interaction, which is mediated by outer membrane proteins (REFERENCE Bos et al., 2007). This means that patients with periodontitis will produce higher levels of cytokines, including Interleukin (IL-), 1β and 6 as a response to the biofilm periodontitis infection through the T helper cells (REFERENCE Gonzales et al., 2014). | The formation of biofilm is of high importance to P. gingivalis as it enhances the transmission, but more importantly, the pathogenicity of the infective pathogen strain. It also aids in protecting the species from human immune responses and antibiotics. Dental plaque is a common form of biofilm of the teeth. The accumulation of microorganisms subjects the teeth and gingival tissues to high concentrations of bacterial metabolites which results in dental disease (REFERENCE Mihai et al. 2010). Formation and maintenance of the periodontal biofilms is associated with periodontal microflora interaction, which is mediated by outer membrane proteins (REFERENCE Bos et al., 2007). This means that patients with periodontitis will produce higher levels of cytokines, including Interleukin (IL-), 1β and 6 as a response to the biofilm periodontitis infection through the T helper cells (REFERENCE Gonzales et al., 2014). | ||
Porphyromonas species are non-motile bacterium, however not all bacteriodetes share this quality. A study conducted by Nakayama K. in 2014 showed that Porphyromonas species, including P. gingivalis and other bacteriodetes, contain the type IV secretion system (T9SS). T9SS in gram-negative bacterial organisms has been linked to gliding motility, as the bacterium is motile but there is no motility components (eg. flagella or type IV pili), that are influencing the motility (REFERENCE Nakayama 2014). This leads to the postulation that since the phylum bacteriodetes all share origin and all contain T9SS, that genetic adaptation and mutation may occur making Porphyromonas gingivalis and other bacterium motile. | Porphyromonas species are non-motile bacterium, however not all bacteriodetes share this quality. A study conducted by Nakayama K. in 2014 showed that Porphyromonas species, including P. gingivalis and other bacteriodetes, contain the type IV secretion system (T9SS). T9SS in gram-negative bacterial organisms has been linked to gliding motility, as the bacterium is motile but there is no motility components (eg. flagella or type IV pili), that are influencing the motility (REFERENCE Nakayama 2014). This leads to the postulation that since the phylum bacteriodetes all share origin and all contain T9SS, that genetic adaptation and mutation may occur making Porphyromonas gingivalis and other bacterium motile. | ||
P. gingivalis utilises iron in the form of heme transported from hemin through ABC Transporters. Outer membrane receptors, proteases (eg. gingipains) and lipoproteins are used to collect iron/heme as P. gingivalis doesn’t produce siderophores. Proteolytic activities of gingipan R and K assist in maturation of various cell surface proteins (eg. fimA fimbrilin major fimbriae, 75-kDa protein subunit minor fimbriae, hemagglutinins and haemoglobin receptor proteins), (REFERENCE Kadawaki et al. 2000). | P. gingivalis utilises iron in the form of heme transported from hemin through ABC Transporters. Outer membrane receptors, proteases (eg. gingipains) and lipoproteins are used to collect iron/heme as P. gingivalis doesn’t produce siderophores. Proteolytic activities of gingipan R and K assist in maturation of various cell surface proteins (eg. fimA fimbrilin major fimbriae, 75-kDa protein subunit minor fimbriae, hemagglutinins and haemoglobin receptor proteins), (REFERENCE Kadawaki et al. 2000). Porphyromonas gingivalis also lives in metabolic symbioses with Treponema denticola, both exhibit symbiosis in growth and synergistic virulence upon co-infection (REFERENCE Tan et al 2014). | ||
==Ecology== | ==Ecology== | ||
Revision as of 08:41, 23 September 2016
Porphyromonas gingivalis and Porphyromonas endodontalis Taylor Veltmeyer Bench C 22/09/2016 [1]
Classification
Higher order taxa
Kingdom: Bacteria Phylum: Bacteroidetes Class: Bacteroidetes Order: Bacteroidales Family: Porphyromonadaceae Genus: Porphyromonas
Species
Porphyromonas gingivalis Type Strain: strain 2561 = ATCC 33277= CCUG 25893 = CCUG 25928 = CIP 103683 = DSM 20709 = JCM 12257 = NCTC 11834. Sequence accession no. (16S rRNA gene) for the type strain: AB035459. Basonym: Bacteroides gingivalis Coykendall et al. 1980.
