Shigella flexneri
UNDER CONSTRUCTION!!!
Classification
Gram-negative entero-invasive bacterium
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
Higher order taxa
Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacteriales; Enterobacteriaceae.
Strains: Shigella flexneri 1a. Shigella flexneri 1b. Shigella flexneri 2a. Shigella flexneri 2a strain 2457T. Shigella flexneri 2a strain 301. Shigella flexneri 3a. Shigella flexneri 3b. Shigella flexneri 5. Shigella flexneri 5 strain 8401. Shigella flexneri 5a. Shigella flexneri 6. Shigella flexneri Y.
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
Genus
Shigella flexneri
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
Description and significance
Shigella flexneri is important because it causes shigellosis, an acute bloody diarrhea. Shigella flexneri is the most common cause of the endemic form of Shigellosis, and the endemic form is the cause of most Shigellosis-related deaths. While not much of a problem in developed countries, Shigella flexneri (specifically Shigella flexneri 2a) is a major public health concern in developing countries.
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
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Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced. Describe how and where it was isolated. Include a picture or two (with sources) if you can find them.
Treponema denticola is a motile, slender, helically shaped flexible organism. It is made up of a periplasmic flagella wound around the helical protoplasmic cylinder and encased in an outer sheath. It's habitat is anaerobic and host-associated. It grows at an optimal temperature of 30-42°C, with a pH of 6.5-8.0. It is commonly found in the human oral cavity, specifically in subgingival dental plaque, and it is often associated with periodontal disease. Periodontal disease results in inflammation of the gum tissue, bone resorbtion, and subsequent tooth loss. Periodontal disease has now become a major concern in dentistry and 80% of adults in the USA are estimated to have had periodontal disease at some point in their lives. The complete genome of T. denticola strain 35405 was sequenced by using the random shotgun method described for genomes sequenced by The Institute for Genomic Research and it was designated as the type strain by Chan et al.
Edited by Neena Patel, student of Rachel Larsen at UCSD.
Genome structure
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
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Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?
Treponema denticola ATCC 35405 has a complete genome. It is made up of dsDNA and 1 chromosome. It is circular and the length is 2,843,201 nucleotides. The GC content is 37%. It has 2838 genes.
Replicon Type: chromosome.
Edited by Neena Patel, student of Rachel Larsen at UCSD.
Cell structure and metabolism
Lipopolysaccharide (LPS) is found on the surface of Shigella flexneri. It is the repeating sugar portion (O-antigen) of LPS that defines each serotype. This polysaccharide specificity can be used to target specific serotypes of Shigella.
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
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Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
The genome reveals factors mediating coaggregation, cell signaling, and stress protection. It has a spiral shape and is arranged in singles. It is a mobile organism but does not contain any endospores. Motility is by rapid rotation around the long axis, flexation of the cell and locomotion along a helical path. The most distinctive property is the presence of periplasmic flagella wound around the helical protoplasmic cylinder and encased in an outer sheath.
Edited by Neena Patel, student of Rachel Larsen at UCSD.
Ecology
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
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Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Pathology
Shigella flexneri causes an acute bloody diarrhea known as shigellosis or bacillary dysentery. The bleeding is due to destruction of the intestines. The bacteria destroy the intestinal epithelium, then continue to break down the intestinal mucosa. The condition can be fatal if not treated. It is not susceptible to dapsone, but it is susceptible to trimethoprim/sulfamethoxazole.
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
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Treponema denticola is a bacterial pathogen and plant plastid. It causes periodontal disease and gum inflammation.
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Edited by Neena Patel, student of Rachel Larsen at UCSD.
Application to Biotechnology
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
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Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
The suppressed immune systems of AIDS patients make them more vulnerable to diarrhea caused by Shigella flexneri. However, an intensive handwashing regimen can be used to lower the incidence of diarrhea.
Shigella flexneri 2a can be quickly detected from stool samples. The detection test involves a dipstick coated with monoclonal antibodies specific for Shigella flexneri 2a LPS, which includes a repeating, branched pentasaccharide.
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
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Enter summaries of the most recent research here--at least three required
References
[http://www.plosone.org/article/fetchArticle.action?articleURI=info:doi/10.1371/journal.pone.0000361 Nato, F., A. Phalipon, L. P. Nguyen, T. T. Diep, P. Sansonetti, and Y. Germani. 2007. "Dipstick for Rapid Diagnosis of Shigella flexneri 2a in Stool ." PLoS ONE, vol. 2, no. 4. (e361)]
example:
Edited by Roman Fajardo, student of Rachel Larsen and Kit Pogliano at UCSD.
