Entero: E. coli (Ex2)

Question 1

Where does Enterobacteriacae normally reside?

What are the benefits of it being there?

Answer 1

• Resides in the GI tract
• Microbial antagonism
• Breakdown and absorption of food
• Waste processing
• Vitamin K production

Question 2

General features of Enterobacteriacae

gram, oxygen requirements, shape, oxidase

Answer 2

• Gram negative
• facultative anaerobe
• rods or coccobacilli
• oxidase negative

Question 3

What are Coliform Bacteria?

Name the three included

Answer 3

• Lactose positive bacteria
• E. coli
• Klehsiella
• Enterobacter

Question 4

General features of Escherichia coli

lactose, oxidase, motility, shape

Answer 4

• lactose positive
• oxidase negative
• motile
• rods

Question 5

Virulence Factors of E. coli

Answer 5

• capsule
• fimbrial and non-fimbrial adhesions
• endotoxin (LPS)
• enterotoxins
• cytotoxins
• siderophores

Question 6

What do these stand for?
ETEC
EHEC
VTEC/STEC
EPEC
RPEC
APEC
NTEC

Answer 6

ETEC - enterotoxigenic
EHEC - enterohemorrhagic
VTEC/STEC - verotoxigenic/shiga-like toxic
EPEC - enteropathic
RPEC - rabbit pathogenic
APEC - avian pathogenic
NTEC - nectrotoxigenic

Question 7

General Features of ETEC in pigs

symptoms, age affected, adhesion factors, enterotoxins

Answer 7

• watery diarrhea
• neonatal, weanlings
• adhesion factors: F4, F5, F6, F18, F41
• enterotoxins: LT, Sta, Stb, EAST1

Question 8

Adhesion factors of ETEC in pigs

Answer 8

F4 - on plasmids, specific receptors, mannose resistant, genes expressed at body temp, solely in pigs, neonates to weanlings
F5 - on plasmids, in pigs and bovines, mannose resistant, expression temp dependent, in young animals
F6 - extrachromosomal, neonatal
F41 - chromosomal, mannose resistant, pigs and bovines, freq with F5, rare, neonatal

Question 9

Describe LT enterotoxin in ETEC in pigs

Answer 9

• heat labile
• high molecular weight
• strong antigen
• Na absorption, Cl and HCO3 secretion
• activation of adenlyate cyclase

Question 10

Describe the heat stable enterotoxins in ETEC in pigs

Answer 10

• low molecular weight
• little antigen
• Sta: activation of guanylate cyclase, Na absorption, Cl and HCO3 secretion
• Stb: prostaglandin E2, secretion of water and electrolytes, stimulation of 5-H secretion
• EAST1: closely related to Sta

Question 11

Characteristics present at each age (neonatal, neonatal till 4 wks, weanling) in ETEC in pigs
(adhesion, enterotoxins, hemo/non)

Answer 11

Neonatal: F5, F6, F41; Sta, Stb; non-hemolytic
Neonatal - 4 wks: F4; LT, Sta, STb, EAST1; hemolytic
Weanling: F4, F18; LT, Sta, Stb, EAST1; hemolytic

Question 12

What are the causes of ETEC in pigs?

Answer 12

• increase infection pressure
• lowering of maternal immunity (MMA, first delivery, low birth weight, too many piglets)
• appearance of new type

Question 13

What are the symptoms of ETEC in pigs?

Answer 13

• remain drinking
• smelly feces
• dehydration
• diarrhea

Question 14

How do you diagnose ETEC in pigs?

Answer 14

• agglutination tests

- PCR

Question 15

Treatment of ETEC in pigs

Answer 15

• hydration

- antimicrobials

Question 16

Prevention of ETEC in pigs

Answer 16

• keep infection pressure low and maternal immunity high
• hygiene
• vaccination of sows
• selection of receptor free piglets

Question 17

Virulence factors of VTEC in pigs

Answer 17

• adhesion in small bowel: F18
• exotoxin: VT2e or Stx2e: media necrosis
• endotoxin: acute mortality

Question 18

What are the symptoms of VTEC in pigs?

