Transcript Slide 1

Stakeholders Meeting
Park Hyatt Melbourne
November 17 2014
Established and supported
under the Australian
Government’s Cooperative
Research Centres’ Program
2A-107 Antibiotic sensitivity of
H parasuis, APP & other respiratory pathogens
• Why?
– Antibiotic resistance in respiratory pathogens major problem
– Need knowledge of resistance to provide feedback to vets for
TTT
• Highlights/Outcomes
– The MIC and DD methods for H. parasuis are fully validated
for antibiotics commonly used
– The antimicrobial resistance patterns of current isolates of
respiratory pathogens in our pig herd been completed.
– AM-resistance of bacteria isolates varies greatly
– within a pig, across & between batches
• Sampling implications
• Management implications
– There is evidence of a low level of multi-drug resistance and
of resistance to the more recently available agents
2A-108 Evaluation of oral fluid samples for
herd health monitoring of pathogens & the
immune response in pigs
• Why?
– Testing of oral fluids (OFs) may be a useful approach
for herd health monitoring
• Highlights/Outcomes
– Will be able to compare sera and OF for PCV2
– Wasn’t possible to develop an assay to detect
Lawsonia antibodies in OF but results from OF qPCR &
serum ELISA correlated well
– OF testing should be a cost-effective means of herd
health monitoring; it has the potential to detect a
wide range of viral and bacterial pathogens and
associated antibody responses.
– Developed strong association with Jeff Zimmerman's
lab at the University of Iowa.
2A-109 Development and validation of
assays to measure gut health in order to
identify risk factors for E.coli disease in
weaner pigs
• Why?
– Gut health can be measured by quantifying the ratio of
beneficial and pathogenic bacteria
• Highlights/Outcomes
– Ratios of commensal to pathogenic bacteria completed
– Sample collection finished – correlation of ratios with
diarrhoea scores
– Ratios agreed with Nutreco’s work in the Netherlands
– Lacto:C.perf or to E.coli were much higher in the healthy
pigs
– Good correlatation of bacterial ratios (culture techniques)
with qPCR techniques
– Identification of other commensal bacteria that may play a
more important role in influencing gut health and disease
suppression.
2B-103 & 2B-104: Susanne Hermesch
• Research collaborations
– Australia:
CSIRO, NSW DPI, PIC Australia, Rivalea, UQ – Gatton
– International:
Hélène Gilbert, INRA, France (left)
Andrea Doeschl-Wilson, Roslin Institute, Scotland
• Practical selection strategies for robustness
• Consequences of selection for efficiency on
aspects of robustness
• Defining disease resilience
Practical selection strategies for robustness
• Environmental variation observed on farms
requires different genotypes
– Growth rate is genetically a different trait when
environments differ by more than 60 g/day
genetic correlations
1
Proposed selection strategy
applies simpler multi-trait
approach to continuous
environmental descriptor
0.9
R² = 0.77
0.8
0.7
0.6
0.5
0
20
40
60
80
100
120
140
Difference between environments (means; g/day)
Graph from Hermesch and Li (2013)
New
Consequences of selection for efficiency
on aspects of robustness
• Contrary to expectations, the more efficient
line (LRFI) was less sensitive to variation in
environments for growth
g/d 900
870
HRFI
840
810
LRFI
780
750
More efficient pigs may be
able to derive nutrient
resources more effectively
when needed to face
stressors.
720
690
660
630
-55 -45 -35 -25 -15 -5
Unfavourable
5
Environment
15
25
35
45 55
LsCG , g/d
Favourable
Is the resource allocation
theory too linear?
