Vibrio cholera Vibrio parahaemolyticus
DR .Ruaa Elias College of Medicine Department: Microbiology*
List of Contents:
Objectives Introduction Important properties Transmission-worldwide Biological classification Diagnosis Antigenic structure Virulence factors Clinical Finding Diagnosis Treatment*
Objectives:
- Vibrio cholera infection is horizontal transmission may occur via fecal oral route specially from drinking contaminated water -Vibrio cholera remains in lumen of small intestines and cause Severe diarrhea(cholera ) -Epidemic can occur anywhere -The students must learn all detail about the virulence factors,pathogenicity and diagnosis, treatment of these very important bacteria*
Introduction
-Vibrio cholera is a genus of Gram-negative bacilli bacteria in the Enterobacteriaceae family. -They are among the most common bacteria in surface water worldwide.*
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Vibrio cholera Vibrio parahaemolyticus Important properties: 1- They are curved Gram negative rods, motile, non-capsulated, non- spore forming bacteria. 2- Most important strains is Vibrio cholera O1, O139
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-Human GI Tract is the reservoir for the organism - Vibrio cholera may exist free living in fresh water
- Horizontal transmission may occur via fecal oral route specially from drinking contaminated water -Epidemic can occur anywhere
Transmission-worldwide
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Biological classification Vibrio cholera has two biotypes 1- Classical 2- El-Tor The two biotypes are distinguished on the basis of hemolysis and antimicrobial susceptibility.
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- Vibrio cholera has somatic lipopolysaccharides (O-Antigens) that confer serologic specificity There are more than 140 (O) antigen groups. The group O1 antigen has 3 determinants which occur in combinations and are termed 1- INABA 2- OGAWA 3- HikOJIMA
Antigenic structure
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1- Exotoxin (Enterotoxin) (Cholera toxin). Consists of subunits A and B. 2- Ganglioside GM1 serve as the mucosal receptor for subunit B which promotes entry of subunit A into the cell.
Virulence factors
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Virulence factors
Subunit A activates adenylate cyclase and results in prolonged hyper secretion of water and electrolytes as much as 20L daily leading to sever dehydration, Acidosis, shock and death.IQ016-109500-0720*
CholeraSymptoms; painless, voluminous and odorless “rice water”diarrhea. No fever. Can be fatal-Vibrio cholera remains in lumen of small intestines. Severe diarrhea, Vomiting, Muscle cramps (leg cramps), Dehydration, Electrolyte imbalance. Clinical inding
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Clinical Finding
-Hypotension, Loss of skin turgor, Sunken eyes, Renal failure, Death. -Complications: electrolyte losses and imbalances, metabolic acidosis, hypoglycemia (especially in children) and abortion in pregnancy*
Clinical Finding -Diagnosis is based on symptoms, history, and stool culture “rice water”diarrhea. curved Gram negative rods. *
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Watery Diarrhea in Cholera (Rice Water)
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Vibrio cholerae
Vibrio parahaemolyticus*
Vibrio parahaemolyticus Beta hemolytic on blood-agar
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Summary
Vibrio cholera is curved Gram negative bacteria in the Enterobacteriaceae family.-They are among the most common bacteria in surface water worldwide.iinfection is horizontal transmission may occur via fecal oral route specially from drinking contaminated water, epidemic can occur anywher Vibrio cholera remains in lumen of small intestines and cause Severe diarrhea(cholera). Has two biotypes: Classical , El-Tor and has more than 140 (O) antigen groups .They produce virulance facter :Exotoxin (Enterotoxin) (Cholera toxin) Consists of subunits A and B. The Symptoms; painless, voluminous and odorless “rice water”diarrhea. No fever Can be fatal .Treatment Immediate and continuous oral or IV replacement of fluids and electrolytes is absolutely essential andTetracycline or Doxycycline to speed up recovery. *
References
Medical Microbiology, edited by Jawetz,E., Brooks,G.F.; Carroll,K.C.;Butet,J.S.; Mores,S.A.and Mietzner,T.A. 2010. 25 th ed. Medical Microbiology, edited by Jawetz,E., Brooks,G.F.; Butet,J.S and Mores,S.A. 2004. 23 th ed. Internet access.
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