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DISEASES CAUSED BY

ESCHERICHIA COLI

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Diseases caused by Escherichia coli

Aetiology:

• Escherichia coli

• Enterobacteriaceae family

• Gram-negative

• lactose positive

• antigens:

• O: LPS (181), endotoxin

• K: polysaccharide (60)

• H: protein (53)

• F: protein (30)

• F1-F18, F41, etc.2

• normal inhabitant of the large intestine

• normal flora, vitamin production, activation of the immune system

• pathogenicity

• mainly saprophyte,

• some facultative pathogenic strains

• virulence factors

• capsule

• endotoxin

• adhesins

• toxins

• invasive ability

• ability of survival in blood

• genetic variability3

• virulence factors

• adhezins:

• fimbria

• human: F2, F3

• calves: F5, F17, F41

• pigs: F4, F6, F18

• urogenital: F7-F16

• outer membrane proteins

• intimin

• fibronectine receptors

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• virulence factors

• toxins

oenterotoxins

� LT: cAMP ↑↑↑↑

� ST:, cGMP ↑↑↑↑ (dehydration, metabolic acidosis)

ocytotoxins

� verotoxins

• SLT / VT1, VT2:

• inhibition of protein synthesis: endothel damage, ne crosis

� cytotoxic necrotic factor (CNF)

� cytolethal distending toxin (CDT): urogenital, extra intestinal

� alpha-haemolysin: pore forming toxin

• invasive ability

• survival in the blood (siderophors) 5

Pathotypes of E. coli I. Enteric

• Enterotoxigenic (ETEC)

• diarrhoea in suckling animals, newborn children, tr avellers

• enterotoxins, fimbria

• Enteropathogenic (EPEC)

• dyspepsia of newborns

• intimin, damage of microvilli

• Enterohaemorrhagic /Verotoxigenic (EHEC/VTEC)

• haemorrhagic colitis, haemolytic-uraemic syndrome

• intimin, verotoxins

• Enteroinvasive (EIEC)

• humans, dysentery-like

• Enteroadhesive-aggregative (EAEC): mild enteritis h umans

• Combined types: EHEC/EAEC Germany 2011 O104:H4 6

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Enterotoxigenic and enteropathogenic E. coli

strains (Dr. B. Nagy)

Pathotypes of E. coli II.

Extra intestinal

• Urogenital

• adhesin (F7-16),

• toxins: CNF, CDT, alpha-haemolysin

• Septicaemia, meningitis

• newborn children, old people, immune compromised pe ople

• colicin-V plasmid, alpha-haemolysin

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Diseases of animals caused by E. coli

• Enteric diseases

• calves (ETEC, VTEC)

• piglets (ETEC, VTEC, EPEC)

• rabbits (EPEC)

• dogs, cats (ETEC, VTEC, EPEC)

• Septicaemic diseases

• calves

• poultry

• Urinary tract infection, mastitis

• cows,

• sows: MMA

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Epidemiology

• infection

• faeces, feed, water contaminated with faeces

• egg: germinative

• predisposing factors

• insufficient feeding of pregnant cows, weak calves

• insufficient colostrum supply

• overcrowding

• stable (temperature, humidity, etc.)

• nutritional deficiencies

• hygiene problems

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Pathogenesis

• infection

• asymptomatic presence in the gut

• predisposing factors

• replication in gut

• production of enterotoxins

• diarrhoea

• production of verotoxins

• haemorrhages, oedema

• septicaemia

• endotoxin effect

Diagnosis

• epidemiology – clinical signs – post mortem lesions

• bacteriology:

• isolation and identification of E. coli: pure culture

• identification of the serotype (O-K-H-F)

• identification of the virulence factors

• adhesins (agglutination, PCR)

• toxins (isolated gut test, PCR)

• examination of antibiotic susceptibility

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Treatment

• enteric diseases

• per os antibiotics

• polymyxins, quinolons, aminoglycosides, broad spect rum

ββββ-lactame antibiotics: amoxicillin, cephalosporins

• rehydration

• septicaemia

• parenteral

• generally late

• mastitis

• quinolons, aminoglycosides

• antibiotic resistance

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Prevention

• predisposing factors

• correct feeding of pregnant animals

• good nutrition and management

• hygiene

• specific prevention

• colostrum

• supply in time

• quality (presence of appropriate antibodies)

• quantity

• vaccination

• mainly in the case of neonatal diseases

• probiotics: Lactobacillus, Enterococcus, Bifidobacterium

• prebiotics: feed additives 14

DISEASES CAUSED BY E. COLI IN CATTLE

1. Coli septicaemia of calves

2. Coli diarrhoea of calves

3. Calf dysentery

4. Mastitis

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COLI SEPTICAEMIA OF CALVES

Occurrence

• sporadic

Aetiology

• septic (invasive) E. coli strains (O78:K80), F17

• no toxin production

• survival in blood (siderophors, iron binding protei ns)

