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Diagnostic approach for E. coli infections in pigs and control of post-weaning diarrhœa with a live oral vaccine
By John Morris Fairbrother Professor [email protected]
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E. coli bacterium showing virulence factors and surface antigens used for bacterial classification by virotype and serotype
Escherichia coli
Flagella (H)
Production of toxins
Capsule (K)
LPS (O)
Fimbriae (F)
Cell membrane
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E. coli population Sub-sets of clones differentiated by their ability to cause disease
Clone
Clone with resistance gene
Pathogenic
Potentially pathogenic
Commensal
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Virulence factors of pathogenic E. coli in pigs
STEC
EPEC
ETEC
ExPEC
Eae
Aero CNF
P Tsh
LT STa STb
Stx1 Stx2
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ETEC: How they cause disease in pigs
E. coli with fimbriae
Receptor
Epithelial cell
Toxin
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2 Colonisation
of the jejunum and ileum
3 Water Electrolytes
4 Diarrhœa
Weight loss Death Ingestion
of ETEC
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ETEC diarrhœa
Newborn piglet with clinical signs of E. coli diarrhœa
Fluid distension and congestion of the small intestine of an unweaned piglet
with E. coli diarrhœa
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Intestinal colonisation by ETEC
Layers of E. coli bacteria (arrows) adhering to the mucosa of the ileum in a piglet with ETEC diarrhœa
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STEC: How they cause disease in pigs
E. coli with fimbriae
Epithelial cell
Blood vessel
Toxin
Receptor
2 Colonisation
of the jejunum and ileum 3
Transport of toxin to circulation
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Œdema Ataxia Death
1 Ingestion of STEC
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Œdema disease
Degenerative angiopathy of a small artery with swelling of endothelial cells (arrow), œdema, and haemorrhage in the ileum of a weaned pig with œdema disease
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EPEC: How they cause disease in pigs
Receptor
Eae adhesin
Adherent E. coli
Epithelial cell
1 Ingestion of EPEC
2 Colonisation of small and large
intestine
3
4
Intimate attachment of epithelial cells + effacement of
microvilli
Diarrhœa
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Extensive multifocal bacterial colonisation of the surface epithelium by a thin layer of dark-stained
coccobacilli oriented in a palisade pattern (arrows), in the colon of a weaned pig with diarrhœa
Intestinal colonisation by EPEC
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Aetiology Risk factors E. coli
pathotype Host Environment
Œdema disease STEC:F18
-Some pigs resistant to F18 due to lack of receptor
-Up to 50% pigs may be resistant to F4 due to lack of receptor
-Earlier weaning age
-Stress
- Loss of specific antibodies from milk
Rapidly growing pigs
- High protein diet - Transportation - Mixing of pigs
Post-weaning
diarrhœa
ETEC:F4, F18, ETEC:AIDA, EPEC, mixed E. coli pathotypes
-Diet changes
- Diet constituants - Low level of milk and other products of animal source
- Certain ingredients such as soy beans
- Presence of other infections, such as PRRSv or pseudorabies virus
Risk factors for development of Escherichia coli disease
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Direct smear from the colon of a healthy post weaning pig -
heterogeneous Gram-positive and gram-negative population
Postweaning pig with E. coli diarrhœa - predominance of
Gram-negative rods
Intestinal microflora
drastically altered in pigs with diarrhœa
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Elimination of commensals and predominance of pathogenic E. coli
Healthy pig Pig with E. coli diarrhoea
Intestinal mucosa in disease
E. coli commensal clones
