Vibrio

Vibrio spp

gram negative curved rods and motile, and halophilic marine microbes, 2 chromosome species

v. cholerae

causes cholera

v. vulnificus

causes food borne infections from seafood and fulminant septicaemia and wound infectious

vibrio parahaemolyticus

causes food borne infections but a relatively mild disease so not a focus in our class

odd two component quorum sensing system

how is the pathogenic behavior of vibrio controlled

autoinducer

created when there is a population of vibrio, these will bind to the two component system sensor kinase and Deactivate the kinase

nitric oxide

the histidine kinase receptor sense ____ and at low cell densities the autoinducer levels are low and therefore the unbound recepors act as kinases to phosphorylate LuxU which turns on Qrr expression which activates AphA and individual behaviors

LuxR

protein that makes the group behavior which is blocked by Qrrs when there are no autoinducers bound to the sensor kinase

Filippo pacinni

discovered vibro cholera and took great notes after using great microscopy skills

John snow

described the method of transmission and spread of cholera by using epidemiology techniques (that he pioneered) and identified the point of origin of a cholera outbreak down to a street water pump

Robert Koch

discovered that vibrio cholera was the etiological agent of vibrio cholera and isolated the organism in a pure culture which was needed to prove his postulates

Freshwater

vibrio cholera thrives in ___ which is a deversion from other vibrio species, it forms biofilms and zooplankton

O1

epidemic v cholera group that has no capsule

O139

epidemic v cholera serogroup that usually has capsule

Small intestinal lining

v cholera colonizes the …

Watery diarrhea and dehydration (rice water stool)

major indicator of a v cholera infection, which is the reason for the high mortality rate for those untreated immediately (case fatality over 50%)

O antigen of the LPS

how are v cholera serogroups classified by ,,, whereby they differ on the amount of methylation they have

Cholera toxin

epidemic strains of v cholera produce the …

VPI 1

pathogenicity island of v cholera that encodes for the TCP which is essential for the CTX phage to colonize (and that brings the cholera toxin that is needed for pathogenesis) … this can also excsise itself from the chromosome forming a plasmid that can be transferred from cell to cell

Toxin coregulated pilius

this essential for colonization of v cholera in the human small intestine, facilitates the formation of microcolonies and serves as the receptor for the CTX phage

Cholera toxin

in v cholera this has an AB5 structure where the B binds to GM1 and A modified Gsalpha protein that leads to elevated cAMP levels which create an ion efflux that leads to the watery diahhrea

GM1

the receptor for the CT B subunit

Gsalpha

what does the CT A subunit modify

T2SS

what secretes the cholera and zonula occludens toxin

Zonula occuldens toxin

disrupts the tight junction proteins (claudins, occluding and ZO1) which increases permeability and allows fluid loss

PKC

what does the ZOT toxin activated leading to the phosphorylation and destabilization of the actin cytoskeleton

Rehydration therapy, Abs sometimes, Zinc supplements

how to treat vibrio cholera infections

Flesh eating bacteria

vibrio vulnificus is a _ and the leading cause of seafood related mortality

Acute gastroenteritis, necrotizing wound infections and invasive sepsis

v vulnificus diseases

MARTX toxin

forms pores in host cell membrane, subunits inactivate Rho GTPases and disrupt actin cytoskeleton and leads to cell rounding and apoptosis