Lab 6- Escherichia

Question 1

Discovered by?

Answer 1

Theodor Escherich

Paediatrician

Question 2

Habitat

Answer 2

Gut, aerobic, faculative anaerobic gut flora in mammals and birds

Question 3

Morphology

Answer 3

2-3 um rod

Capsule, flagella, fimbria

Question 4

Staining

Answer 4

Gram negative

Question 5

Characteristics of flagella ?

Answer 5

Long protein tubes, tumbling motility

Question 6

Culture

Answer 6

Selective and differential media

Low selectivity:

• Drigalski (crystal violet, lactose, litmus)
• Macconkey (crystal violet, bile salts, lactose, neutral red)
• eosin, lactose, methylene blue

Medium selective:

• brilliant green, lactose, phenol red
• DC (deoxycholate-citrate, lactose, neutral red)

Seen with naked eye:

Capsulated (calf origin) = septicaemia in calf, Mucoid colonies

Haemolytic (swine origin)= on blood agar, pathogenic strains

Question 7

Lactose ?

Answer 7

Positive

Question 8

Mannitol

Answer 8

Positive

Question 9

Indol production

Answer 9

Positive

Question 10

Methyl red

Answer 10

Positive

Question 11

Voges-proskauer

Answer 11

Negative

Question 12

Citrate utilization

Answer 12

Negative

Question 13

Urease

Answer 13

Negative

Question 14

H2S

Answer 14

Negative

Question 15

Phenylalanine deaminase

Answer 15

Negative

Question 16

Antigens

Answer 16

O type = 174
K type= 80
F type= 19
H=57

Fimbria antigens most important

F1= common 
F2+3= human 
F4+6+18= pig
F5+17+41= calves 
F5=lamb
F7-16= UTI, human and poultry

Question 17

Resistance

Answer 17

Medium

Can survive for weeks in environment

Question 18

Pathogenicity

Answer 18

Saprophytes c faculative pathogenic

Question 19

Causes what in cattle?

Answer 19

Calf coli-diarrhea
Calf coli-septicaemia
Cow= mastitis

Question 20

Causes what in swine?

Answer 20

Coli-diarrhea in neonatal piglets

Weaned piglets= coli-diarrhea, oedema disease
Sow= mastitis, metritis

Question 21

Causes what in lamb/kid?

Answer 21

Coli-diarrhea (neonatal)

Question 22

Causes what in rabbit?

Answer 22

Diarrhea

Question 23

Causes what in poultry?

Answer 23

Day old chicken = septicaemia

Chicken= septicaemia, respiratory disease 
Older= lesions in organs (airsacculitis, peritonitis, coli-granulomatosis)

Question 24

Causes what in foal, dog, cat, Fox, nutria, chinchilla?

Answer 24

Coli-diarrhea, septicaemia

Question 25

Causes what in human ?

Answer 25

Neonatal enteretitis, septicaemia, urogential infections, enteritis, haemorrhagic enterocolitis

Question 26

Pathogenic e. Coli strains

Answer 26

- Enteropathogenic or attaching/effacing (intimin) - Enterotoxic strains (enterotoxin) - Verotoxigenic - Neurotoxic - Enteroinvasive - Enteroadhensive-aggregative - Enteroheaemorrhagic - Septicaemic

Question 27

Characteristics of enteropathogenic?

Answer 27

Intimin required for colonization Destruction of microvilli, atrophy and shedding of enterocytes Maldig. + malabs. Diarrhea in piglets, lambs and pups

Question 28

Characteristics of Enterotoxigenic

Answer 28

``` F4 = pig F5= calves, lambs ``` ``` LT= induce hypersecration - heat labile ST= reduces abs. - heat stabile ``` Diarrhea in neonatal piglets, calves and lambs Post weaning diarrhea in pigs

Question 29

Characteristics of verotoxigenic

Answer 29

Bind to erythrocytes Damage to vascular use in intestine and other locations Oedema disease in weaned piglets Haemorrhagic enterocolitis in calves Post weaning diarrhea in pigs Haemorrhagic colitis-haemolytic uraemic syndrome in human (lethal)

Question 30

Characteristics of necrotoxic

Answer 30

Bind to erythrocytes Cytotoxic necrotizing factors Damage to rbc and blood vessels Haemorrhagic colitis in cattle Enterocolitis in piglets and calves Diarrhea in rabbits Dysentery in horses

Question 31

characteristics of Septicaemic

Answer 31

Endotoxin effect Invasion of blood streams Septicaemia in birds Colispeticaemia in calves, piglets, pups and chickens Watery mouth in lambs Arthritis, meningitis

Question 32

Characteristics of uropathogenic

Answer 32

Adhesions required for colonization Endotoxins and exotoxins: local reactions Cystitis in bitches

Question 33

Opportunistic strains

Answer 33

Mastitis in cattle and sows Pyometra in bitches and queens Metritis Omphalitis in calves, lambs and chicks