Porphyromonas endodontalis Type strain: strain HG370 = ATCC 35406= JCM 8526 = NCTC 13058. Sequence accession no. (16S rRNA gene) for the type strain: AY253728. Basonym: Bacteroides endodontalis van Steenbergen et al. 1984.
Description and significance
Porphyromonas gingivalis and Porphyromonas endodontalis are two species that belong to the phylum Bacteriodetes. For the purpose of this study, the main focus will be Porphyromonas gingivalis as both species have very similar attributes, however P. gingivalis is the most prevalent and primary cause of disease, P. endodontalis is an associated organism involved in the disease and differences amongst the two will be mentioned in detail. Porphyromonas gingivalis is a Gram-negative anaerobic bacterium, that is non-motile and rod-shaped and is also the major etiological causative agent of chronic periodontitis. P. gingivalis is commonly found in the oral cavity and implicated in certain forms of periodontal disease. Also found in upper gastrointestinal tract, respiratory tract and colon. It has also been isolated from women with bacterial vaginosis. P. endodontalis is commonly found in infected dental root canals and submucous abscesses of endodontal origin. It is also occasionally found on oral mucous membranes and periodontal pockets. Genome was first sequenced and cultured by the American Type Culture Collection (ATCC), and it is important as P. gingivalis is not only isolated to the oral cavity/mouth. Both strains of Porphyromonas have been cultured in lab and both produce black-pigmented bacteria, however culturing is not the best way of identifying the species, Polymerase Chain Reaction produces a higher frequency of species production. The importance of studying disesease associated with P. gingivalis is that according to the World Health Organisation (WHO), periodontal disease affects 10-15% of the adult population worldwide [2]
Genome structure
The genome of P. gingivalis has been described in 2003 and revealed 1,990 open reading frames (i.e. protein-coding sequences), encoded by 2,343,479 bp, with an average G+C content of 48.3%. An estimated 463 genes are essential
Cell structure and metabolism
The cell wall struture for P. gingivalis is similar to that of other gram-negative bacteria. It has a thin peptidoglycan layer in the periplasmic layer between the inner and outer lipid membranes. The cell wall comprises of two cell membranes, the inner membrane and the outer membrane and both have different composition. The inner membrane is a phospholipid bilayer that contains numerous integral inner membrane proteins (REFERENCEBos et al., 2007), whilst the outer membrane is an asymmetrical bilayer, meaning it consists of phospholipids and lipopolysaccharides in the inner and outer leaflets, respectively. The cell membrane is also a selective barrier used to protect and facilitate ,movement of specific substances through outer membrane porins (REFERENCE Nikaido, 2003). The formation of biofilm is of high importance to P. gingivalis as it enhances the transmission, but more importantly, the pathogenicity of the infective pathogen strain. It also aids in protecting the species from human immune responses and antibiotics. Dental plaque is a common form of biofilm of the teeth. The accumulation of microorganisms subjects the teeth and gingival tissues to high concentrations of bacterial metabolites which results in dental disease (REFERENCE Mihai et al. 2010). Formation and maintenance of the periodontal biofilms is associated with periodontal microflora interaction, which is mediated by outer membrane proteins (REFERENCE Bos et al., 2007). This means that patients with periodontitis will produce higher levels of cytokines, including Interleukin (IL-), 1β and 6 as a response to the biofilm periodontitis infection through the T helper cells (REFERENCE Gonzales et al., 2014). Porphyromonas species are non-motile bacterium, however not all bacteriodetes share this quality. A study conducted by Nakayama K. in 2014 showed that Porphyromonas species, including P. gingivalis and other bacteriodetes, contain the type IV secretion system (T9SS). T9SS in gram-negative bacterial organisms has been linked to gliding motility, as the bacterium is motile but there is no motility components (eg. flagella or type IV pili), that are influencing the motility (REFERENCE Nakayama 2014). This leads to the postulation that since the phylum bacteriodetes all share origin and all contain T9SS, that genetic adaptation and mutation may occur making Porphyromonas gingivalis and other bacterium motile. P. gingivalis utilises iron in the form of heme transported from hemin through ABC Transporters. Outer membrane receptors, proteases (eg. gingipains) and lipoproteins are used to collect iron/heme as P. gingivalis doesn’t produce siderophores. Proteolytic activities of gingipan R and K assist in maturation of various cell surface proteins (eg. fimA fimbrilin major fimbriae, 75-kDa protein subunit minor fimbriae, hemagglutinins and haemoglobin receptor proteins), (REFERENCE Kadawaki et al. 2000). Porphyromonas gingivalis also lives in metabolic symbioses with Treponema denticola, both exhibit symbiosis in growth and synergistic virulence upon co-infection (REFERENCE Tan et al 2014).
