Enterobacteriaceace; Escherichia

Question 1

Theodor Escherich?

Answer 1

• German paediatrician

- 1857-1911

Question 2

Habitat

Answer 2

Gut, aerobic, facultative anaerobic in gut flora

Question 3

Morphology

Answer 3

• 2-3 um rods
• Capsule
• Flagella (hair like tubes, can attach to target cells)
• Fimbria (hair like tubes, can attach to target cells)

Question 4

Staining

Answer 4

Gram-negative

Question 5

Culture

Answer 5

• Simple, not fastidious
• Selective and differential media
• Fermentation of lactose -> acidic pH
• Capsulated (calf origin) strains isolated from calves
• Haemolytic (swine origin) strains isolated from pigs

Question 6

Biochemical characteristics; Lactose

Answer 6

+

Question 7

Biochemical characteristics; Mannitol

Answer 7

+

Question 8

Biochemical characteristics; Indol production (from tryptophan)

Answer 8

+

Question 9

Biochemical characteristics; Methyl red

Answer 9

+

Question 10

Biochemical characteristics; Voges-Proskauer

Answer 10

-

Question 11

Biochemical characteristics; Citrate utilization

Answer 11

-

Question 12

Biochemical characteristics; Urease

Answer 12

-

Question 13

Biochemical characteristics; H2S

Answer 13

-

Question 14

Biochemical characteristics; Phenylalanine deaminase

Answer 14

-

Question 15

Antigens

Answer 15

• O: type specific -> 174 types
• K: heat stabile(A) and heat labile(L) -> 80 types
• F: virulence factors, fimbria antigens -> 19 types. F1 (common fimbria), F2 and F3 (human), F4-F6-F18 (pig), F5-F17-F41 (cattle, calves), F5 (lamb), F7-F16 (urinary tract infection; human, poultry)
• H -> 57 types

Question 16

Resistance

Answer 16

Medium, not spore forming

Question 17

Detection of antigens

Answer 17

Latex agglutination

Question 18

Pathogenicity; saprophyte and facultative pathogenic -> Cattle

Answer 18

• Calf coli-diarrhea (neonatal)
• Calf coli-septicaemia
• Cow mastitis

Question 19

Pathogenicity; saprophyte and facultative pathogenic -> Swine

Answer 19

• Coli-diarrhea of neonatal pigs
• Weaned piglets: coli-diarrhea, oedema disease
• Sow: mastitis

Question 20

Pathogenicity; saprophyte and facultative pathogenic -> Lamb, kid

Answer 20

• Coli-diarrhea (neonatal),

- Watery mouth

Question 21

Pathogenicity; saprophyte and facultative pathogenic -> Rabbit

Answer 21

• Diarrhea

Question 22

Pathogenicity; saprophyte and facultative pathogenic -> Poultry

Answer 22

• Connected with age
• Day old: septicaemia
• Chicken: septicaemia, resp disease
• Older: lesions in organs (airsacculitis, peritonitis, coli-granulomatosis)

Question 23

Pathogenicity; saprophyte and facultative pathogenic -> Foal, dog, cat, mink, fox, nutria, chinchilla

Answer 23

• Coli-diarrhea

- Septicaemia

Question 24

Pathogenicity; saprophyte and facultative pathogenic -> Human

Answer 24

• Neonatal enteritis
• Septicaemia
• Urogenital infections
• Enteritis
• Haemorrhagic enterocolitis

Question 25

Pathogenic E. Coli strains; enteropathogenic or attaching/effacin

Answer 25

(EPEC or AEEC) strains - Intimin-virulence factor helps adhesion to enterocytes -> damaged microvilli -> diarrhea - Destruction of microvilli, atrophy (wasting) and shedding of enterocytes - Maldigestion, malabsorption - Diarrhea in piglets, lambs and puppies

Question 26

Pathogenic E. Coli strains; enterotoxigenic strains

Answer 26

(ETEC) - Enterotoxin: LT 88.000D, ST 1.500-2.000 D. LT -> induce hypersecretion of water into gut, ST -> reduces absorption (enterocytes maintain normal structure) --> Diarrhea - Adhesive factors F4: pigs, F5: calves, lambs - Enterotoxin: LT 88.000D, ST 1.500-2.000 D - Diarrhea in neonatal piglets, calves, lambs

Question 27

Pathogenic E. Coli strains; verotoxigenic

Answer 27

(VTEC) - Verotoxins: VT1, VT2, VT2e - Bind to erythrocytes - Damage to vasculature in intestine and other locations, - First found in cell line of monkey - Inhibits protein synthesis or the endothelial cells -> hemorrhages - Oedema diseases in weaned piglets - Post-weaning diarrhea in pigs - Haemorrhagic enterocolitis in calves - Haemorrhagic colitis - haemolytic uraemic syndrome in human

Question 28

Pathogenic E. Coli strains; necrotoxic

Answer 28

- Cytotoxic necrotic factors: CNF1, CNF2 strains - Bind to erythrocytes, damage to erythrocytes and blood vessels - Haemorrhagic colitis in cattle - Enterocolitis in piglets and calves - Diarrhea in rabbits - Dysentery in horses

Question 29

Pathogenic E. Coli strains; enteroinvasive

Answer 29

- Can enter into mucous membranes of large intestine - Necrosis - Diarrhea

Question 30

Pathogenic E. Coli strains; enteroadhesive-aggregative

Answer 30

not too important

Question 31

Pathogenic E. Coli strains; enterohaemorrhagic

Answer 31

O157-H7

Question 32

Pathogenic E. Coli strains; septicaemic strains

Answer 32

yes, they exist

Question 33

Septicaemic E. coli

Answer 33

- Invasion of blood streams, survive in blood - Endotoxin effect - Calves, piglets, pups, chickens: colisepticaemia - Lambs: watery mouth - Arthritis, meningitis

Question 34

uropathogenic E. coli

Answer 34

- Adhesins required for colonization - Endotoxins and exotoxins: local reactions - Bitches: cystitis

Question 35

Opportunistic E. coli strains

Answer 35

- Cattle and sows: mastitis - Bitches and queens: pyometra - Metritis - Calves, lambs, chickens: omphalitis (inflammation of umbilical cord