Pathogenic E. coli and Diarrhea Mechanisms

A set of vocabulary flashcards covering the economic impact, transmission, infection mechanisms, and physiological effects of Pathogenic E. coli and Shiga toxins.

Enterohaemorrhagic E. coli (EHEC) O157:H7

A pathogen first isolated in Argentina in $1971$ that carries an infective dose of $10-100$ organisms and causes symptoms like bloody diarrhea and abdominal cramps.

Hemolytic-uremic syndrome (HUS)

A condition that can result from an EHEC infection which may lead to kidney failure.

Effectors

Bacterially derived proteins delivered into a host cell to modify the cytoskeleton, organellar functions, cellular structures, or signaling pathways.

Type III secretion system

Also known as the needle apparatus, it is a method used by G-pathogens to deliver effectors directly into the host cell cytoplasm.

Pedestals

A hallmark of pathogenic E. coli disease formed when the pathogen collapses host cell microvilli, which allowed the bacteria to surf on infected cells.

Shiga Toxin

A specific host site exotoxin that targets the intestine; it was first identified by Kiyoshi Shiga in Shigella dysenteriae.

Dissemination

The process by which a pathogen causes diarrhea in order to spread itself into the environment.

Enteric nervous system

The nervous system of the intestine that E. coli can affect via serotonin functions to generate diarrhea.

Aquaporins (AQP2 and AQP3)

Water channels that are ripped out of the host cell membrane by bacterial effectors like EspF and EspG to increase water in the lumen.

Tight Junctions

Intercellular structures that are breached during E. coli infection by effector proteins such as EspF, EspG, and Map.

Diarrhea (Bacterial-induced)

A physiological state where GI motility increases and water content in the material exceeds $85\%$.