A Microbial Biorealm page on the genus Haemophilus somnus
Higher order taxa
Haemophilus somnus is a bacteria under the phylum proteobacteria. It is of the class, Gammaproteobacteria, in the order Pasteurellales, which typically live on the mucosal surface of birds and mammals, most notably in the upper respiratory tract. They are also of the family Pasteurellaceae. genus Histophilus
Use NCBI link to find]
species somnus Lineage Bacteria; Proteobacteria; Gammaproteobacteria; Pasteurellales; Pasteurellaceae; Histophilus
Description and significance
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.
Their genome (seq: RS: NC_008309) consists of a circular chromosome containing 2007700 base pairs and a plasmid(pHS129) is approximately 5178 bp in length. It is made up of roughly 34% GC content and 66% AT and contains genes coding for approximately 1798 different proteins and 65 RNA genes.
Cell structure and metabolism
Haemophilus somnus is a rod-shaped, gram negative bacteria. It is a facultative pathogen that has LOS is its major outer membrane component. It also contains bacterial transferrin receptors, which is a structure that contributes to its virulence (typically in cattle). Haemophilus has no flagella and is catalase negative.
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Typically live as a commensal organism in its host.
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Haemophilus somnus causes a wide variety of systemiatic diseases ranging from penumonia , abortion, arthritis, myocarditis, and septimia. It spreads throughout cattle herds in an elusive matter and become a major issue before it is even detected. There are 3 primary forms that h. somnus is able to assume: reproductive tract,urinary tract, respiratory tract form.
1.Reproductive and urinary tract form
In this form, h. somnus attacks the reproductive tract of pregnant cows, which may lead to the death of a fetus and subsequent abortion. This also causes the infection of the uterus and has been found in the urinary tract and prepuce of bulls which contracted the organism during mating. The excretion of uterine or vaginal discharge and urine of the infected animal also acts to transmit the disease to other unaffected cattle in close proximity, which become exposed to the organism by sniffing or by physically being contacted with the discharge. This can then lead to the respiratory form
2. Respiratory form
The respiratory form of this infection is able to attack both the upper and lower portions of the respiratory tract. Typically in calves, the upper respiratory tract is infected causing what is known as calf diptheria. The surface tussues of the larynx, also known as the voice box, become infected due to the interuption in blood supply, causing the tissue to die and become degraded, making it extremely difficult to breath. If the disease continues, the windpipe may also become infected as will be the lungs. If the infection occurs in the lungs, pneumonia may be the result, which can cause rapid death. However, although this is typically the primary cause of pnemonia, it is often outgrown by other organisms such as Pasteurella multocida and Pasteurella haemolytica.
3. The septic form
This form is developed from cirulation of infected blood awith cloincal signs depending on where the organism colonizes and blocks flow from forming a blood clot. The severity also depends on the amount of tissue death as a result of the blood clot. One case is if the blockage occurs in the brain or spinal cord, the disease can become nervous disorders.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Enter summaries of the most recent research here--at least three required
[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.
http://www.genome.jp/kegg-bin/show_organism?org=hso ; Haemophilus Somnus; KEGG
http://edis.ifas.ufl.edu/VM066; Richey, E. J. "Haemophilus somnus Disease in Cattle" University of Florida, IFAS Extension; Veterinary Medicine-Large Animal Clinical Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date December 1, 1990. Revised June 8, 2002.
http://scholar.lib.vt.edu/theses/available/etd-101398-081516/unrestricted/etd.pdf; Howard, Michael D.[et al]; Antigenic Characterization of Haemophilus somnus Lipooligosaccharide"; Virginia Polytechnic Institute, Veterinary Medical Science 1998
Edited by Christina Tam student of Rachel Larsen and Kit Pogliano