Higher order taxa
chlamydiae; chlamydiales; chlamydiaceae; chlamydia; chlamydia muridarum nigg
Description and significance
Chlamydia muridarum is included in a broad range of gram negative bacteria. It is rod shaped and lives in the cells of vertebrates, particularly mice and hamsters. It lives at an optimal host body temperature of 37 degrees Celcius and has a mesophilic range. Chlamydia muridarum was isolated in 1942 from the lungs of albino Swiss mice which all had similar symptoms. The MoPn strain was isolated in the mice and an SFPD strain of the same bacteria was isolated in hamsters. The chromosome and extrachromosomal plasmid of MoPn was sequenced and was discovered to bind a molecule known as mAbs which also binds to the bacteria Chlamydia trachomatis, which is the sexually transmitted disease seen in humans. The SFPD strain was also seen to bind mAbs. Thus it was important to sequence the Chlamydia muridarum genome to parallel its similarities with the human bacteria Chlamydia trachomatis.
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
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Chlamydia muridarum lives within the cells of infected mice and hamsters. It is known to cause pharyngitis, bronchitis, and pneumonitis. One way that the disease is thought to spread is by BAX dependent apoptosis. BAX plays a crucial role in regulating apoptosis. This BAX dependent apoptosis in turn releases Chlamydia containing apoptic cells from the infected cells which are then uptaken by uninfected cells, thus the disease begins a whole new cycle of infection and spreading.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
One such study concerning Chlamydia muridarum surrounded the fact that epithelial cells play an important part in host defense against microbial pathogens. A murine oviduct epithelial cell line was constructed to observed how epithelial cells conduct adaptive immune responses to Chlamydia muridarum infection. The infected epithelial cells produced a variety of chemokines such as CXCL16 and regulators of the acute-phase response including interleukin-1a and tumor necrosis factor alpha. The infected epithelial cells also expressed cytokines that augment gamma interferon production such as IL-12-p70. This is the first account of a non-myeloid/lymphoid cell making IL-12-p70 as a response to infection. The infected cells also began transforming growth factor alpha precursor expression which may lead to the pathological scarring seen from Chlamydia infections. Thus infected epithelium cells contribute greatly to the host's adaptive defenses but also contribute the immunopathology associated with Chlamydia infections.
Brunham RC, Shen C, Gill SR, Heidelberg JF, White O, Hickey EK, Peterson J, Utterback T, Berry K, Bass S, Linher K, Weidman J, Khouri H, Craven B, Bowman C, Dodson R, Gwinn M, Nelson W, DeBoy R, Kolonay J, McClarty G, Salzberg SL, Eisen J, Fraser CM.
"Chlamydia muridarum Nigg project at TIGR". 2000 Mar 15;28(6):1397-406. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=229 Perfettini, Jean-Luc; Ojcius, DAvid M.; Andrews, Charles W. Jr.; Korsmeyer; Stanley J.; Rank, Roger G.; Darville, Toni. "Role of Proapoptotic BAX in Propagation of Chlamydia muridarum (the mouse pneomonitis strain of Chlamydia trachomatis) and the Host Inflammatory Response". http://www.jbc.org/cgi/content/abstract/278/11/9496
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=427409 Edited by Marina Christou student of Rachel Larsen and Kit Pogliano