Epidemiology

• first week of life

• predisposing factors

• hypo-gammaglubulinaemia (agamma-globulinaemia)

• navel infection

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Pathogenesis

• infection

• per os

• umbilical

• pharynx lymphoid tissues ( →→→→ blood)

• gut ( →→→→ blood)

• septicaemia

• endotoxin effect

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Clinical signs

• fever , anorexia, depression

• weakness

• diarrhoea is not typical

• meningitis, pneumonia

• dies within 1-2 days

Post mortem lesions

• haemorrhages

• enlarged lymph nodes

• pericarditis, perihepatitis (fibrinous)

• peritonitis

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Diagnosis

• epidemiology – clinical signs – post mortem lesions

• isolation of the agent from

• parenchymal organs

• blood

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Treatment

• parenteral antibiotics

• generally late

Prevention

• hygiene

• colostrum

• optimal nutrition of the pregnant cows

• check the level of immunoglobulins in newborn calve s

• disinfection of the navel

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COLI DIARRHOEA OF CALVES

Occurrence

• widespread

Aetiology

• enterotoxigenic E. coli

• fimbria: F5, F17, F41

• ST toxin

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Epidemiology

• more frequent in large scale farms

• at the end of the winter

• 2-4-day-old

• predisposing factors

• overcrowing

• cold, wet stable

• colostrum supply (but cannot completely prevent)

• insufficient nutrition of cowsPathogenesis

• per os infection

• colonisation, toxin production

• diarrhoea, fluid loss

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Clinical signs

• no fever

• anorexia, depression

• diarrhoea (yellow, stinking)

• dehydration

• in case of sufficient colostrum supply clinical sign s are milder

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Post mortem lesions

• exsiccosis

• stomach, gut filled

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Coli diarrhoea in calf

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Diagnosis

• epidemiology – clinical signs – post mortem lesions

• isolation of the agent

• detection of the virulence factors

• detection of fimbriae

• detection of enterotoxin

• serotyping

• differential diagnosis

• rotavirus

• coronavirus

• cryptosporidiosis

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Treatment

• per os antibiotics

• rehydration

Prevention

• hygiene, disinfection

• good nutrition of the pregnant cows

• colostrum

• isolation (individual cages, moving)

• vaccination: cows

• bacterins

• inactivated toxin

• combined vaccines

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CALF DYSENTERY CAUSED BY VEROTOXIGENIC E. COLI

Occurrence

• sporadic

Aetiology

• verotoxigenic E. coli (VTEC/EHEC)

• VT1, VT2

• O157:H7

Epidemiology

• subclinical infection is common

• cows do not show signs but carry the agent (1-3%)

• carriage by calves 5-15%

• public health importance 28

Pathogenesis

• per os infection

• small amount of bacteria is enough

• replication in the large intestine

• damage of the microvilli

• production of verotoxins (VT1, VT2)

Clinical signs

• 2-8 weeks of age

• chronic diarrhoea (brownish, reddish, cream-like)

• can recover spontaneously

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Post mortem lesions

• large intestine

• hyperaemia

• haemorrhages

Diagnosis

• bacterium isolation, serotyping

• detection of the toxin

• differential diagnosis

• coccidiosis

• coronavirus

• cryptosporidiosis

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Treatment

• oral bacteriostatic antibiotics

• bactericid ones can help release of the toxin

• rehydration

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DISEASES CAUSED BY E. COLI IN SWINE

• Coli diarrhoea of newborn piglets

• Coli diarrhoea of weaned piglets

• Oedema disease

• Other diseases caused by E. coli

• coli-septicaemia

• mastitis, metritis,

• cystitis, pyelonephritis

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COLI DIARRHOEA OF NEWBORN PIGLETS

Occurrence

• worldwide

• large scale farms

Aetiology

• enterotoxigenic E. coli

• virulence factors

• fimbria: F4, F6, (F5)

• enterotoxins: LT, STa, STb

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Epidemiology

• appears in different litters

• more frequent in litters of first farrowing sows

• some litters are resistant

• absence of receptors, dominant inheritance

• it can be seen even in the case of good colostrum s upply

• predisposing factors:

• age,

• overcrowding, cold, wet stable, hygiene problems

• nutritional deficiencies,

• low body weight

• 0-10 days of age

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Pathogenesis

• per os infection

• replication in the gut

• adhesion by fimbria

• toxin production

• diarrhoea, dehydration

• shedding in faeces

• susceptibility is decreasing with age

• weaker binding to older epithelial cells

• decreased susceptibility of epithelial cells to ent erotoxins

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Clinical signs

• good appetite

• depression

• no fever

• diarrhoea (yellow faeces)