Answer 18

• acute mortality in some
• diarrhea in some
• anorexia
• edema (hoarse voice, dyspnea, swollen eyelids, CNS)
• CNS signs

Question 19

How do you treat VTEC in pig?

Answer 19

• fasting to eliminate toxin
• increases intestinal peristalsis
• antimicrobial therapy

Question 20

How do you prevent VTEC in pigs?

Answer 20

• reduce stress
• feed restriction, increase fiber content, starter feed before weaning
• adaptation of intestinal flora (probiotics, organic acids, zinc oxide, antimicrobials, vaccination)
• selection of F18 receptor negative animals

Question 21

What are the symptoms of UTI E. coli in pigs?

Answer 21

• anorexia
• hematuria
• vaginal exudate
• general malaise

Question 22

What is MMA of PPDS?

What are the possible etiologies?

Answer 22

• Metritis-Mastitis-Agalactiae
• Post Partum Dysgalactiae Syndrome
• problem in milk production
• E: hereditary, hormonal, feed, infectious agents

Question 23

What are the symptoms of ETEC in bovines?

What age is affected?

Answer 23

• watery diarrhea leading to dehydration

- less than 3 days old, neonates

Question 24

Virulence factors of ETEC in bovines

Answer 24

• fimbriae (F5, F41, F17, CS31A)

- toxins (Sta and Stb)

Question 25

EPEC in pigs | symptoms, mechanisms, diagnosis

Answer 25

- diarrhea at weaning - attachment to enterocytes, effacement of microvilli - type 3 secretion system: injection of effector proteins into host cell - diagnose by isolation and PCR

Question 26

How to treat bovines with ETEC. | On milking farms?

Answer 26

- separate ill animals - hydration - antibiotics - NSAID (for shock) - MF: separate calves from mother, colostrum from another, antibiotics, vaccinate moms

Question 27

What age does VTEC (Edema disease) affect piglets?

Answer 27

post weaning

Question 28

What media necrosis by the toxin produced by VTEC in each chronicity of infect? (hyperacute, acute, chronic)

Answer 28

Hyperacute: enterorrhagia Acute: permeability of blood vessels leading to edema Chronic: intravascular coagulation

Question 29

Describe the pathogenesis of ETEC in bovines

Answer 29

- oral uptake - multiplication - enterotoxin production - secondary septicemia

Question 30

Diagnosis of ETEC in bovines

Answer 30

- ELISA | - culture+virulence factors (agglutination or PCR)

Question 31

EPEC and EHEC in bovines | age, virulence factors, symptom, location, therapy

Answer 31

- 1-8 weeks - muccoid diarrhea +/- blood - large intestine - antibiotics - EPEC: eae - EHEC: eae, VT, zoonotic

Question 32

Virulence factors of NTEC in bovines

Answer 32

- serum resistance - iron uptake - endotoxin - capsule - adhesion factors - CNF toxins

Question 33

How does the cow become infected with NTEC?

Answer 33

- per os via lymphoid tissues of head and throat or intestine - via umbilical cord - too little colostrum

Question 34

Symptoms of NTEC in bovines at each level of chronicity

Answer 34

Hyperacute: acute mortality, shock Acute: general symptoms, fast mortality Chronic: slow with organ localization

Question 35

How do you treat NTEC in bovines

Answer 35

- NSAID (shock) - antibiotics - gamma globulins

Question 36

Describe the pathogenesis of Neonatal colibacillosis (in avians)

Answer 36

- contamination of egg shell (shrinking of content and entrance of bacteria), neonatal contamination, manipulation of chicks - yolk rest infection - sepsis (then death), polyserositis, airsac, pericad (growth retardation)