Eubacteria-Salmonella+enterica

=// Salmonella enterica //= = =

** Scientific Classification **

 * **Scientific Name** || //Salmonella enterica// ||
 * **Kingdom** || Eubacteria ||
 * **Phylum** || Proteobacteria ||
 * **Class** || Gammaproteobacteria ||
 * **Order** || Enterobacteriales ||
 * **Family** || Enterobacteriaceae ||

Introduction
Salmonella was discovered in 1884 by American scientist, Dr. Daniel Salmon. //Salmonella enterica are rod shaped (//baccillus) bacteria. They are commonly found in raw meat, chicken, contaminated water, and even egg shells. Upon entering the host such as an animal, it stays in its intestinal tract. Three variasions of //Salmonella enterica// are Typhi, Enteritidis, and Typhimurium. They DNA are almost identical. Each kind is responsible for a different kind of diease. For example, //Typhi//, which is found in contaminated water, is responsible for typhoid fever (hence the name "typhi"). This disease usually occurs in poor, underdeveloped countries. in contaminated water. A human can become infected by drinking the contaminated water or even by washing other foods with the water. T//yphimurium// used to be the most common cause of food poisoning. However, nowadays, enteritidis is the most common cause of food poisoning. Since it spreads through chickens, it will enter the human body once the chicken has been consumed.

Cell structure and Metabolism
Salmonella enterica are motile, rod shaped bacteria (baccillus). They have uniformly distributed flagella. Once inside their hosts, they produce specific proteins that disrupts the cells of the intestinal walls. This disorganizes the intestinal cells.

//Salmonella enterica// use hydrogen as an energy source. Researchers have discovered that this bacteria contains three membrane related enzymes that help break down the hydrogen. This capability makes this particular bacteria to be unique.

Other cellular characteristics:
 * //Salmonella typhi// has a large circular chromosome which consist of two plasmids (pHCM1 and pHCM2)
 * //S//. //typhimurium// has a circular chromosome with only one plastid (pSLT)

**Fascinating Fact:** While the genus Salmonella consists of two species (S. enterica and S. bongori) it comprises of over 2,000 serovars

Phylum Proteobacteria
This phylum is a very large group of bacteria. It contains about 1534 species. All organisms of the proteobacteria phylum are composed of lipopolysaccharides. Although many of them move using flagella, some are non-motile. This phylum consist of a diverse range of organisms such as nitrifying bacteria, enteric bacteria, as well as bacteria associated with animal bioluminescence.



Habitat
//Salmonella// can be found in poultry, red meat, and raw egg shells. It also exists among reptiles and amphibians. Interestingly, this bacterium can also be found in most home kitchens. Fortunately, one can be protected with proper food handling and cooking. Another place where //Salmonella// can be found worldwide is in contaminated water.

**Fascinating Fact:** The Salmonella genus contains over 2500 serotypes,all of which are pathogenic to humans.

** Pathology **
Salmonella enterica is capable of causing diseases such as gastroenteritis and typhoid fever. This bacteria can be transmitted through the ingestion of contaminated food and water. Salmonella infections usually cause fever, abdominal pain, and diarrhea. Typically, victims infected with Salmonellosis(infection with Salmonella bacteria) can get better without treatment after a week. However, this is not the case if the host is severely dehydrated or if the infection spread. Then, it would require the use of certain antibiotics. Most people who had Salmonellosis have recovered completely. Nevertheless, there are cases where these people develop Reiter's syndrome(pain in joints) and other syndromes which can last for months or years.



How S. typhimurium invades an epithelial cell of the intestinal tract:

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** Resources: **
Bacteria. ( 2010). In //Encyclopædia Britannica.// Retrieved November 15, 2010, from Encyclopædia Britannica Online School Edition: []

Ingleton, Paul, & Diana Sainsbury. (1981). //Introduction to bacteria: for students in the biological sciences//. Chichester: John Wiley & Sons.

Dyer, Betsey Dexter. (2003). //A field guide to bacteria.// N.Y.: Cornell University Press.

Heritage, J., E. G. V. Evans, & R. A. Killington. (1999). //Microbiology in action//. Cambridge, UK: Cambridge University Press.

Betsy, Tom, & Keogh, Jim. (2005). //Microbiology demystified.// New York: McGraw-Hill.

Postgate, J. R.. (2000). //Microbes and man//. 4th ed. New York: Cambridge University Press.

Image Resources:
//Salmonella typhi//. [Photograph]. Retrieved November 15, 2010, from Encyclopædia Britannica Online School Edition: []

//Dennis Kunkel Microscopy, Inc//. (2008). //Science Stock Photography.// Retrieved from []

//Kenneth Todar//. (2009). //Structure and Function of Bacterial Cells.// Retrieved from []

//Kenyon College.// (2010). //Samonella//. Retrieved from []