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Louise Parker Bench D 31/08/2016

Classification

Higher order taxa

Bacteria – Domain – Bacteroidetes – Bacteroidetes – Bacteroidales – Porphyromonadaceae – Porphyromonas

Species

Species: Porphyromonas gingivalis
Strain: strain 2561 = ATCC 33277= CCUG 25893 = CCUG 25928 = CIP 103683 = DSM 20709 = JCM 12257 = NCTC 11834. 

Description and significance

Porphyromonas gingivalis is a Gram-negative anaerobe. It is a major causative agent of the initiation and progression of periodontal disease, a main cause of tooth loss ^[1]. P. gingivalis is an opportunistic pathogen found in the subgingival sulcus of the human oral cavity ^[2]. Along with T. denticola and T. forsythia, P. gingivalis forms the red bacterial complex which is often seen in advanced periodontal lesions (^[2]. P. gingivalis is strongly associated with gingival recession, increased sulcular pocket depth and bleeding upon probing (Molecular analysis of bacteria in periodontitis: evaluation of clone libraries, novel phylotypes and putative pathogens). The bacterium has also been found in healthy individuals, at a prevalence of 10-25%. P. gingivalis is found in those with periodontitis at a prevalence of 79%-90%. Epidemiological studies have shown that strains vary in association with human disease and virulence in animal models. Strains W83, W50, ATCC 49417, A7A1 have been classified as virulence, whereas avirulent strains include 381, 33277 and 23A4 ^[4].
P. gingivalis is obligately anaerobic and does not form spores ^[5]. Cells are non-motile rods 0.5 by 1-2um in broth ^[5]. On blood agar, colonies are black-pigmented smooth, shiny, convex and 1-2mm in diameter ^[5].

Genome structure

Select a strain for which genome information (e.g. size, plasmids, distinct genes, etc.) is available.

The Porphyromonas gingivalis strain W83 has a 2,343,479bp genome sequence. It has an average G+C content of 48.3%. 1,990 open reading frames were identified in the genome, making up 85% of the genome. 1,075 of these were assigned biological role categories. - (Complete Genome Sequence of the Oral Pathogenic Bacterium Porphyromonas gingivalis Strain W83)Distinct genes

Cell structure and metabolism

Cell wall, biofilm formation, motility, metabolic functions.

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

1. Naito, M., Hirakawa, H., Yamashita, A., Ohara, N., Shoji, M., Yuritake, H., Nakayama, K., Toh, H., Yoshimura, F., Kuhara, S., Hattori, M., Hayashi, T. and Nakayama, K. (2008) Determination of the Genome Sequence of Porphyromonas gingivalis Strain ATCC 33277 and Genomic Comparison with Strain W83 Revealed Extensive Genome Rearrangements in P. gingivalis. DNA Res 4:215-225.

2. How, K. Y., Song, K. P. and Chan, K. G. (2016) Porphyromonas gingivalis: An Overview of Periodontopathic Pathogen below the Gum Line. Front Microbiol, 7: 53.

3. Hutter G., Schlagenhauf, U., Valenza, G., Horn, M., Burgemeister, S., Claus, H. and Vogel, U. (2003) Molecular analysis of bacteria in periodontitis: evaluation of clone libraries, novel phylotypes and putative pathogens. Microbiology 149: 67-75.

4. Igboin, C. O., Griffen, A. L. and Leys, E. J. (2009) Porphyromonas gingivalis strain diversity. J Clin Microbiol, 47,: 3073-81.

5. Shah N, H., Collins D, M. (1988) Proposal for Reclassification of Bacteroides asaccharolyticus, Bacteroides gingivalis, and Bacteroides endodontalis in a New Genus, Porphyromonas. Int J Syst Evol Microbiol 38 :128-131.

6. Farquharson, D., Butcher, J. P., and Culshaw, S. (2012) Periodontitis, Porphyromonas, and the pathogenesis of rheumatoid arthritis. Mucosal Immunol 5:112-20

This page is written by Louise Parker for the MICR3004 course, Semester 2, 2016