Exam 3 Lecture 23 Flashcards
True or False: Most Vibrio species do not cause human infection.
True
Describe the Gram Stain of Vibrio
Gram-negative rods (comma, curved, or straight)
Vibrio species are ____ and have a _____ polar flagellum.
motile, single
Vibrio is a ______, meaning that it can grow in ____ environments. It is typically found in _____ water.
halophile, salty, brackish
Vibrio likes to grow in ____ temperatures and also likes high ______.
warm, salinity
Vibrio species often feed on ____ found in shellfish.
chitin
True or False: cases of Vibrio decrease during the summer.
False
How many species of Vibrio are capable of causing human disease?
~20
Vibrio cholerae causes ______, while illnesses caused by other diseases is called ______.
cholera, vibriosis
How is cholera transmitted?
ingestion of contaminated food or water
If cholera is left untreated, a patient can die from ________ in less than __ hours.
dehydrated, 24
We are currently in the ___ cholera pandemic.
7th
Who found out that V. cholerae is present in the intestinal contents of victims who died of cholera?
Filippo Pacini
Who isolated V. cholerae in culture?
Koch
True or False: Humans are the only known vertebrate hosts of V. cholerae, and it depends heavily on humans for growth
False - not dependent on humans (can grow in water)
Stools shed from cholera patients have ____ V. cholerae cells/mL
10^9
Which V. cholerae serogroups are known to cause widespread epidemics?
Serotypes O1 and O139
Serotypes O1 and O139 produce _____ _____.
cholera toxin
Where does V. cholerae colonize and multiply?
Small intestine
What are the 2 main virulence factors present in V. cholerae?
1) Cholera toxin
2) Toxin coregulated pili (TCP)
What is the function of TCP?
allows V. cholerae to colonize the small intestine
Describe the mechanism of action of Cholera toxin
It enters host epithelial cells and increases levels of cAMP, and this causes host cells to release ions (Na+, K+, Cl-, HCO3-) and water is released to compensate
Symptoms of cholera commonly appear about __ to __ days after infection.
2 to 3
What percentage of people develop severe cholera?
5-25%
In the initial stages, diarrhea contains intestinal contents, but the diarrhea becomes ____ and this becomes known as ____ ____ ____
water, rice water stool
What’s the infectious dose for cholera?
10^8
True or False: Depending on your blood group, you may experience different disease severity.
True
Which blood group is associated with more severe cholera?
O group
Preexisting V. cholerae immunity is helpful in that patients can be _________ colonized or develop ____ illness
asymptomatically, mild
Name a host factor that may lead to severe cholera
less acidic stomach
What is the primary focus of cholera treatment?
fluid replacement
How many liters of fluid can be lost per day from severe dehydration?
20 liters
True or False: Without treatment, cholera has a fatality rate of 50%, but with fluid replacement, mortality falls under 1%
True
Name an example of inadequate cholera treatment
not matching ongoing fluid loss w/ fluid replacement
What may be causing delayed treatment for cholera?
limited cholera treatment centers
What is used to monitor the amount of fluid loss from cholera?
cholera cot
What is included in rehydration fluids?
sodium, potassium, chloride, bicarb, glucose
Severe dehydration is often treated with __ _____
IV fluids
________ play a secondary role in cholera treatment
antibiotics
Antibiotics may play an important role in ……….
decreasing cholera transmission
True or False: Many cases of Vibrio cholerae are found in the US yearly
false - only 7 were reported in 2014
Where are cholera cases commonly seen?
developing nations that lack access to drinking water + proper sanitation (or after a humanitarian crisis that collapses infrastructure)
Cholera is endemic in many areas of …………………
Africa, Latin America, South Asia
