12-vibrio species Flashcards
Vibrio is a ____, ____, ____ bacterium
non spore forming, gram neg and vibrio shaped
most illness is caused by which 3 vibrio species
vibrio parahaemolyticus, vibrio vulnificus and vibrio cholera
which species is more waterborne than foodborne?
vibrio cholera
vibrio is a predominant bacterial genus in___
estuarine waters
vibrio infection is generally associated with _____ consumption
seafood (or contact with seafood)
why are there spikes in vibrio infections in the summer?
because vibrio numbers vary by water temp ie. in Canada when the water that oysters are harvested from goes above 17 deg C its
Vibrio parahaemolyticus is serotyped based on its
LPS (O), and capsular K antigen
Infection of parahaemolyticus is linked to consumption of
raw and undercooked seafood
symptoms of v para infection
-4-30 hours after ingestion; diarrhea, ab cramps, nausea, vommitting and fever. symptoms subside after 3-5 days
how does vibrio parahaemolyticus work to cause infection
- single flagellum at one pole of the bacterium is required for swimming motility
- grow on lateral side of bacterium which aid in the swarming motility
- MAM7 adhesion protein that binds to fibronectin and phosphatidic acid which is required for the initial attachment to host cells.
- scavenges iron and then causes haemolysis
- iron transporters are internalised by diff membrane receptors on the outer membrane of the bacteria and transported to the cytoplasm by diff ABC complexes.
vibrio parahaemolyticys produces what 3, haemolytic toxins
- thermoliable haemolysisn (tlh)
- thermostable direct haemolysin (tdh)
- thermostable direct-related haemolysin (trh)
The TDH and TRH toxins are secreted from the bacteria and form _____ in the host membrane
form tetrametric pore complexes
what is the purpose of the tetrametric pore complexes
allow ions to flow freely across the host membrane which leads to hemolysis or cytotoxicity
are translocated into host cells to cause cytoxicity of colon epithelial cells or enterotoxicity within the host
T3SS2 effectors
found in all V parahaemolyticus isolates even non pathogenic isolates and translocates into host cells to cause cytoxicity in different cell types such as macrophages and HeLa cells.
T3ss1 effectors
T3ss2 is found mainly in _____ and this indicates what
- clinical isolates
2. tightly tied to a pathogenic lifestyle
a petachial rash is a symptom of
vibrio vulnificus
T or F: v vulnificus is not serotyped
T
what are the 2 distinct v vulnificus syndromes
- The first is a primary septicaemia caused by consuming raw or undercooked seafood
- The second is a necrotizing wound infection which results from an open wound being exposed to warm seawater, or contaminated seafood, with high concentrations of V. vulnificus
you eat raw oysters and you also had a pretty gnarly cut on your hand when you were preparing your food. 7 hours to several days after exposure, you have symptoms that include fever, chill, nausea and hypotension.
vibrio vulnificus
virulence factors of v vulnificus include
k antigen, LPS and vvha (heat stable haemolysin and cytotoxin)
related to poor water sanitation systems and malnutrition
vibrio cholerae
serotyping of v cholerae is based on
LPS (O) antigen
T or F: V cholerae has a viable but not culturable state
True
how does infection from cholerae lead to diarrhea
-v cholerae colonizes the small intestine using adherence factors.; it produces the CTX toxins which binds to surface ganglioside receptors.
-CT is internalized by endocytosis and triggers the production of cyclic AMP within the cell.
-cyclic AMP activates specific ion channels within the cell membrane causing an efflux of ions from the cell.
-the build up of ions in the intestinal lumen draws water from cells and tissues via osmosis = diarrhea
which disrupts ion transport, this leads to severe diarrhea
ctx is carried on a ____,
pahge therefore only v cholerae which are infected with this phage are able to cause illness in humans.
T or F; v parahaemolyticus is known to switch its serotypes mid outbreak
True, V. parahaemolyticus carries the genes for its K and O antigens in two discrete clusters, which can rapidly undergo horizontal gene transfer
how can vibrio infection be prevented
- vibrios are sensitive to cold
- heating
- irradiation and hydrostatic pressure
- herbs and species
virulence factor is the CTX toxins
cholerae
parahaemolyticus has what virulence factors
tdh and trh
v vulnificus has what virulence factors
capsule, LPS and vvha