New
Graph from Gilbert et al. (2014)
Defining disease resilience
• Genes of the sow should be considered
more in selection decisions (Hermesch et al., 2014)
• Workshop and book on resilience
– Susanne Hermesch: Breeding disease resilient
pigs
– Alison Collins: On-farm measures to monitor
health and immune status of pigs
– Andrea Doeschl-Wilson: Inferring genetic
resilience of animals to infectious pathogens –
opportunities and pitfalls
2A 102: Marc Marenda
University of Melbourne
• Objective: Proof of concept of:
– Real time measurement of bacterial concentration in
selected sites within piggery
– Total bacteria counts: Using culture
– Selected pathogen counts, EC & APP: Using qPCR
• Entailed selection of suitable air sampler for field use
• Further development needed (not necessarily with
CRC support)
– Widen range of pathogens to include M hyo, H parasuis,
Strep suis
– Cheaper sampler (Project sampler $10k)
– Validate accuracy & consistency on a larger range of farms
2C 102: Alison Collins
EMAI
• Objective: to develop quantitative
Lawsonia PCR for field use
• Observational studies on 4 farms with
ileitis
– Confirm that the variability of LI load is
limited in the absence of management
changes
• `Observed changes in LI load in response to
medication changes
– ADG regression, 10-15 weeks of age
• 106 to 107 LI/g: Loss of 15 g/d
• 107 to 108 LI/g: Loss of 140 g/d, ie 2.9 kg over
a 21 day period
2C 102: Alison Collins
EMAI
• Experimental study (D0: 9 wks)
Enterisol + lime
D49
5.7
Control
6.3
LI, log 10/g faeces
D56
D70
8.9
8.6
8.9
In feed
Olaquindox 50 ppm
2.5
3.3
8.2
D84
7.3
ADG, kg
D 0-90
0.871
6.4
0.845
Withdrawn
5.7
10.6
Major
outbreak
0.831
2C 110: Jae Kim, DAGF WA
2C 112: Joshua Sweeny, DAGF WA
• Objectives: Confirmation that weaner health &
growth can be improved by suppressing the
immune response to E coli infection
• 2C 110
• Production trial, FCR
•
•
•
•
•
Control
Aspirin, 125 ppm
Vitamin E, 250 IU/kg
Aspirin + Vit E 1.55
1.66
1.58
1.55
Diarrhea index
• Control
• Aspirin + Vit E
6.7
4.2
2C 110: Jae Kim, DAGF WA
2C 112: Joshua Sweeny, DAGF WA
– 2C 112: N acetylcysteine (NAC)
• Production trial, ADG in gms/D
– Control
– NAC 0.5 g/kg + arginine 8 g/kg
180
239
– Other parameters
• Faecal HEC score 2.9 vs 2.0
• Villus height, um 385 vs 463
• Regulatory issues with APVMA, State DPIs
– Aspirin, N acetylcysteine
2C 105: Eugeni Roura
• Objectives
UQ
– Feeding weaners PEEOs (plant extracts & essential
oils) which are antibacterial and optimise feed
intake, so reducing PWD incidence
• Entails conditioning of weaners through feeding PEEOs
during pregnancy and lactation
• Stages
– Phase 1: Screen candidate PEEOs in vitro for
antibacterial activity
– Phase 2: Screen candidate PEEOs for capacity to
diffuse into amniotic fluid, milk (and saliva)
• Methodology to be developed
– Maximise gut uptake of PEEOs by developing
emulsion technology
– Phase 3: Weaner trials, preferably in association
with commercial partner
2C 105: Eugeni Roura
UQ
• Results
– Phase 1: antibacterial action in vitro
• Best: oregano, cinnamon, clove and thyme
• Best native: lemon myrtle, lemon ironbark, nerolina and
peppermint eucalyptus
– Phase 2
• Methodology achieved
– Emulsion technology
• Progress
– Phase 3:
• One weaner trial completed
– Problems with weaner feed intake: level of PEEO inclusion needs
finetuning
• Looking for commercial partner to help conduct weaner
trials
2C106, 2C 113: Sharon Bishop-Hurley
CSIRO
• Objective: Use phage display library to identify
novel peptides antibacterial to E coli
• Progress
– Selection of 3 phage display peptides which between
them:
• Bind to a range of 50 Australian E coli pathotypes
• Are antibacterial against the range of pathotypes
– Choice between pursuing administration of peptides
attached to their phage coat, or further synthesis of
peptides using recombinant technology, for
administration without the phage coat
– Latter course to be pursued
• Fewer biosecurity/APVMA issues
• Synthetic peptides found to be more active, at this point
2C106, 2C 113: Sharon Bishop-Hurley
CSIRO
• Incidental commercialisation opportunities?
– Binding of peptides to EC is highly specific: indicates
potential to develop on farm diagnostic tool for faeces
from infected weaners
–
One of candidate peptides self assembles into an
amphiphilic antibacterial gel
• Next steps, early 2015
– Selection of most active and specific synthetic peptides
(3)
– Incorporation into digestion resistant nanoparticle
– Evaluation in CSIRO in-vitro fermentation model
Future Directions
• APP & respiratory disease
– 2C 115: Causes of pleurisy (by June 2015)
– 2C 116: Attenuated live APP vaccine
strains (by March 2016)
– 2C 118: Airspace sanitation for APP
control (by December 2016)
• E coli
– 2C 114: Manipulation of fibre levels in
weaner diets to control E coli infection
and
simultaneously
use
statistical
sequencing to better understand what
constitutes a healthy gut flora in the
weaned pig (by June 2015)
Future Directions
• Prediction of disease onset
• Selection for Robustness
– Molecular techniques