Sketchy Microbiology: Escherichia coli (E. Coli), ETEC, EHEC

E Cola Dinner — Escherichia coli (E. Coli), ETEC, EHEC

What are the most common (Diarrhea causing) types of E.Coli?

1. Enteropathogenic E. Coli (EPEC)

2. Enterohaemorrhagic E. Coli (EHEC)

   1. Shiga (Vero) toxin producing E. Coli (STEC or VTEC)

3. Enterotoxigenic E. Coli (ETEC)

4. Enteroaggregative E. Coli (EAEC)

5. Enteroinvasive E. Coli (EIEC)

Hint: Color

Red Theme – Gram Negative Bacilli (Rod)

As a Gram Neg Rod; we know it has

• Lipopolysaccharide (LPS) → O Antigen

• Endotoxin

Milk Container — E. Coli Ferments lactose

(Grows pink on MacConkey’s Agar)

Hint: Capsule / No Capsule

Capsule — E. Coli is Encapsulated

(Facultative Anaerobe, Oxidase Negative, Green sheen on EMB)

Hint: K Cake

K Cake — K Antigen (in capsule) and H Antigen (in Flagellum)

(Remember; O Antigen always there)

According to lecture, what are the virulence factors E. Coli has?

• Surface proteins

• Capsule (K Antigen)

• Fimbriae (Type 1, P, M, S)

• Flagellum (H Antigen)

• Cytotoxines

• Siderophores

Green Coasters — Metallic green sheen of E. Coli on EMB Agar

Cat — E. Coli is Catalase Positive

Long “fimbriae bow” in girl’s hair — fimbriae (a virulence factor) are necessary for E. Coli to cause UTI

#1 UTI Bladder Drink — E. Coli causes 50 - 80% of all UTIs

(Mainly from ascending infections originating from colon)

Red Strawberry Milkshake - E.coli leading cause of gram neg sepsis by LPS endotoxin in outer cell membrane

(Remember; we call Pyelonephritis ←→ “Urosepsis”)

Hint: Kid + K Cake

Meningitis Helmet — Causes neonatal meningitis due to K1 capsular antigen

According to lecture, what is unique about EPEC’s adhesion?

EPEC (Enteropathogenic E. Coli) adheres to the microvilli in the gut via tight adhesion to the Tir receptor which makes polymerized / aggregated actin.

This makes the microvilli disappear ( effacement).

AE — Attaching — Effacing Effect

Hint: “Left Side of Image”

E. Cola Burger — EHEC (Enterohaemorrhagic E. Coli)

Burger — EHEC Most Commonly caused by eating undercooked meat (especially hamburgers)

Bloody Ketchup — EHEC causes bloody diarrhea

(kid sitting on red stool ←→ Bloody stool)

Sorbitol Free Coke — EHEC does NOT ferment sorbitol

Gorilla toy — EHEC Toxin inhibits 60s ribosomes

EHEC Toxin ←same→ Shiga Toxin (Becuase EHEC is also called Shiga Toxin producing E. Coli)

Blown up balloon — Shiga-like Toxin can cause hemolytic uremic syndrome

Shiga-like toxin damages the endothelial cells of the glomerular capillaries. Damaged endothelial lining causes platelets to adhere, decreasing platelet count, causing thrombocytopenia. These platelet clumps will hemolize RBCs

Balloon = hemolysis

Straw = glomerulus

Plates = platelet aggregation

“E. Coli Burger only $1.57” — O157:H7 Antigen is most commonly associated with EHEC outbreaks

Water Truck — ETEC (Enterotoxigenic E. Coli)

Water Jugs — ETEC is transmitted via water sources

From Mexico — ETEC commonly called “Traveler’s Diarrhea”

“eL Agua” — Heat Labile toxin produces cAMP

“San Gabriel” — Stable produces cGMP

Brown Stool w/ water — ETEC causes watery Diarrhea