Porphyromonas gingivalis

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P. gingivalis colonies grown on blood agar.[1] Heme from the media is oxidized by the bacteria to produce hemin which accumulates on the cell surface producing a characteristic black pigment after about 7 days of anaerobic incubation.[2]

Ron Ramsay, Bench C, September 23, 2016 [3]

Classification

Higher order taxa

(domain) Bacteria — (phylum) Bacteroidetes — (class) Bacteroidia — (order) Bacteroidales — (family) Porphyromonadaceae — (genus) Porphyromonas [4][5]

Species

Porphyromonas gingivalis

Type strain: 2561 = ATCC 33277 = BCRC 14417 = CCRC 14417 = CCUG 25893 = CCUG 25928 = CIP 103683 = Coykendall 2561 = DSM 20709 = JCM 12257 = KCTC 5121 = NCTC 11834 = Slots 2561 [5][6]

Description and significance

Give a general description of the species (e.g. where/when was it first discovered, where is it commonly found, has it been cultured, functional role, type of bacterium [Gram+/-], morphology, etc.) and explain why it is important to study this microorganism.

Genome structure

Comparisons and overlap of essential genes and the core genome of P. gingivalis type strain ATCC 33227 together with the entire curated Database of Essential Genes[7]

The whole genome sequence of P. givivalis type strain ATCC 33227 was determined in 2008 by Naito et al.[8], deposited as Genbank accession AP009380.[9] The genome comprises a single circular chromosome is 2.35 million bp in size, averaging 48.4% G+C content, and is without a plasmid. Coding sequence coverage is 86.1%. The 2090 protein coding sequences identified have an average length of 970 bp.[8]

Mutagenesis experiments have identified 463 genes essential for in vitro viability for strain ATCC 33227, and of those, 424 are contained within its core genome of 1476 genes.[7]

According to the "mouse subcutaneous soft tissue abscess model", AATC 33227 is classified as a "less virulent" strain. [8] This property lends itself to comparative studies against the "more virulent" strains in order to identify their virulence factors. Naito et al. performed a genomic comparison analysis between the AATC 33227 and the "more virulent" W83 strain.[8] Both genomes contain 53 tRNA genes and 4 rRNA operons. Various types of mobile elements are present in both strains, including insertion sequences, miniature inverted-repeat transposable elements (MITEs) and conjugative transposons. Sequence alignment shows that extensive rearrangements have taken place between the two strains to produce strain-specific coding sequences (CDSs) 60% specific to ATCC 33277, 68% specific to W83. Gene similarities to other bacterial species such as Bacteroides fragilis suggests that horizontal transfers have taken place.

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

[2] [9]

  1. Nakayama, K. (2015). Porphyromonas Gingivalis and Related Bacteria: From Colonial Pigmentation to the Type Ix Secretion System and Gliding Motility. J Periodontal Res 50:1-8. doi:10.1111/jre.12255.
  2. 2.0 2.1 Shah, H. N. and M. D. Collins. (1988). Proposal for Reclassification of Bacteroides Asaccharolyticus, Bacteroides Gingivalis, and Bacteroides Endodontalis in a New Genus, Porphyromonas. Int J Syst Evol Microbiol 38:128-31. doi:10.1099/00207713-38-1-128.
  3. MICR3004: Microbial Genomics. University of Queensland. course information
  4. NCBI Taxonomy Browser
  5. 5.0 5.1 StrainInfo.net. Porphyromonas gingivalis
  6. LPSN: List of prokaryotic names with standing in nomenclature. Porphyromonas
  7. 7.0 7.1 Cite error: Invalid <ref> tag; no text was provided for refs named Klein
  8. 8.0 8.1 8.2 8.3 Cite error: Invalid <ref> tag; no text was provided for refs named Naito
  9. 9.0 9.1 Genbank nucleotide sequence database. accession: AP009380.1: "Porphyromonas gingivalis ATCC 33277 DNA, complete genome"

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This page is written by Ron Ramsay for the MICR3004 course, Semester 2, 2016