ESCHERICHIA

Question 1

What kind of pathogen is Escherichia (E.coli)?

Answer 1

Bacteria

Question 2

Is Escherichia (E.coli) gram positive or gram negative?

Answer 2

Gram negative

Question 3

What would Escherichia (E.coli) look like on a microscope slide?

Answer 3

Pink rods

Question 4

Is Escherichia (E.coli) aerobic or anaerobic? Does it form spores?

Answer 4

Aerobic
It does not form spores

Question 5

What is the significance of Escherichia (E.coli) being a motile bacteria?

Answer 5

The bacteria can move on its own, escape unfavorable conditions and exploit new areas where it can survive and continue to be pathogenic

Question 6

What are some strains of Escherichia (E.coli)?

Answer 6

-Enterinopathogenic E. coli (EPEC)
-Enteroinvasive E. coli (EIEC)
-Enterotoxigenic E.coli (ETEC)
-Enteroaggretive E. coli (EAEC)
-Shiga toxin producing E. coli (STEC)

PITAS like pita bread :)
P-athogenic
I-nvasive
T-oxigenic
A-ggretive
S-higa toxin

Regular E.coli: normally found in gut flora

Question 7

How is ETEC transmitted?

Answer 7

-Food and water borne

Question 8

What is the pathogenesis of ETEC?

Answer 8

Enterotoxins

Question 9

How would an ETEC infection present?

Answer 9

Traveler’s diarrhea

Question 10

How is STEC transmitted?

Answer 10

-Food and water bornre
-Person to person
-Animals

Question 11

What is the pathogenesis of STEC?

Answer 11

-Shiga toxin
*Strain 0157:H7 from restaurants!

Question 12

How would a STEC infection present?

Answer 12

Hemolyti urea syndrome: Fever, Thrombocytopenia (low platelet count), Possible renal Failure

-Hemorrhagic colitis: severe cramping, initially diarrhea is watery and then grossly bloody

Question 13

How is EPEC transmitted?

Answer 13

Person to person

Question 14

What is the pathogenesis of EPEC?

Answer 14

Bacteria adheres to intestinal lining (forms adhesions) will cause intestinal leaking (malabsorption)

Question 15

How does a EPEC infection present?

Answer 15

Watery diarrhea

Question 16

How is EIEC tansmitted?

Answer 16

-Food and water borne
-Person to person
-Travelers

Question 17

What is the pathogenesis of EIEC?

Answer 17

DIRECT INVASION of colon cells

Question 18

How would an EIEC infection present?

Answer 18

Dysentery syndrome similar to Shigella bacteria
-Colitis (inflamed colon)
-Inflammation

Question 19

How is EAEC tansmitted?

Answer 19

-Food and water borne
-Person to person
-Travelers

Question 20

What is the pathogenesis of EAEC?

Answer 20

Diffuse aderence and replication, yet not invasive (doesn’t normally spread)

Question 21

How would an EAEC infection present?

Answer 21

-Travelers diarrhea
-Persistent diarrhea
-Symptoms can last MONTHS

Question 22

Due to the wide spectrum of the disease, numerous strains of E.coli may also cause what infections?

Answer 22

-UTI (most common in women)
-Diarrheal illness
-Intra-abdominal infection
-Neonatal meningitis
-Bacteremia
-Hospital acquired (nosocomial) pneumonia
-Surgical wound infections

Question 23

What is the treatment for infections caused by these strains of E.coli? What does it depend on?

Answer 23

Depends on severity/symptoms of infection

-Usually self limiting/will resolve on its own:
Hydration, supportive and symptomatic treatment

-Severe non-bloody diarrhea: Ciprofloxacin, Bactrim, Rixaximin

-Bloody diarrhea: NO ANTIBIOTICS, this will make it worse

Question 24

What two E.coli types can cause travelers diarrhea?

Answer 24

ETEC and EAEC

(Think: TA = time of arrival, vacation, traveling!)

Question 25

What kind of infection would be caused by normal gut flora E.coli?

Answer 25

Hospital acquired (nosocomial) Pneumonia: association with being on a vent, common in nursing homes and hospitals Neonatal meningitis: highest risk in first month of life (along with Group B strep) UTI (spectrum): -uncomplicated healthy patients (98%) -Kidney infection (pyelonephritis), catheter associated, urosepsis: tachy or low BP, shock syndrome symptoms (2%) Intra-abdominal infections: Any barriers of organs, if disrupted, can be affected -intraperitoneal abcess (collection of pus in abdomen) -Peritonitits: inflammation of lining in abdomen (usually during a surgery)

Question 26

How can a normal gut flora E.coli UTI be treated?

Answer 26

-Macrobid, Bactrim, Quinolones -3rd generation Cephalosporins for complicated cystitis

Question 27

How can a normal gut flora E.coli pyelonephritis infection be treated?

Answer 27

IV Ceftriaxone, Ciprofloxacin, Bactrim ***MACROBID WILL NOT WORK

Question 28

How can a normal gut flora E.coli Intra-abdominal infection be treated?

Answer 28

-3rd/4th gen Cephalosporins -Quinolones -Ceftriaxone (Zosyn)

Question 29

What does normal gut flora E.coli have an increasing resistance to?

Answer 29

UNASYN (ampicillin and sulbactam combo)