• dehydration

Post mortem lesions

• stomach filled with clotted milk

• gastric mucosa is reddish

• gut is flaccid

Coli diarrhoea (NADIS)36

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Coli diarrhoea of suckling piglets37

Coli diarrhoea, full stomach (NADIS)

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Diagnosis

• epidemiology – clinical signs – post mortem lesions

• isolation of the agent: gut, mesenthelial lymph nodes , (organs)

• identification of the virulence factors

• differential diagnosis

• necrotic enteritis of suckling piglets

• TGE

• rotavirus

• coccidium

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Treatment

• oral antibiotics

• whole litter has to be treated

• rehydration

Prevention

• hygiene

• predisposing factors

• colostrum

• mixing first farrowing and old sows before farrowin g

• all-in-all-out

• vaccination

• inactivated strains with fimbria

• inactivated LT

• pregnant sows have to be vaccinated 40

COLI DIARRHOEA OF WEANED PIGLETS

Occurrence

• worldwide

Aetiology

• ETEC strains

• virulence factors:

• fimbria

• F4,

• F18ac (susceptibility is increasing with age)

• sometimes VTEC and CNF producing strains

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Epidemiology

• intensive feeding

• predisposing factors

• stress caused by weaning

• nutrition: sudden change of the diet, overeating

• transportation, reallocation

• slow adaptation of the gastrointestinal tract

• viruses: rota, corona, calici

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Pathogenesis

• the causative agent is present in the gut

• increased susceptibility to F18ac fimbria

• changes in the gut flora

• shortening of the microvilli

• overeating (high protein)

• insufficient production of enzymes

• slow peristaltic movement

• gastroenteritis

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Clinical signs

• 1-2 weeks after weaning

• diarrhoea

• smell: undigested protein

• VTEC, CNF-producing strains

• haemorrhagic faeces

• uneven stock

• decreased weight gain

Post mortem lesions

• gastritis, enteritis

• mesentherial lymph nodes enlarged

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Coli-diarrhoea of weaned piglets

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Diagnosis

• epidemiology – clinical signs – post mortem lesions

• bacterium isolation

• characterisation of the bacterium

• characterisation of virulence factors

Treatment

• decreased portion

• increased fibre content

• antibiotics in the water

• rehydration

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Prevention

• improved hygiene

• decreased portion, increased fibre content

• gradual change of diet

• probiotics, prebiotics

• vaccines

• fimbriated strains

• attenuated strains

• limited effect, they are generally not used

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OEDEMA DISEASE

Occurrence

• mainly small farms

• sometimes large farms, too

Aetiology

• verotoxigenic E. coli strains

• virulence factors

• verotoxin (VT2v)

• F18ab fimbria

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Epidemiology

• sporadic

• mainly 1-2 weeks after weaning

• predisposing factors:

• weaning

• sudden change of diet

• high protein content of the food

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Pathogenesis

• VTEC replication in the gut

• toxin production

• absorption of the toxin (enterotoxaemia)

• inhibition of protein synthesis, cell death

• damage of small arteries (microangiopathy),

• permeability increased

• oedema

• irreversible

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Clinical signs

• oedema

• sub cutaneously

• nose,

• ear

• eye

• ataxia

• flaccid paralysis

• dyspnoe

• sudden death

• no fever

• no diarrhoea

• 100% die51 52

Post mortem lesions

• stomach filled

• oedema (stomach, mesentherium, gut, lungs, brain)

Oedema disease

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Diagnosis

• epidemiology – clinical signs – post mortem lesions

• bacterium isolation

• verotoxin production (PCR, Vero cells)

• serotyping

• differential diagnosis

• Aujeszky disease

• Teschovirus encephalomyelitis

• streptococcosis

• Glässer’s disease

• toxicosis

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Treatment

• diseased:

• not feasible (antibiotics, antihistamines)

• penmates:

• per os antibiotics, laxants

Prevention

• decreased portion, increased fibre content

• gradual change of feed

• antibiotics in feed

• vaccines

• fimbriated but not toxin producing strains

• inactivated toxin (not on the market)

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DISEASES OF SHEEP AND GOATS CAUSED BY E. COLI

• coli septicaemia (watery mouth)

• coli -diarrhoea

• similar to the diseases of cattle caused by E. coli

E. COLI DIARRHOEA OF RABBITS

Occurrence

• worldwide

Aetiology

• enteropathogenic E. coli (EPEC)

• (there are no E. coli strains in the gut flora of rabbits)

Epidemiology

• mainly large farms

• insufficient fibre content can predispose

• after weaning (5-12 weeks old)

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Pathogenesis

• decreased fibre content

• decreased volatil acid concentration

• elevated pH

• E. coli can replicate in the gut

• adhesion to the distal small intestine and the larg e intestine

• damage of the microvilli

• decreased absorption

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Clinical signs

• diarrhoea (mucous, watery)

