Porphyromonas endodontalis
Classification
Bacteria (Kingdom); Bacteroidetes (Phylum); Bacteroidetes (Class); Bacteroidales(Order); Porphyromonadaceae (Family); Porphyromonas (Genus)
Genus Species
Porphyromonas endodontalis
Description and Significance
Give a brief description of the microorganism and explain why you think it is important. How does it relate to the other organisms in its phylum (bacteria and fungi) or group (archaea, virus, protist). Use the following for each reference in text (change number accordingly)--> [1]
Porphyromonas endodontalis is a black pigmented gram-negative microbe associated with endodontic infections, gingivitis and tooth pulp necrosis. Unlike P. Gingivalis, P. endodontalis is not native to the oral cavity. [1]
Unlike other members of the genus, P. endodontalis have shown optimum growth in culture around 37 degrees Celsius. It also differs from other members of the Genus in that a major product of the bacteria is succinate. All three bacteria of the genus Porphyromonas produce butyrate, but only P. endodontalis produces succinate. [2]
Structure, Metabolism, and Life Cycle
Interesting features of its structure; how it gains energy (how it replicates, if virus); what important molecules it produces (if any), does it have an interesting life cycle?
Porphyromonas endodontalis are anaerobic, black pigmented, nonsporeforming, nonmotile rods that utilize nitrogeneous substrates as energy sources. [2] The black pigment is observed in colonies after 7 to 14 days. The major pigment associated to the dark color is protoheme, although protoporphyrin is also associated to the color. Much like other gram-negative bacteria, prophyromonas endodontalis have a cell wall made of peptidoglycan but has a high concentration of lysine. [2]
The major products of fermentation are n-butyric and acetic acids as well as lower levels of propionic , isobutyric, and isovaleric acids.
Ecology and Pathogenesis
Natural habitat (soil, water, commensal of humans or animals?)
If relevant, how does this organism cause disease? Human, animal, or plant hosts? Important virulence factors, as well as patient symptoms.
Porphyromonas endodontalis forms black colonies on gingival epitheal cells. The colonization of this microbe causes periapical lesions with acute symptoms such as pain, swelling, and suppuration. [3] Studies have shown that P. endodontalis is mainly found in symptomatic oral infections but can also be found in asymptomatic infections. It is suggested that P. endodontalis causes infections by releasing outer membrane blebs which may contain a lipopolysaccharide. [4] The mechanism of how P. endodontalis adheres to gingival epithelial cells is different from related bacteria and a current subject of research.
References
[1] Cao, H. H., Qi, Z. Z., Jiang, H. H., Zhao, J. J., Liu, Z. Z., & Tang, Z. Z. (2012). Detection of Porphyromonas endodontalis, Porphyromonas gingivalis and Prevotella intermedia in primary endodontic infections in a Chinese population. International Endodontic Journal, 45(8), 773-781. doi:10.1111/j.1365-2591.2012.02035.x
[2] Shah HN, Collins MD. Proposal for reclassification of Bacteroides asaccharolyticus, Bacteroides gingivalis, and Bacteroides endodontalis in a new genus, Porphyromonas. Int J Syst Bacteriol 1988; 38: 128–31.
[3] Asao, K. (2002). Pathogenic factors of porphyromonas endodontalis. Dental Journal of Iwate Medical University, 27(3), 187-196. Retrieved from http://sciencelinks.jp/j-east/article/200306/000020030603A0068704.php
[4] Kaapasalo, M. (2006). Bacteroides spp. in dental root canal infections. Dental Traumatology, 5(1), 1-10. Retrieved from http://onlinelibrary.wiley.com/doi/10.1111/j.1600-9657.1989.tb00330.x/abstract
Author
Page authored by Isaac Colden, student of Mandy Brosnahan, Instructor at the University of Minnesota-Twin Cities, MICB 3301/3303: Biology of Microorganisms.
