vibrio

vibrio is gram?

gram negative

is vibrio microaerophilic or facultatively anaerobic

anaerobic

vibrio type of rods

fermentative rods

vibrio is oxidase?

positive w/ polar flagella

vibrio has 3 particularly important pathogens

v. cholerae, v. parahemolyticus, v. vulnificus

grows in temperature range of?

14-40 c

all species req?

NaCI for growth

v. cholerae can grow without?

additional salt

vibrio can tolerate a wide range of pH. what is the range?

6.5-9.0

vibrio are susceptible to?

stomach acids

most vibrios have this as well as?

polar flagella as well as pili

type of pili in vibrio

toxin co-regulated pilus

cell wall

lipopolysaccharides consisting of lipid A (endotoxin), core polysaccharide, O polysaccharide side chain

V. cholerae 01 & 0139 produce?

cholera toxin

cholera toxin is associated w/?

endemics of cholera

what is serogroup 01 subdivided into

Inaba, Ogawa, Hikojima

biotypes

classical, El Tor

V. vulnificus & non-01 V. cholerae produce

acidic polysaccharide capsules

why are acidic polysaccharide capsules important

for disseminated disease

v.cholerae source of infection

water, food

v. cholerae clinical disease

gastroenteritis, bacteremia

v. cholerae virulence factor

cholera toxin, toxin co-regulated pilus surface binding site, chemotaxis protein, accessory cholera enterotoxin, neuraminidase, zonula occludens toxin

v. parahemolyticus source of infection

shellfish, seawater

v. parahemolyticus clinical disease

gastroenteritis, bacteremia, wound Ix

v. parahemolyticus virulence factor

kanagawa hemolysin

v. parahemolyticus biological effect

enterotoxin that induces chloride ion secretion

v. vulfinicus source of infection

shellfish, seawater

v. vulfinicus clincial disease

bacteremia, wound Ix

virulence factor of v. vulfinicus

polysaccharide capsule cytolysin, proteases, collagenase

v. vulfinicus biological effect

antiphagocytic, mediates tissue destruction

in chloera toxin-a complex a-b toxin, the b subunit binds to?

ganglioside GM1 receptors on intestinal epith. cells

in chloera toxin-a complex a-b toxin, the active part of A subunit interacts with?

G proteins —> hypersecretion of water & electrolytes

v.cholera is able to adhere to mucosal cell layer by means of

1. TCP encoded by TCP gene complex

2. CEP-encoded chemotaxis proteins

in the absence of chloera toxin, V. cholerae 01 can still produce?

significant diarrhea

how does v.cholerae 01 still produce significant diarrhea in abscence of cholera toxin?

the action of accessory enterotoxin & zonula occludens toxin

kanagawa hemolysin

thermolabile direct hemolysin (TDH)

v.parahemolyticus is an enterotoxin that…

induces chloride secretion by increasing intracellular calcium

v.parahemolyticus produces

beta-hemolytic colonies (kanagawa positive)

regarding v.vulficus, what happens in the presence of gastric acid?

organism rapidly degrades lysine producing alkaline byproducts

v.vulfinicus is able to evade host immune response by?

inducing macrophage apoptosis & avoid phagocytosis by expression of polysaccharide capsule

v. vulnficus possesses?

surface proteins

v. vulnficus possess surface proteins that?

mediate attachment to host cells & secrete cytolytic toxins that promote tissue necrosis

vibrio grow naturally in?

estuarine & marine environments

vibrio have the ability to?

survive & replicate in contaminated water w/ high salinity

vibrio can floruish in?

waters w/ chitinous shellfish

v. vulnificus most common cause

vibrio septicemia

v.vulnificus is responible for

severe wound infections w/ high incidence of fatal outcomes

toxigenic v. cholerae 01 causes

asymptomatic or severe, rapidly fatal diarrhea

manifestions of toxigenic v.cholerae 01 begins

2-3 days after ingestion of org w/abdurpt onset of watery diarrhea & vomiting

increased fluid loss with toxigenic v.cholerae 01 causes feces to become?

colorless & oderless, free of protein

what else does toxigenic v.cholerae 01 cause?

dehydration, painful muscle cramps, metabolic acidosis, cardiac arrhythmia, renal failure, death

v. parahemolyticus-gastroenteritis develops after…

2-72 hours incubation period

v. parahemolyticus-gastroenteritis 2-72 incubation with

explosive diarrhea; headahce, abd. cramps, N/V, low grade fever

v.vulnificus’s most common presentations

primary septicemia and rapidly progressivr wound infection

primary septicemia

after consumption of contaminated raw oysters

rapidly progressive wound infeciton

after exposure to contaminated seawater

in rapidly progressive wound infections, infections are severe in…

Pxs w/ hepatic dis., hematopoietic dis., chronic renal failure

microscopic exam of stools

rapid presumptive Dx

gram staining of?

wound specimen

immunoassays are used for

detection of cholera toxin or 01 & 0139 lipopolysaccharides

culture

sheep blood agar or chocolate agar

colonies are

medium to large, smooth, opaque & iridescent w/ greenish hue

in laboratory diagnosis, what kind of sucrose is present

thiosulfate cirate bile salt sucrose

sucrose-fermenting org. (V. cholerae)

yellow colonies

nonsucrose-fermenting org. (V. parahemolyticus)

green colonies

string test

0.5% Na deoxycholate lyses vibrio cells → release DNA which can be pulled up