E. coli pathogenic clones E. coli potentially pathogenic clones
Other bacterial species
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Transformation of the E. coli profile
in the pig intestinal ecosystem on the onset of disease
1 2 3 4 5 6 7 9 8
Viru
lenc
e
1 2 3 4 5 6 7 9 8
Viru
lenc
e
Bacterial count (log)
Pig with sub-clinical infection Pig with E. coli diarrhoea
Commensal clones
Pathogenic clones Potentially pathogenic clones
Detection limit of diagnostic test
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on causative agents (Kirby Bauer)
Positive Negative 3 or more selected haemolytic
and/or lactose +ve colonies
Blood and/or selective (McConkey) Agar
Virotyping Multiplex PCR
Enrichment (overnight)
Multiplex PCR
Rapid evaluation of presence of E. coli pathotypes
Sample analysis Isolate analysis
Detection and identification of pathogenic E. coli Clinical sample
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Clinical diagnosis
Added virulence factors tested in isolates from animals
ExPEC
ETEC
STEC
EPEC
Aero CNF
P Tsh
LT STa STb
Stx1 Stx2
Eae
F4 F5 F6
F41
F18
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Cases (%)
associated with post-weaning diarrhœa in pigs according to age in Canada from 2008 to 2010
E. coli pathotypes
www.apzec.ca
22 Antimicrobial resistance
on causative agents (Kirby Bauer)
Positive Negative 3 or more selected haemolytic
and/or lactose +ve colonies
Blood and/or selective (McConkey) Agar
Virotyping, Multiplex PCR, and colony hybridisation
Enrichment (overnight)
Multiplex PCR
Rapid evaluation of presence of E. coli pathotypes
Sample analysis Isolate analysis
Detection and identification of pathogenic E. coli Clinical sample
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Surveillance Added virulence factors tested by colony hybridisation in animals
Stx1 Stx2
F18
Eae
Tsh
Aero
LT STa STb
F4 F5 F6
F41
AIDA Paa
F17
CNF P
Afa
ExPEC
ETEC
STEC
EPEC
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Prevalence of main E. coli pathotypes
Feedlot Nursery
Sow barns
% of cases
in pigs according to age in Canada from 2008 to 2010
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Prevalence of E. coli pathotypes
Number (%) of positive cases in pigs of age: All 1-14 days 15-35 days
Colibacillosis – Causative agent
ETEC:F4 28 (30.1) 6 (15.8) 18 (56.3) ETEC:F5 8 (8.6) 4 (10.5) 3 (9.4) ETEC:F6 1 (1.1) 0 0
ETEC:F18 0 0 0 ETEC:F41 1 (1.1) 1 (2.6) 0 STEC:F18 1 (1.1) 0 1 (3.1)
Colibacillosis – Opportunistic agent
EPEC 10 (10.8) 1 (2.6) 5 (15.6) ETEC:AIDA 12 (12.9) 3 (7.9) 4 (12.5)
Colibacillosis – Possible agent
ETEC, others 8 (8.6) 1 (2.6) 3 (9.4) Negative 34 (36.6) 23 (60.5) 5 (15.6)
Total 93 38 32
in pig intestines or faeces of cases of diarrhœa at EcL in 2007
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Number (%) of positive cases in pigs of age: All 1-14 days 15-35 days
Colibacillosis – Causative agent
ETEC:F4 28 (30.1) 6 (15.8) 18 (56.3) ETEC:F5 8 (8.6) 4 (10.5) 3 (9.4) ETEC:F6 1 (1.1) 0 0
ETEC:F18 0 0 0 ETEC:F41 1 (1.1) 1 (2.6) 0 STEC:F18 1 (1.1) 0 1 (3.1)
Colibacillosis – Opportunistic agent
EPEC 10 (10.8) 1 (2.6) 5 (15.6) ETEC:AIDA 12 (12.9) 3 (7.9) 4 (12.5)
Colibacillosis – Possible agent
ETEC, others 8 (8.6) 1 (2.6) 3 (9.4) Negative 34 (36.6) 23 (60.5) 5 (15.6)
Total 93 38 32
Prevalence of E. coli pathotypes in pig intestines or faeces of cases of diarrhœa at EcL in 2007
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Number (%) of positive cases in pigs of age: All 1-14 days 15-35 days
Colibacillosis – Causative agent
ETEC:F4 28 (30.1) 6 (15.8) 18 (56.3) ETEC:F5 8 (8.6) 4 (10.5) 3 (9.4) ETEC:F6 1 (1.1) 0 0
ETEC:F18 0 0 0 ETEC:F41 1 (1.1) 1 (2.6) 0 STEC:F18 1 (1.1) 0 1 (3.1)
Colibacillosis – Opportunistic agent
EPEC 10 (10.8) 1 (2.6) 5 (15.6) ETEC:AIDA 12 (12.9) 3 (7.9) 4 (12.5)
Colibacillosis – Possible agent
ETEC, others 8 (8.6) 1 (2.6) 3 (9.4) Negative 34 (36.6) 23 (60.5) 5 (15.6)
Total 93 38 32
