Vibrio cholerae

1. Vibrio cholerae Microbiology Pathogen Project Charlene Ashley & Liz Sarkisian

2. Tests to identify • Stool sample taken for culture • Gram stain negative • Catalase positive • Oxidase positive • Indole test positive • Non-fermenter on MacConkey agar

3. Morphology • Curved bacillus with a monotrichous flagellum and pili for adhesion • Characteristics : Halophilic, facultative anaerobe • Secretes powerful enterotoxins, including cholera toxin that pumps fluids out of the body and into the intestines resulting in diarrhea. The toxins loosen tight junctions called zonula occludens increasing permeability and fluid secretion and allowing for the bacteria to move around easily.

4. Mechanism of transmission and prevention • Cholera is associated with poor sanitation. Hand washing and proper water and sewage treatment would help prevent cholera in developing nations. It is transmitted via (primarily fecal) contaminated food and water. In the U.S. , cholera is associated with contaminated shellfish. • Type of infections caused :Causes cholera, “The Mother of all Diarrhea” • High infectious dose, greater than 10, incubation 2-3 days

5. Symptoms of disease • Ranges from mild self limiting diarrhea and vomiting to acute voluminous diarrhea (characterized by rice water stools) resulting in severe dehydration, even death, within hours. Fifty percent of untreated patients with severe cholera die.

6. Treatment options • It is not the Vibrio cholera that is fatal- it is the rapid dehydration that is fatal, so treatment is to replenish fluids and electrolytes .

7. Epidemiology • Vibrio cholera is found in the small intestine and increases mucus production causing fatal diarrhea and vomiting which result in extreme dehydration . • Body sites: Located on the surface of cells that line the intestinal mucosa. • Reservoirs: Water serves as a reservoir as well as contaminated food .

8. History • Vibrio cholera is an ancient disease. Records from Hippocrates ( 460-377 BCE ) and the Indian Peninsula describes an illness of cholera. • The 19th century English physician John Snow provided the first demonstration that the transmission of cholera was significantly reduced when uncontaminated water was provided to the population.

9. History • In 1855, a wave of cholera ravaged citizens of London. Thousands became ill and died before John Snow identified the Broad Street water pump as the single source of outbreak. Today, all patrons of the John Snow pub can enjoy a pint of local ale, and even more importantly, a refreshing glass of crystal clear, pathogen- free water.

10. The discovery of cholera organism was credited to Robert Koch in 1883 during an outbreak in Egypt. Since 1817, seven cholera pandemics have occurred. The pandemics originated from cholera’s endemic reservoir in Indian subcontinent and five affected Europe and four reached the U.S. • Cholera spread rapidly throughout the world after the 1817 endemic, largely due to inadvertent transport of bilge water, mainly from British ships, acquired from Bay of Bengal that contained the organisms. It then rapidly moved throughout Europe and into Russia. The French were the ones who brought it into the New World, and in 1832, it spread south from Montreal and caused an epidemic in New York City . • Since 1961, there have been seven major cholera pandemics, affecting millions of people living in South America, Africa, Europe and Asia.