Cholera

Cholera

: facultatively anaerobic gram-negative rods

Vibrio Cholerae�� , severe form of diarrhea�� vomiting�� ߱�, attached to small intestinal mucosa, produce a potent enterotoxin choleragen, �� choleragen�� Ż�� Ű�� ȴ�.

facally contaminated water�� Ϲ�� ݷ�� ̴�.

Vibrio Cholerae��

: curved, gram-negative, rod-shaped bacterium with a flagellum of one end

facultatively anaerobic

oxidase positive

tolerate strong alkaline conditions and high salt concentrations

choleragen

: cholera symptom�� ̴�.

heat labile

�� protein�� A, B �ΰ��part�� .

B�� toxicity�� µ�, intestinal cell�� microvilli�� specific receptor�� irreversible�ϰ� ��

A fragment�� toxicity�� ִ�.

causes the activation of the enzyme adenylated cyclase

this adenyl cyclase�� ATP�� cAMP�� ٲٴµ�, �̷�� ؼ� ��̴� cAMP�� , ��а� electrolytes�� secretion�� ϰ� �ǰ�, �̷�� ؼ� ��ڱ� �� 忡�� ó �� diarrhea�� ߱�Ǵ� ��̴�.

summary

Cholera

cause

Vibrio cholerae, a curved, gram-negative, rod-shaped, motile bacterium.

incubation period

Short, generally 12-48 hours.

symptoms

Abrupt onset of massive, painless diarrhea, generally followed by vomiting without nausea, muscle cramps, and when severe, dehydration and shock. Spontaneous recovery if fluid replacement is adequate.

epidemiology

Ingestion of fecally contaimnated food or water. Some natural sources, associated with marine crustaceans. Asymptomatic carriers occur.

laboratory diagnosis

Recovery of V. cholrae from cultures of feces of vomitus on special media.

pathogenesis

Heat-labile enterotoxin causes excessive secretion of water and electrolytes by the intestinal epithelium.

treatment

A solution of electrolytes and glucose, given intravenously in severe cases; or similar electrolyte solution containing a glucose source given by mouth in milder cases; orally administered tetracycline antibiotic.

prevention

Purification of water and careful hand washing. Vaccination gives short-lived, partial protection.

cause	Vibrio cholerae, a curved, gram-negative, rod-shaped, motile bacterium.
incubation period	Short, generally 12-48 hours.
symptoms	Abrupt onset of massive, painless diarrhea, generally followed by vomiting without nausea, muscle cramps, and when severe, dehydration and shock. Spontaneous recovery if fluid replacement is adequate.
epidemiology	Ingestion of fecally contaimnated food or water. Some natural sources, associated with marine crustaceans. Asymptomatic carriers occur.
laboratory diagnosis	Recovery of V. cholrae from cultures of feces of vomitus on special media.
pathogenesis	Heat-labile enterotoxin causes excessive secretion of water and electrolytes by the intestinal epithelium.
treatment	A solution of electrolytes and glucose, given intravenously in severe cases; or similar electrolyte solution containing a glucose source given by mouth in milder cases; orally administered tetracycline antibiotic.
prevention	Purification of water and careful hand washing. Vaccination gives short-lived, partial protection.