Download Vibrio cholerae

Vibrio cholerae
Microbiology Pathogen Project
Charlene Ashley & Liz Sarkisian
Tests to identify
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Stool sample taken for culture
Gram stain negative
Catalase positive
Oxidase positive
Indole test positive
Non-fermenter on MacConkey agar
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.
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
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.
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 .
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 .
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.
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.
• 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.