Lab 6- Escherichia Flashcards
Discovered by?
Theodor Escherich
Paediatrician
Habitat
Gut, aerobic, faculative anaerobic gut flora in mammals and birds
Morphology
2-3 um rod
Capsule, flagella, fimbria
Staining
Gram negative
Characteristics of flagella ?
Long protein tubes, tumbling motility
Culture
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
Lactose ?
Positive
Mannitol
Positive
Indol production
Positive
Methyl red
Positive
Voges-proskauer
Negative
Citrate utilization
Negative
Urease
Negative
H2S
Negative
Phenylalanine deaminase
Negative
Antigens
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
Resistance
Medium
Can survive for weeks in environment
Pathogenicity
Saprophytes c faculative pathogenic
Causes what in cattle?
Calf coli-diarrhea
Calf coli-septicaemia
Cow= mastitis
Causes what in swine?
Coli-diarrhea in neonatal piglets
Weaned piglets= coli-diarrhea, oedema disease
Sow= mastitis, metritis
Causes what in lamb/kid?
Coli-diarrhea (neonatal)
Causes what in rabbit?
Diarrhea
Causes what in poultry?
Day old chicken = septicaemia
Chicken= septicaemia, respiratory disease Older= lesions in organs (airsacculitis, peritonitis, coli-granulomatosis)
Causes what in foal, dog, cat, Fox, nutria, chinchilla?
Coli-diarrhea, septicaemia
Causes what in human ?
Neonatal enteretitis, septicaemia, urogential infections, enteritis, haemorrhagic enterocolitis
Pathogenic e. Coli strains
- Enteropathogenic or attaching/effacing (intimin)
- Enterotoxic strains (enterotoxin)
- Verotoxigenic
- Neurotoxic
- Enteroinvasive
- Enteroadhensive-aggregative
- Enteroheaemorrhagic
- Septicaemic
Characteristics of enteropathogenic?
Intimin required for colonization
Destruction of microvilli, atrophy and shedding of enterocytes
Maldig. + malabs.
Diarrhea in piglets, lambs and pups
Characteristics of Enterotoxigenic
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
Characteristics of verotoxigenic
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)
Characteristics of necrotoxic
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
characteristics of Septicaemic
Endotoxin effect
Invasion of blood streams
Septicaemia in birds
Colispeticaemia in calves, piglets, pups and chickens
Watery mouth in lambs
Arthritis, meningitis
Characteristics of uropathogenic
Adhesions required for colonization
Endotoxins and exotoxins: local reactions
Cystitis in bitches
Opportunistic strains
Mastitis in cattle and sows
Pyometra in bitches and queens
Metritis
Omphalitis in calves, lambs and chicks
