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Cholera. Vibrio cholerae (bacteria). Cholera Bacterium. Special Features. Cholerae has two plasmids, and two chromosomes. One of these codes for the Cholera toxin. Cholera Toxin is the toxin that causes the host’s body to excrete water, Na+, K+, Cl-, and HCO3+.
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Cholera Vibrio cholerae (bacteria)
Special Features • Cholerae has two plasmids, and two chromosomes. • One of these codes for the Cholera toxin. Cholera Toxin is the toxin that causes the host’s body to excrete water, Na+, K+, Cl-, and HCO3+. • It also codes for toxin coregulated pili. These pili help the bacteria bind to the host’s cells. • Cholera has two proteins, named hemagglutinin and acf (accessory colonization factor). These help with the adhesion between the host and the bacteria. • Cholera also produces a protease called mucinase that destroys proteins. It’s purpose is unknown.
History • Cholera has been an issue across the world for ages in places such as India and Rwanda. • “El Tor,” is the name of the global cholera epidemic. It began in 1969 and arrived on the west coast of South America in 1991. This epidemic hit 1041422 people and killed 9642 by 1994. Almost 5 times more than the number of cases the previous year. • In 1997, an outbrake hit Rwanda, causing 90000 cases.
REPORTED CASES In the USA
COMMOM DISEASE(s) / SYMPTOMS • The symptoms of Cholera can occur in a range from a few hours up to five days later from when first infected. • “Watery diarrhea that appears to have flakes of white rice and a “fishy” odor, rapid heart rate, dry skin or mouth, excessive thirst, lack of tears, glassy eyes, unusual sleepiness, little urine, cramps in the abdomen, and nausea/ vomiting.” • These symptoms can range from mild to severe.
HOW DOES PATHOGEN ENTER THE BODY • Cholera can enter the body through contaminated drinking water or eating contaminated food. In an epidemic, the source of the Cholera is usually in the stool of the infected person. The disease can spread quickly with inadequate treatment of sewage and drinking water.
HOW DOES PATHOGEN ENTER THE BODY (2) • The cholera bacterium may also live in the environment in brackish rivers and coastal waters. Shellfish eaten raw have been a source of cholera, few in the U.S. have gotten it. The disease is not likely to spread from one person to another because it spreads due to poor environmental conditions.
REPLICATION/ SPECIAL FEATURES • The replication process of cholera is compared to the replication process of E. Coli, although little is known about replication of bacteria containing two chromosomes. • Cholera has several proteins that help with the replication process: DnaA, RctB, IHF, and Dam. These proteins bind to the chromosomes to initiate the replication process.
Replication: In further Depth • DnaA: promotes the unwinding of the chromosomes. • IHF (integration host factor): stimulates unwinding. • Dam (DNA adenine methyltransferase): the enzyme that is involved in the timing of replication.
TREATMENT • Cholera is easily treated. The oral rehydration of salts replaces a lot of the fluid and electrolytes lost through diarrhea and vomiting. • When traveling, a simple prevention tool is “’Boil it, cook it, peel it, or forget it!’"
Occurrence key: yellow = low, orange = medium, and red = high
TREATMENT (2) • Even though Cholera is easily treatable, if left untreated, it can lead to death. “Cholera continues to be perceived by many as a deadly and highly contagious threat that can spread through international trade in food.”
Special Thanks To: • http://www.who.int/topics/cholera • http://www.medicinenet.com/cholera/page2.htm • http://www.umm.edu/ency/article/000303sym.htm • http://letsgoeverywhere.files.wordpress.com/2007/11/cholera.jpg • www.textbookofbacteriology.net/cholera • Jb.asm.org/cgi/reprint/188/17/6419.pdf
Special Thanks To: • http://geo.arc.nasa.gov/sge/health/sensor/diseases/images/cholera97.gif • http://dsol-smed.phac-aspc.gc.ca/ dsol-smed/ndis/disease2/dis2figs/ cholera_e.gif • http://bepast.org/docs/photos/cholera/vibrio%20comma%20asiatic%20cholera.jpg • http://www.cbc.ca/gfx/images/news/photos/2008/05/09/cholera-cp-2031106.jpg