Prevalence of E. coli pathotypes in pig intestines or faeces of cases of diarrhœa at EcL in 2007
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Number (%) of positive cases in pigs of age: All 1-14 days 15-35 days
Colibacillosis – Causative agent
ETEC:F4 28 (30.1) 6 (15.8) 18 (56.3) ETEC:F5 8 (8.6) 4 (10.5) 3 (9.4) ETEC:F6 1 (1.1) 0 0
ETEC:F18 0 0 0 ETEC:F41 1 (1.1) 1 (2.6) 0 STEC:F18 1 (1.1) 0 1 (3.1)
Colibacillosis – Opportunistic agent
EPEC 10 (10.8) 1 (2.6) 5 (15.6) ETEC:AIDA 12 (12.9) 3 (7.9) 4 (12.5)
Colibacillosis – Possible agent
ETEC, others 8 (8.6) 1 (2.6) 3 (9.4) Negative 34 (36.6) 23 (60.5) 5 (15.6)
Total 93 38 32
Prevalence of E. coli pathotypes in pig intestines or faeces of cases of diarrhœa at EcL in 2007
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Correlation of E. coli pathotypes
Number of cases
Examined by necropsy
With histopathological evidence of: Bacterial colonisation Submucosal
œdema stomach
Pathotype combination Intestine Colon
ETEC:F4 10 9 ETEC:F4 mixed 9 6 1
ETEC:F4+STEC:F18 1 1 ETEC:F5 5 2
ETEC:F6+EPEC 1 1 ETEC:F18 1 1 STEC:F18 4 2 4
STEC:F18+EPEC 1 1 EPEC 13 4 1
ETEC:AIDA 14 4 1 EPEC+ETEC:AIDA 2 2
ETEC, others 11 1 Negative 67 3 3
and histopathological findings for submitted pigs in 2007
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Number of cases
Examined by necropsy
With histopathological evidence of: Bacterial colonisation Submucosal
œdema stomach
Pathotype combination Intestine Colon
ETEC:F4 10 9 ETEC:F4 mixed 9 6 1
ETEC:F4+STEC:F18 1 1 ETEC:F5 5 2
ETEC:F6+EPEC 1 1 ETEC:F18 1 1 STEC:F18 4 2 4
STEC:F18+EPEC 1 1 EPEC 13 4 1
ETEC:AIDA 14 4 1 EPEC+ETEC:AIDA 2 2
ETEC, others 11 1 Negative 67 3 3
Correlation of E. coli pathotypes and histopathological findings for submitted pigs in 2007
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Number of cases
Examined by necropsy
With histopathological evidence of: Bacterial colonisation Submucosal
œdema stomach
Pathotype combination Intestine Colon
ETEC:F4 10 9 ETEC:F4 mixed 9 6 1
ETEC:F4+STEC:F18 1 1 ETEC:F5 5 2
ETEC:F6+EPEC 1 1 ETEC:F18 1 1 STEC:F18 4 2 4
STEC:F18+EPEC 1 1 EPEC 13 4 1
ETEC:AIDA 14 4 1 EPEC+ETEC:AIDA 2 2
ETEC, others 11 1 Negative 67 3 3
Correlation of E. coli pathotypes and histopathological findings for submitted pigs in 2007
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Sample
Enrichment
Multiplex PCR APZEC pathotype • Virulence genes
Positive isolates colonies • Virotype • O serotype
• Antimicrobial resistance
APZEC strain collection
APZEC database
Data presentation • Geographical location • Age
• Disease • Animal species • Time
APZEC Approach
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E. coli profile
Virulence genes
Antimicrobial resistance and
genes
O type, phylogenetic
type, pulse type
Demographic data
Animal species
Time of collection
Animal age
Geographical location
Diagnosis
Clinical signs
Histopatho-logical lesions
Global APZEC Project
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Trends in resistance to antimicrobials in pathogenic E. coli from diseased pigs in Canada with time from 2008 to 2010
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Trends in resistance to antimicrobials in pathogenic E. coli from diseased pigs in Canada with time from 2008 to 2010
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Resistance to antimicrobials in pathogenic E. coli in intestinal samples from diseased pigs in Quebec from 2008 to 2010 in relation to age
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Sampling kit Shipped to you with detailed protocol
Sampling at the farm
Canadian F4-ETEC Diagnostic Survey Join national survey to evaluate the presence of F4-enterotoxigenic E. coli on Canadian swine farms Criteria: Farms with enteric cases (soft faeces, scours, anorexia, etc.), with sudden death, or facing suboptimal growth performance in the first 3 weeks post-weaning. Please refer to the protocol for more information.
