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 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.

Vibrio parahaemolyticus 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 O1, O139

Transmission-worldwide -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

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.

Antigenic structure - 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

Virulence factors 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 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

Clinical inding Cholera Symptoms; 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 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.

Watery Diarrhea in Cholera . Watery Diarrhea in Cholera (Rice Water)

Vibrio cholerae Vibrio parahaemolyticus

Vibrio parahaemolyticus Beta hemolytic on blood-agar

Treatment 1- Immediate and continuous oral or IV replacement of fluids and electrolytes is absolutely essential. 2- A solution of table salt plus cooked rice together in water can substitute as an oral home treatment. 3- Tetracycline or Doxycycline to speed up recovery.

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 .

Question?

Thanks a lot