The bacterium V.cholerae is a gram negative, nonsporulating, straight or curved rod. It possesses a single polar sheathed flagellum and is highly motile.
A halophiclic organism, it is found in estuarine or marine environments, and it is growth in laboratory media is generally stimulated by the presence of 5 to 90 mM sodium, depending on actual culture conditions.
Outside the human host, Vibrio Cholerae has been found free living in water and also in association with plankton, most notably copepods.
In its most severe form, cholera is capable of causing death within 3 hr after the onset of symptoms, which occurs 12 to 72 hrs after ingestion of V. Cholerae.
The distinctive feature of the disease is the profuse secretory diarrhea that results from the action of cholera toxin on cells of the intestinal epithelium.
Fluid loss by this route can reach as much as 200 ml/kg of body weight per day with total losses exceeding 100% of body weight over the course of several days.
The concomitant loss of plasma solutes such as sodium potassium and chloride ions leads to electrolyte imbalances, acidosis and ultimately death.
However, effective treatment of cholera is both simple and relatively inexpensive, consisting of oral and/or intravenous rehydration therapy couples with administration of antibiotics.
Cholera typically begins with the ingestion of V. Cholerae in contaminated food or water.
Cholera is a non invasive infection where the organism colonizes the intestinal lumen and produces a potent enterotoxin.
In severe cases, the hypersecretion of sodium, potassium, chloride and bicarbonate induced by the enterotoxin results in a profuse, pale, watery, diarrhea containing flakes of mucus, described as rice water stools.
Unless the massive losses of fluid ad electrolyte are replaced, there is a fall in blood volume and pressure, an increase in blood viscosity. Renal failure, and circulatory collapse.
In fatal cases death occurs within a few days.
Vibrio Cholerae and Cholera