Shipping box
Swabs
Ice pack FedEx waybill
Cooler
Rectal swabbing
Swab in the tube
Tube identification
Swabs stored on ice or refrigerated
2
1
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Shipping of samples
Results Communicated confidentially to veterinarians via email within 7 days of sample reception
Detection of F4-ETEC at the EcL Laboratory
+
Confirmation of F4-ETEC by PCR Enrichment of swab Isolation of E. coli
Pre-paid shipment
3
4
5
Canadian F4-ETEC Diagnostic Survey
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Strategies which result in: Reduced number of pathogenic E. coli
Increased resistance of animals to infection
- Increase weaning age - Warmth - Diet - Highly digestible - Milk-based protein - Restricted feed intake - Hygiene - Water additive - Organic acids - Feed supplements - Organic acids - ZnO - Spray-dried plasma - Probiotics
- Live oral non-toxigenic F4 and F18 E. coli vaccines
- Oral powdered egg yolk from F4 and
F18 immunised hens - Stx toxoid vaccine (œdema disease) - Selection of F4 and F18-resistant
animals
of enteric E. coli infections in post-weaning diarrhœa and œdema disease
Strategies for control
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Strategy should specifically target pathogenic E. coli Maintain beneficial E. coli Minimal effect on protective normal intestinal flora
Safe Positive effect on animal health would be an added
value Environmentally friendly Economical Practical
Desirable properties of intervention strategies
to control E. coli post-weaning diarrhœa in pigs
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Desirable outcome of control strategy E. coli colonise and persist in a complex intestinal ecosystem in healthy animals
Pathogenic E. coli Commensal E. coli Other bacterial commensals
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Undesirable outcome of control strategy Pathogenic E. coli may build up and colonise the intestinal mucosa
Pathogenic E. coli Commensal E. coli Other bacterial commensals
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Growth promoting in feed or oral therapy Not specific for pathogenic E. coli Development of antimicrobial resistance Upset of intestinal microflora and possible
overgrowth and increased faecal shedding of ETEC or STEC
Induce emergence of new pathogenic and possible zoonotic E. coli such as O104:H4
Antimicrobials
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Effect on the intestinal ecosystem
After Before
Worst case scenario
Antimicrobials
Pathogenic E. coli Commensal E. coli Other bacterial commensals
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Experimental design & sampling 80 pooled faecal samples (rectal and floor) were collected from pigs receiving a diet with or without 2% Clinoptilolite
Days after weaning
0 2 7 14 28 168 piglets in 6 pens
CTC PG CTC & PG 0 7 14 28
Antimicrobials used as growth promoter in diet:
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Antimicrobial resistance profiles in E. coli isolates from pigs receiving or not clinoptilolite in the feed as detected by disk diffusion method (* P< 0.05)
Time Group Total No. of
isolates
No. of isolates by No. of antimicrobial classes in the
resistance pattern
No. of resistant Isolates by antimicrobial class and antimicrobial(%)
Aminoglycosides β-lactams Sulfonamides Phenicols Quinolones Tetracyclines
0 1-2 3-4 5-6 GEN KAN STR AMP AMC CRO FOX TIO FIS SXT CHL CIP NAL TET
Day 0 C- 10 1 4 5 0 3 4 5 5 2 0 0 0 6 6 0 0 1 8 C+ 10 2 3 4 1 0 1 4 4 1 0 0 0 6 6 2 0 0 6
Day 7 C- 10 0 1 5 4 2 4 9 9 7 0 0 0 9 8 4 1 1 10 C+ 10 0 0 4 6 2 2 10 10 9 4 4 4 10 10 6 0 1 10
Day 14 C- 10 0 0 7 3 3 0 8 10 7 0 0 0 7 7 6 0 0 10 C+ 10 0 0 5 5 3 3 10 10 10 3 3 3 10 9 4 0 1 10
Day 28 C- 10 0 1 5 4 1 1 7 9 8 5 5 5 7 7 6 0 0 10 C+ 10 0 2 5 3 1 3 9 10 8 4 4 4 9 9 4 0 0 10
Total 80 3(3.75) 11(13.75) 40(50) 26(32.5) 15(18.75) 18(22.5) 62(77.5) 67(83.7) 52(65) 16(20) 16(20) 16(20) 64(80) 62(77.5) 32(40) 1(1.25) 4(5) 74(92.5)
All isolates were susceptible for AMK All ceftiofur-cefoxitin-resistant E.coli isolates were co-resistant to AMC,
AMP, STR, SXT, FIS, CHL and TET
