Helicobacter pullorum: Difference between revisions
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[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1728516/pdf/v049p00601.pdf O’Rourke, J.L, Grehan, M., and Lee, A. “Non-pylori helicobacter species in humans”. Gut Journal. 2001. Volume 49. p. 601-606.] | [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1728516/pdf/v049p00601.pdf O’Rourke, J.L, Grehan, M., and Lee, A. “Non-pylori helicobacter species in humans”. Gut Journal. 2001. Volume 49. p. 601-606.] | ||
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3020539/ Manfreda, G., Parisi, A., Lucchi, A., Zanoni, R.G., and De Cesare, A. “ Prevalence of Helicobacter pullorum in Conventional, Organic, and Free-Range Broilers and Typing of Isolates”. Applied and Environmental Microbiology. 2011. Volume 77. p. 479–484.] | |||
[http://http://www.ncbi.nlm.nih.gov/books/NBK2448/ Schauer, D. "Enterohepatic Helicobacter Species." Helicobacter Pylori: Physiology and Genetics. Washington D.C.: ASM, 2001.] | [http://http://www.ncbi.nlm.nih.gov/books/NBK2448/ Schauer, D. "Enterohepatic Helicobacter Species." Helicobacter Pylori: Physiology and Genetics. Washington D.C.: ASM, 2001.] | ||
Revision as of 20:28, 18 October 2011
NEUF2011
Classification
Higher order taxa
Domain Bacteria; Phylum Proteobacteria; Class Epsilonproteobacteria; Order Campylobacterales; Family Helicobacteraceae
Species
Genus Helicobacter; Species pullorum;
Helicobacter pullorum; H. pullorum
Description and significance
Helicobacter pullorum is a gram-negative bacteria in the genus Helicobacter. The cells are bacilli with a slight curve. They typically are 3-4 micrometers in length, and 0.3-0.5 micrometers in width. This bacteria species was discovered from chickens, specifically broiler and laying types, and has also been found in humans diagnosed with gastrointestinal disease. They live in the intestinal tract of their host species but can also infiltrate the liver, ultimately causing hepatitis. H. pullorum thrive in an environment of 37-42 degrees Celsius and are therefore classified as mesophiles, in the higher end of that temperature range. They grow in microaerobic conditions and are non-spore forming. H. pullorum can also be classified by its response to certain tests. The species is negative for indoxyl acetate esterase, urease and alkaline phophatase production. It tests positive, however, for catalase production.
H. pullorum is an avian helicobacter, and is known to infect both birds and mammals. The species is of significance as it is associated with enteritis and vibrionic hepatitis in poultry. It is also associated with gastroenteritis, diarrhea, liver, and gall bladder disease in humans, and it is speculated that it may play a role in Crohn’s disease.
The amount of infections caused by H. pullorum is most likely underestimated due to its similarities between the genera Helicobacter and Campylobacter. There is a potential for food-borne transmission of H. pullorum to humans, as it has been recognized that Campylobacter species is capable of this. A number of cases concerning the species as a major-food associated human pathogen have been reported, however, there is lack of evidence supporting the prevalence of H. pullorum in humans.
Genome structure
Helicobacter pullorum has a circular genome consisting of 1,919,070 nucleotides with a known sequence. The DNA codes for 2044 genes, 2008 of which are protein coding and 36 of which are structural RNAs. 33% of the genome consists of GC pairings.
Cell structure and metabolism
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Being Gram negative, Helicobacter pullorum has two cell membranes. The cell is unable to grow at 25 degrees Celsius, but grows at 37 degrees Celsius under microaerobic conditions. Under aerobic conditions at 37 degrees Celsius, H. pullorum will not grow. Most Heliobacter cells have bundles of multiple sheathed flagella. However, H. pullorum has one single flagellum that is nonsheathed. H. pullorum produces catalase, reduces nitrates, and does not produce urease or alkaline phosphatase. It also produces cytolethal distending toxin, which causes distension in certain cell lines, causing the cell to disintegrate and die.
Ecology
Habitat; symbiosis; contributions to the environment.
Mucous is the natural niche of the genus helicobacter. The prevalence of colonized spiral shaped bacteria in the gastric mucosa of most animals demonstrates this. It is likely that the spiral shape of the bacteria give it a selective advantage in this viscous environment. H. pullorum is a member of the enterohepatic helicobacters, which colonizes mainly in the intestine and the hepatobiliary system. The species is naturally found in chickens and birds, and was originally isolated from chickens. There is a possibility that humans may have helicobacter as a part of their normal flora in their lower bowel. However, there is lack of evidence to support this idea. H. Pullorum has also been isolated in fecal samples from humans with gastroenteritis, as well as from the gallbladders of women who had chronic cholecystitis, and from the livers of patients suffering from cirrhosis or hepatocellular carcinoma.
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Current Research
Enter summarries of the most rescent research here--at least three required
References