• anorexia

• death

Post mortem lesions

• stomach filled

• enteritis (foamy)

• oedema in the gut wall

• haemorrhages in the gut

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Diagnosis

• epidemiology – clinical signs – post mortem lesions

• isolation of E. coli (gut, mesentherial lymph nodes)

• differential diagnosis

• coccidiosis

• rotavirus

Treatment

• per os antibiotics (colistin, enrofloxacin)

• coccidiostatics

Prevention

• high fibre, low protein content of feed

• gradual change of the food

• no vaccine on the market (only trial)60

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DISEASES OF DOGS AND CATS CAUSED BY E. COLI

• sporadic

• enteritis:

• suckling and young animals, ST producing E. coli

• cat: haemorrhagic enteritis (VTEC)

• urogenital infections

• treatment:

• antibiotics

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DISEASES OF HORSES CAUSED BY E. COLI

• sporadic

• enteral disease

• septicaemia (rare)

• hygiene

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DISEASES OF POULTRY CAUSED BY E. COLI

Occurrence

• worldwide

Aetiology

• invasive E. coli strains

• virulence factors

• F11 fimbia, surface proteins etc.

• certain K-antigens

• cytotoxins (less frequent)

• virulence variants

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Epidemiology

• infection

• horizontal: faeces, indirect infection, wounds

• vertical: eggs (germinative)

• predisposing factors

• management problems, overcrowding

• nutritional deficiencies

• new, high performance hybrids

• other infections: mycoplasma, viruses

• disease is influenced by

• virulence of the agent

• age,

• way of infection

• predisposing factors 64

Pathogenesis

• infection

• embryonic infection (germinative, eggshell)

• death or weak chicken with omphalitis will be hatch ed

• inhalation (hatchery)

• replication in the respiratory ways, local lesions (airsacculitis)

• percutaneous: cellulitis

• per os

• replication in the gut

• septicaemia

• endotoxin effect, damage of the endothelial cells

• parenchymal organs, serous membranes inflammation

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Pathogenesis

• septicaemia

• young

• endotoxin effect, death

• grower, adult

• pericarditis, perihepatitis, airsacculitis, arthrit is

• hen

• coli-granulomatosis:

• liver, gut: inflammatory granuloma around E. coli

• death

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Clinical signs

• day-old chicken (septicaemia)

• omphalitis

• delayed absorption of the yolk sack

• anorexia

• diarrhoea

• die

• growers, adults

• septicaemia

• depression, anorexia, listlessness

• local lesions

• dyspnoe, respiratory signs

• arthritis

• cellulitis 67

Post mortem lesions

• day-old chicken

• omphalitis

• enteritis, haemorrhages

• fibrinous pericarditis

• growers, adults

• septicaemia (haemorrhages, enlarged parenchymal org ans)

• chronic form

• airsacculitis

• peritonitis

• fibrinous pericarditis, perihepatitis

• salpingitis

• granulomas: skin, ovarium, gut68

E. coli infection in poultry

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E. coli infection in adults(septicaemia, salpingitis,

granulomatosis)

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E. coli infection in adults(air sacculitis, cellulitis)

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Diagnosis

• epidemiology – clinical signs – post mortem lesions

• bacteriological examination (isolation from bone ma rrow)

• identification of the primary agent

• differential diagnosis

• salmonellosis

• mycoplasmosis

• infectious bursitis

• infectious anaemia

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Treatment

• antibiotics in water

• treatment of the primary problem

Prevention

• prevention of early mass infection

• rules of egg collection and hatching are kept

• hygiene, disinfection

• all in all out

• probiotics, prebiotics

• vaccines

• inactivated vaccines

• poor heterologous protection

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Public health aspects

• generally not zoonosis except VTEC/EHEC

• babies:

• coli diarrhoea,

• septicaemia

• adults:

• travellers’ diarrhoea

• urinary tract infections

• haemorrhagic enterocolitis

• haemolytic uraemic syndrome

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Public health aspects

Aetiology

• VTEC/EHEC

• CNF producing strains

Epidemiology

• cattle are frequently asymptomatic carriers

• milk, meat, contact, faeces

• dung, food irrigated with sewage water

• small amount of bacteria is enough

• all age groups especially children and elderly are susceptible

• lethality: children (5-10%) and elderly (5-50%)

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Pathogenesis

• damage of endothelial cells

• haemolytic-uraemic syndrome

Clinical signs

• abdominal pain, haemorrhagic diarrhoea

• haemorrhagic faeces

• damaged kidney function

Treatment :

• electrolyte,

• symptomatic treatment

Prevention :

• hygiene

• do not consume row milk, meat76