AMC: Amoxicillin/Clavulanic acid AMK: Amikacin AMP: Ampicillin CHL: Chloramphenicol CIP: Ciprofloxacin
C-: Control group C+: Treatment group
CRO: Ceftriaxone FIS: Sulfisoxazole FOX: Cefoxitin GEN: Gentamicin KAN: Kanamycin
NAL: Nalidixic acid STR: Streptomycin SXT: Trimethoprim-Sulphamethaoxazole TET: Tetracycline TIO:Ceftiofur
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Trends in presence of blaCMY-2 gene in fecal samples from weaned pigs over time, as detected by PCR (* P< 0.05)
0
20
40
60
80
100
0 2 7 14 28
% o
f pos
itive
sam
ples
Days
Control Treatment
*
*
*
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0,0
2,0
4,0
6,0
8,0
10,0
12,0
14,0
16,0
18,0
0 2 7 14 28
% o
f pos
itive
isol
ates
Days
blaCMY-2
Control
Treatment
* *
*
Trends in isolates positive for iucD, tsh or blaCMY_2 genes in fecal samples from pigs as detected by HGMF method (* P<0.05)
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0 0 0
2
0 0 0
3
0
4
3 3
0
1
0
1
2
3
4
5
6
C- C+ C- C+ C- C+ C- C+
Day 0 Day 7 Day 14 Day 28
No.
of b
laC
MY-
2 po
sitiv
e is
olat
es
phylotype B1
phylotype A
40%
60%
75%
25%
100%
100%
Association between blaCMY-2-positive isolates and Phylogenetic grouping over time
C-: Control group C+: Treatment group
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Certain strains of Enterococcus faecalis , Lactobacillus spp
Daily oral treatment starting before susceptible period Gradual onset of effect
Stimulate beneficial microorganisms Competitive exclusion Non-specific
Many products on the market Increased weight gain Variable efficacy
Probiotics
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Effect on the intestinal ecosystem
After Before
Probiotics
Pathogenic E. coli Commensal E. coli Other bacterial commensals
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Feed supplementation with egg yolk antibodies from immunised chickens specific for F4 and F18
Specific inhibition of intestinal colonisation of ETEC
No effect on normal intestinal microflora
Rapid onset of action, lasts as long as in feed
Controlled efficacity studies show promise
Passive immunotherapy
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Administration in the feed of powdered egg yolk from hens immunised with F4 or F18 results in blocking of bacterial adherence to epithelial cells of the intestinal mucosa due to the presence of specific anti-F4 or F18 antibodies
Passive immunisation of young pigs
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with an injectable killed whole-cell bacterin or purified fimbrial subunit vaccine leads to protection of young pigs from ETEC infection
Maternal immunisation
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After Before
Passive immunotherapy Effect on the intestinal ecosystem
Pathogenic E. coli Commensal E. coli Other bacterial commensals
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Breed to increase prevalence of F4 and F18 resistance loci
Possible co-selection of unwanted traits due to linkage of resistance locus with these traits
Susceptibility is genetically dominant Resistant sows do not produce or transfer F4-
specific antibodies to colostrum or milk Additional F4 resistance loci need to be
identified Availability of techniques for large-scale
selection of resistant animals is lacking
Breeding for resistance
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E. coli with fimbriae
Receptor
Toxin
Selection of F4 and F18 resistant animals
After Before
Epithelial cell
Epithelial cell
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Oral vaccination
Specific mucosal
immunity: Anti-F4 antibodies
Specific antibodies block
bacterial adherence
Vaccines
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Immunisation results in production of antibodies Specific inhibition of intestinal colonisation of
ETEC F4 Live non-toxigenic F4-positive E. coli strain
No effect on normal intestinal microflora
One or more doses, gradual onset of effect, more long-lasting
Decreased faecal shedding in controlled and field studies
Vaccines
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Effect on the intestinal ecosystem
Vaccines
After Before
