Rickettsia typhi
Genus larsen From MicrobeWiki, the student-edited microbiology resource Jump to: navigation, search A Microbial Biorealm page on the genus Genus larsen
Contents [hide] 1 Classification 1.1 Higher order taxa 1.2 Species 2 Description and significance 3 Genome structure 4 Cell structure and metabolism 5 Ecology 6 Pathology 7 Application to Biotechnology 8 Current Research 9 References
Classification
Higher order taxa
Domain:Bacteria Phylum: Proteobacteria Class: Rickettsiales Order: Rickettsiales Family: Rickettsiaceae
Species
NCBI: Taxonomy
Rickettsia typhi
Description and significance
Rickettsia typhi is a small Gram negative rod bacteria. Therefore, it has an outer membrane and a thin murein layer. Lipopolysaccharides which are unique to bacteria can be found on it’s outer membrane. Rickettsia typhi is the cause of murine typhus, a terrible disease. Infection causes headache, fever, and leads to multisystem disease, including infection of the brain, lung, liver, kidney and heart.
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.
Genome structure
The complete genome sequence of R. typhi is 1,111,496 base pairs. There were 877 genes and 838 encode proteins and 24 were unique to R. typhi. The Guanine + Cytosine content in their DNA is 29-30% of it's DNA. R. typhi's genome size is 1080 Mdaltons.
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?
Cell structure and metabolism
Rickettsiae thrive in environments of high potassium, usually in the cytosol of eukaryotic cells. Membrane transport systems are used to acquire molecules such as ATP and amino acids from the host. However, they have and independent metabolism where they can produce their own ATP and proteins.
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
Ecology
Humans are affected by this because ticks can carry this bacteria. Although typhus can be found worldwide, it is mostly present in warm coastal areas. Typhus is uncommon in the United States. It is usually seen in areas where hygiene is poor. Murine typhus is transmitted by exposure to rat fleas or rat feces, or exposure to other infected animals in the environment.
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Pathology
Rickettsia typhi can be transmitted to host by the bite of an infected flea or through the feces of the carrier. In the endothelium is where the microbe divides and transmits itself through feces of the infected. The microbe accumulates after binary fission then the host cell bursts releasing many rickettsia. Destruction of the endothelial cell causes damaged tissue, organs, and loss of blood. Antimicrobial agents are made to enter the host cells and aid in decreasing the effects or R. typhi. Some medications made are doxycycline, tetracycline and chloramphenicol. Developments of insecticides and rat control are being made to decrease the probability of typhus occurring.
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
Rickettsiae cannot be cultivated on an artificial medium in the lab. They must be grown in other ways such as in animals or cell cultures.
Enter summaries of the most recent research here--at least three required
References
Schaechter, Moselio, and Medoff, Gerald, and Eisenstein, Barry. Mechanisms of Microbial Disease, Second Edition. Baltimore, Maryland: Williams & Wilkins, 1993
Schaechter, Moselio, and Engleberg, Cary, and Medoff, Gerald, and Eisenstein, Barry. Mechanisms of Microbial Disease, Third Edition. Baltimore, Maryland: Williams & Wilkins, 1998
Complete Genome Sequence of Rickettsia typhi and Comparison with Sequences of Other Rickettsiae. 6 April 2007 <http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=516817>
RICKETTSIA, CHLAMYDIA, MYCOPLASMA. 31 April 2007 <http://www.kcom.edu/faculty/chamberlain/Website/Lects/RICKETT.HTM>
[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.
Edited by Omar Mendoza student of Rachel Larsen and Kit Pogliano
Retrieved from "http://microbewiki.kenyon.edu/index.php/Genus_larsen"