Ecology
Aerobe/anaerobe, habitat (location in the oral cavity, potential other environments) and microbe/host interactions.
Pathology
Do these microorganisms cause disease in the oral cavity or elsewhere?
Application to biotechnology
Bioengineering, biotechnologically relevant enzyme/compound production, drug targets,…
Current research
Summarise some of the most recent discoveries regarding this species.
References
Chockalingam, Evvie, and S. Subramanian. “Utility of Eucalyptus Tereticornis (Smith) Bark and Desulfotomaculum Nigrificans for the Remediation of Acid Mine Drainage.” Bioresource Technology 100, no. 2 (January 2009): 615–621. doi:10.1016/j.biortech.2008.07.004.
“Genus Desulfotomaculum - Hierarchy - The Taxonomicon.” Accessed November 5, 2013. http://taxonomicon.taxonomy.nl/TaxonTree.aspx?id=229.
Kaksonen, Anna H., Stefan Spring, Peter Schumann, Reiner M. Kroppenstedt, and Jaakko A. Puhakka. “Desulfotomaculum Thermosubterraneum Sp. Nov., a Thermophilic Sulfate-reducer Isolated from an Underground Mine Located in a Geothermally Active Area.” International Journal of Systematic and Evolutionary Microbiology 56, no. 11 (November 1, 2006): 2603–2608. doi:10.1099/ijs.0.64439-0.
Liu, Yitai, Tim M. Karnauchow, Ken F. Jarrell, David L. Balkwill, Gwendolyn R. Drake, David Ringelberg, Ronald Clarno, and David R. Boone. “Description of Two New Thermophilic Desulfotomaculum Spp., Desulfotomaculum Putei Sp. Nov., from a Deep Terrestrial Subsurface, and Desulfotomaculum Luciae Sp. Nov., from a Hot Spring.” International Journal of Systematic Bacteriology 47, no. 3 (July 1, 1997): 615–621. doi:10.1099/00207713-47-3-615.
Moser, Duane P, Thomas M Gihring, Fred J Brockman, James K Fredrickson, David L Balkwill, Michael E Dollhopf, Barbara Sherwood Lollar, et al. “Desulfotomaculum and Methanobacterium Spp. Dominate a 4- to 5-kilometer-deep Fault.” Applied and Environmental Microbiology 71, no. 12 (December 2005): 8773–8783. doi:10.1128/AEM.71.12.8773-8783.2005.
Ogg, Christopher D, and Bharat K C Patel. “Desulfotomaculum Varum Sp. Nov., a Moderately Thermophilic Sulfate-reducing Bacterium Isolated from a Microbial Mat Colonizing a Great Artesian Basin Bore Well Runoff Channel.” 3 Biotech 1, no. 3 (October 2011): 139–149. doi:10.1007/s13205-011-0017-5.
Pikuta, E, A Lysenko, N Suzina, G Osipov, B Kuznetsov, T Tourova, V Akimenko, and K Laurinavichius. “Desulfotomaculum Alkaliphilum Sp. Nov., a New Alkaliphilic, Moderately Thermophilic, Sulfate-reducing Bacterium.” International Journal of Systematic and Evolutionary Microbiology 50 Pt 1 (January 2000): 25–33.
This page is written by Taylor Veltmeyer, 42057273 for the MICR3004 course, Semester 2, 2016