Pathogenic E. coli Commensal E. coli Other bacterial commensals
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Specific Safe Positive effect on animal health Environmentally friendly Economical Practical
Strategies for control Summary of features
-
- -
- - -
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Oral live vaccine
Containing naturally avirulent culture of E. coli: Positive for F4 Negative for toxins and other virulent factors
Recommended for the vaccination of weaned pigs as an aid in the prevention of post-weaning diarrhœa (PWD) caused by F4-positive ETEC
Lyophilized multi-doses formats: 200 doses 500 doses
The Coliprotec™ vaccine
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Experimental design
Weaning (17-day old pigs)
Coliprotec/Placebo
Challenge (F4+ETEC)
0 1 2 3
4 5
6
7 8
9 (DPC 1)
10 (DPC 2)
11 (DPC 3)
Day
pos
t-wea
ning
Necropsy (peak of clinical signs)
- Confirmation of the absence of F4-ETEC strain from the source of pigs
- Individual weight (growth and DWG) - Excretion of F4+ETEC (CFU/g of faeces)
- Diarrhœa scoring (0=normal to 4=watery)
Controlled challenge studies
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- Colonisation of F4+ETEC in the intestines (CFU/g of tissue)
- Scoring for accumulation of fluid in the intestines (0=normal to 3=mainly liquid)
Weaning (17-day old pigs)
Coliprotec™/Placebo
Challenge (F4+ETEC)
0 1 2 3
4 5
6
7 8
9 (DPC 1)
10 (DPC 2)
11 (DPC 3)
Day
pos
t-wea
ning
Necropsy (peak of clinical signs)
Experimental design
Controlled challenge studies
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Proportion of pigs excreting >1 x 108 CFU/g of faeces or being colonised by >1 x107 CFU/g of jejunum
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Challenge DPC 1 DPC 2 DPC 3 Necropsy (DPC3)
Fecal excretion of F4-ETEC Colonisation of jejunum by F4-ETEC
Prop
ortio
n of
pig
s
High infectious pressure
Coliprotec™ reduced F4+ETEC colonisation and excretion
Coliprotec™
Placebo
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0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Challenge DPC 1 DPC 2 DPC 3 Jejunum Ileum Caecum Colon Rectum
High infectious pressure
Severe diarrhoea Accumulation of fluid
Coliprotec™ reduced fluid in the intestines and diarrhœa
Proportion of pigs with severe diarrhœa (score >2) and fluid in the intestines (score >1)
Prop
ortio
n of
pig
s
Coliprotec™
Placebo
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0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Diarrhea Fluid accumulation Diarrhea Fluid accumulation
High infectious pressure Low infectious pressure
Proportion of pigs with diarrhœa (cumulative score >4) and fluid in the intestines (cumulative score >7)
Prop
ortio
n of
pig
s
Coliprotec™
Placebo
Coliprotec™ reduced fluid in the intestines and diarrhœa
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Susceptibles Tous Susceptibles Résistants
Pression forte Pression faible
37
308
200
395 393 410
370
421
High infectious pressure Low infectious pressure
All pigs Susceptible Resistant
Coliprotec™ improved DWG after F4+ETEC infection
Daily weigh gain (g) during the post-challenge period
Coliprotec™
Placebo
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Overall production performance and mortality during the nursery phase
Room Weaning groups
Vaccinated with
Coliprotec
# Pigs
Moderate to severe diarrhoea
Total weight gain
per animal*1
Daily weight gain *1
Daily Feed
Intake*1
Feed conversion
Mortality at exit
3 4 and 5 No 200 30% 35.9 Kg 463.6 g 81.7 Kg 2.04 11.0%
4 6 and 7 Yes 219 1.4% 37.9 Kg 489.1 g 101.5 Kg 2.00 4.1%
Improvement +2 Kg +5% +24% -2% -6.9%
*1 Average for the 2 weaning groups of the room
Effect of oral administration of Coliprotec™
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Conclusion statement for Coliprotec™
Coliprotec™ significantly reduced: Intestinal colonisation and excretion of F4-ETEC Accumulation of fluid in the intestines Diarrhœa Weight loss
Coliprotec™ significantly improved weight gain resulting in normal growth rates after F4-ETEC infection compared to the rapid loss of growth observed after the challenge for unvaccinated pigs.