Lecture 12- Vibrio Species

Question 1

Vibrio sp.

Answer 1

• nonspore-forming, gram-negative

- vibrio shaped bacterium

Question 2

What are the 3 species of vibrio that are known to cause most infections?

Answer 2

Vibrio parahaemolyticus
Vibrio vulnificus
Vibrio cholera

Question 3

The vibrio infection are most associated with what?

Answer 3

Seafood consumption

-vibrio in water are part of the natural microbiota of the water

Question 4

Is vibrio caused by fecal contamination?

Answer 4

No, the fecal oral route does not apply to Vibrio

Question 5

What is the serotypes of v.parahaemolyticus?

Answer 5

LPS (O) antigen, and capsular polysaccharide (K) antigen

Question 6

What is the generation time and temperature for V.parahaemolyticus?

Answer 6

Generation time: 8-9min at 37C

-the ability to grow rapidly means that contaminated food becomes highly colonized if temperature abused

Question 7

Symptoms of Vibrio parahaemolyticus

Answer 7

appear 4-30 hours after ingestion of contaminated food

• D, N, V, abd cramps, fever
• subside in 3-5 days

Question 8

How many flagellum does v. parahaemolyticus have and where is it located?

Answer 8

single flagellum at one pole of the bacterium is required for swimming motility
-during growth in semi-solid media, flagella are produced along the lateral side of the bacterium

Question 9

What is the role of MAM7 in v. parahaemolyticus?

Answer 9

Multivalent adhesion PRO that binds to fibronectin and phosphatidic acid which is required for the initial attachment to host cells

Question 10

What are the haemolysis factors that v. parahaemolyticus have?

Answer 10

-Fe transporters are internalized by diff membrane receptors on the outer membrane of the bacteria and transported to the cytoplasm by different ABC complexes.

Question 11

What are the 3 toxins produced by v. parahaemolyticus?

Answer 11

1. thermoliable haemolysin (tlh)
2. thermostable direct haemolysin (tdh)
3. thermostable direct-realted haemolysin (trh)

Question 12

How are thermostable direct haemolysin (TDH) and thermoliable haemolysin (TLH) secreted?

Answer 12

secreted from the bacteria and form tetrameric pore complexes in the host membrane
the pores allow ions to flow freely across the host membrane which leads to hemolysis or cytotoxicity

Question 13

What functions do T3SS1 effectors have?

Answer 13

VopQ, VopR, VopS, and VPA0450 are effectors that are translocated into the host cells to cause cytoxicity in different cell types such as macrophages and HeLa cells

Question 14

Where is T3SS1 found?

Answer 14

in all V.parahaemolyticus isolates, even non-pathogenic isolates, indicating an imp. role in the environment

Question 15

What function do T3SS2 effectors have?

Answer 15

Vop A, VopC, VopL, VopT are translocated into host cells to cause cytotoxicity of colon epithelial cells or enterotoxicity within the host

Question 16

Where is T3SS2 found?

Answer 16

mainly in clinical isolates indicating that it is more tightly ties to a pathogenic lifestyle

Question 17

What are the 4 effector of T3SS1?

Answer 17

VopQ, VopR, VopS, and VPA0450

Question 18

What are the 4 effectors of T3SS2?

Answer 18

VopA, VopC, VopL, and VopT

Question 19

Which species has the most serious infection and is responsible for 95% of seafood related deaths in North America?

Answer 19

V. vulnificus

Question 20

What are the 3 biotypes of v. vulnificus?

Answer 20

1. Causes diseases in humans
2. causes disease in eels, rarely in humans
3. hybrid of type 1 and 2, found only in Israel

Question 21

What is the primary syndrome of v. vulnificus?

Answer 21

Primary septicemia caused by consumption raw or undercooked seafood

Question 22

What is the second syndrome of v. vulnificus?

Answer 22

necrotizing wound infection which results from an open wound being exposed to warm seawater, or contaminated seafood, with high concentration of v. vulnificus

Question 23

Fatality rate of primary septicemia from v. vulnificus?

Answer 23

60% –> high usually from the consumption of oysters

Question 24

Symptoms of v. vulnificus?

Answer 24

appear 7 hours to several days after exposure

-fever, chills, N, hypotension

Question 25

virulence factor v. vulnificus k antigen

Answer 25

polysaccharide capsule - if cells loose the K-antigen they lose virulence - the role in virulence is not understood

Question 26

virulence factor v.vulnificus LPS (O antigen)

Answer 26

the high fever, systemic infection, and shock are consistent with LPS induced endotoxic shock

Question 27

virulence factor v.vulnificus vvhA?

Answer 27

a heat stable haemolysin/cytotoxin that is unique to V. vulnificus and likely plays a role in virulence

Question 28

Where was the cholera outbreak in 2010?

Answer 28

Haiti where the mortality rate was the highest | Yemen where the people with cholera is high but death is lower than in Haiti

Question 29

What is the serotyping of v.cholerae based on?

Answer 29

LPS (O) antigen

Question 30

what are the two type of v. cholerae that cause epidemic and pandemics?

Answer 30

O1 and O139

Question 31

What toxin do the two v. cholerae strain produce?

Answer 31

Cholera toxin (CTX)

Question 32

What does the cholerae toxin do (CTX)?

Answer 32

disrupts the ion transport, this leads to severe diarrhea - carried on a phage , only v. cholerae which are infected with this phage are able to cause illness in humans - binds to ganglioside receptors on the surface of intestinal epithelium cells - internalized by endocytosis and triggers the production of cAMP

Question 33

does v. cholerae have a VBNC state?

Answer 33

Yes, where cells are reduced in size and become ovoid

Question 34

What factors does v. cholerae use to colonize the small intestine?

Answer 34

adherence factors

Question 35

cAMP is triggered by cholera toxin but what does it do after that?

Answer 35

activates specific ion channels within the cell membrane causing an efflux on ions from the cell - the build up of ions in the intestinal lumen draws water from cells and tissues via osmosis causing acute diarrhea and dehydration

Question 36

which species is known to undergo rapid horizontal gene transfer and why?

Answer 36

V. parahaemolytics because the two genes (K and O antigen) are in two discrete clusters which undergo horizontal gene transger

Question 37

What needs to happen for v. cholerae to be infected?

Answer 37

needs to be infected with a phage to be virulent | - climate change increases the probability

Question 38

can T3SS be transferred from v. parahaemolyticus to v. cholerae?

Answer 38

yes, when this happens it makes v. cholerae pathogenic to humans

Question 39

What are some prevention of vibrio infections?

Answer 39

- seafood should always be frozen, refrigerated, or stored in ice, eaten fresh - cooking very effective at eliminating vibrios - irradiation and high hydrostatic pressure - dried spices, herbal oils, tomato sauce, lemon juice

Question 40

Does depuration (filter feeding bivalves are purified by pumping through clean water) remove Vibrio?

Answer 40

no but does remove salmonella and e.coli

Question 41

which species of vibrios has the highest mortality rate?

Answer 41

V. vulnificus