Difference between revisions of "Prevotella oralis"
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Latest revision as of 12:51, 20 October 2017
Higher order taxa
Bacteria; Bacteroidetes/Chlorobi group; Bacteroidetes (class); Bacteroidales; Prevotellaceae; Prevotella
Prevotella oris Type strain: ATCC 33573= CCUG 15405 = CIP 104480 = JCM 8540 = JCM 12252 = NCTC 13071 = VPI D1A-1A.
Description and significance
Prevotella oris is a gram negative, rod shaped bacterium which was first discovered in 1982 by Holdeman et al. , and initially named Bacteroides oris. It was later subdivided into a new genus named Prevotella by Shah and Collins in 1990 . It is an obligate anaerobic, non-motile, non-spore forming and non-pigmenting organisms that has mostly been found in gingival crevices of the human mouth. It has been shown to grow within biofilms as part of a healthy oral fauna in humans, but is also capable of being a facultative pathogen. The organisms has been found in patients with periodontitis, caries as well as various sites of human infections . In individual cases Prevotella oris has been identified to have been the cause of bacteraemia , and may be associated with early rheumatoid arthritis , hence why it is a medically significant species.
Prevotella oris was sequenced using the DSM 18711 = JCM 12252 strain in the Prevotella oris DSM 18711 = JCM 12252 whole genome shotgun project by Centre for Omics and Bioinformatics, Graduate School of Frontier Sciences, University of Tokyo in 2012 . The genome has a median length of 3.16482 Mb, a median protein count of 2502 and a median GC percentage of 43.8%. Out of the total number of genes, 1939 have been identified to be coding genes, 4 RNA genes, 2 complete rRNA genes and 654 pseudo genes . Some strains of this bacterium have shown penicillin resistance, which correlates to the encoding of a beta lactamase . In clinical isolates this antibiotic resistance has increased fourfold between 2007 and 2009.
Cell structure and metabolism
Since this non-motile organism is an obligate anaerobe, it thrives in gingival pockets within the human mouth, as well as in biofilms established by other microbes. It encodes for malate dehydrogenase and glutamate dehydrogenase, which allows it to ferment dextrin, fructose, glucose, lactose, maltose, mannose, raffinose, starch, starch and sucrose . It requires hemin and menadione for growth , and is incapable of reducing nitrate. Different strains have surfaced with resistance to amoxicillin and ceftriaxone antibiotics. In addition, cultured P. oris strains produced an immunoglobulin A protease, hyaluronidase and beta-lactamase enzymes .
Prevotella oris mainly inhabits anaerobic pockets, e.g. gingival sulci and periodontal pockets, and biofilms within the oral cavity of humans, where there are protected from immune cells like macrophages . It has been isolated from the upper respiratory tract as well as the urogenital tract, and appears to be present in high abundance in pus and wound fluid drainage from oral abscesses . Holdeman et al. initially thought to have identified P. oris in the intestines of chicken and ruminants, which later turned out to be different species of Prevotella. P. oris is moderately fermentative, grows best in slightly acidic environments and is sensitive to bile salts .
Albeit being present in most oral infections and abscesses , Prevotella oris has not been shown to be the cause of any of primary infections. Rather it appears to be an opportunistic pathogen, which once it reaches the blood stream, thrives in anaerobic environments and causes bacteraemia and sepsis in ICU patients , and exacerbating inflammation and infections in isolated cases . Due to its ability to produce hemolysin, it is able to lyse human, horse, sheep and rabbit red blood cells and damage host tissues , adding to inflammatory reactions within host environments.
Application to biotechnology
There are no current reports of biotechnological applications of P. oris. Based on the emergence of associations of diseases and oral microbes, genetic detection of P. oris may aid to develop diagnostic tools and identification of at risk populations for certain diseases like early rheumatoid arthritis.
Current research is being undertaken on receptors against hemolysin produced by P. oris, which is a potential source of cytotoxicity in oral as well as systemic infections . The production of hemolysin as a virulence factor is essential for P. oris due to its dependence on iron for cellular growth.
1. Holdeman LV, Moore WEC, Churn PJ, Johnson JL. 1982. Bacteroides oris and Bacteroides buccae, new species from human periodontitis and other human infections. International Journal of Systematic Bacteriology 32:125-131.
2. Shah HN, Collins DM. 1990. NOTES: Prevotella, a New Genus To Include Bacteroides melaninogenicus and Related Species Formerly Classified in the Genus Bacteroides. International Journal of Systematic and Evolutionary Microbiology 40:205-208.
4. Wolff B, Boutin, S., Lorenz, H. M., Ueffing, H., Dalpke, A., Wolff, D. . 2017. Prevotella and Alloprevotella species characterize the oral microbiome of early rheumatoid arthritis. Scientific Abstracts FRI0698.
6. Boyanova L, Kolarov R, Gergova G, Dimitrova L, Mitov I. 2010. Trends in antibiotic resistance in Prevotella species from patients of the University Hospital of Maxillofacial Surgery, Sofia, Bulgaria, in 2003–2009. Anaerobe 16:489-492.
7. Cortés-Acha B, Figueiredo R, Seminago R, Roig FJ, Llorens C, Valmaseda-Castellón E. 2017. Microbiota Analysis of Biofilms on Experimental Abutments Mimicking Dental Implants: An in Vivo Model. Journal of periodontology doi:10.1902/jop.2017.170051:1.
10. Frat J-P, Godet C, Grollier G, Blanc J-L, Robert R. 2004. Cervical spinal epidural abscess and meningitis due to Prevotella oris and Peptostreptococcus micros after retropharyngeal surgery. Intensive Care Medicine 30:1695-1695.
This page is written by C. Angelina Schweikert for the MICR3004 course, Semester 2, 2017