session 2: genome-informed diagnostics - in-field detection of bacterial plant pathogens
TRANSCRIPT
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
In-field Detection of Bacterial Plant PathogensGenome-Informed Diagnostics
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
PBCRC2002 & PBCRC2156• 2002: Develop & validate laboratory and field
diagnostic protocols for plant pathogenic bacteria to the pathovar level of discrimination
• 2156: Deploy validated field diagnostic protocols for plant pathogenic bacteria to the pathovar level of discrimination
• Increase national capability in plant bacteriology
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
PBCRC 2002: Genome-based, bioinformatics-informed diagnostics• Developed & validated multiple laboratory and field
diagnostic protocols for plant pathogenic bacteria to the pathovar level of discrimination
• Validated Pan-Genome Pipeline• Increased national capability in plant bacteriology:
9 scientists trained & mentored in plant bacteriology (Australia, New Zealand, U.S.)
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
Other 2002/2156 Team Presentations – Don’t miss:• Sarah Thompson: Metagenomic discovery of differential
diagnostic loci in CLos • Jacqui Morris: Microflora analyses of the Australian eggplant
psyllid• Rachel Mann: Complex diagnostics – keeping up with Ralstonia
solanacearum• Toni Chapman: Genome-informed diagnostics – Xanthomonas
citri subsp citri• Rebecca Roach: Identification of Xanthomonas species causing
bacterial leaf spot in Australia
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
PBCRC 2156: Field-deployable genome-based, bioinformatics-informed diagnostic protocols• Developed & validated multiple field-deployable
diagnostic protocols for plant pathogenic bacteria to the pathovar level of discrimination
• Validated Concept-to-Practice Pipeline• Engaged end-user communities in field testing and
validation of protocols: laboratory and in-field end-user training in new technologies and protocols
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
PBCRC 2002/2156: Diverse Bacterial targets• Xanthomonas citri subsp. citri: Gram negative, citrus
pathogen• Candidatus Liberibacter solanacearum: Unculturable
bacterium, arthropod vector, potato pathogen• Ralstonia solanacearum: Gram negative, potato
pathogen (other hosts)• Rathayibacter toxicus: Gram positive, nematode
vector, annual ryegrass (other hosts)• Pseudomonas syringae pv. actinidiae: Gram negative
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
Bacterial Pathovar Diagnostics Team:
Xanth Liberibact Pseudo Rathay Erwinia Total
Genomes sequenced
80 10 2 10 102
Target # 80 30 70 39 50 269
New taxasequenced
12 2 2 16
PsylidMitogenomes sequenced
14 (5 species)
14
170 20 4 70 31248
R. sol
200 214
biosecurity built on scienceScience Exchange - August 2016
• Who are you?• Where did you come from?• How did you get here?• When did you get here?• Have you been here before? (prior
entry)• Are you travelling alone? (vector)
Outbreak response:
You can’t answer those questions from symptoms alone
Plant Biosecurity: Smart Surveillance
Pictures: J. Stack lab
How much can we determine in the field?
What do we want to know?
Particularly difficult with bacterial pathogensCan genome-informed diagnostics help?
biosecurity built on science
Plant Biosecurity: Smart Surveillance
Pictures: J. Stack lab
Whoa Dude! Look what I
found.
biosecurity built on scienceScience Exchange - August 2016
Plant Biosecurity: Smart Surveillance
• Who are you: What pathogen is this?• For most bacterial pathogens, the level
of discrimination is at the sub-specific level
• For biosecurity, we need to know the race, strain, or even the population
What do we want to know?
Can be very difficult for bacterial pathogens using traditional technologies –
Almost impossible in the field
biosecurity built on scienceLAMP Workshop – La Trobe University
24 October 2016
Pictures: J. Stack lab
Discriminating peppers from cows
Plant Biosecurity: Smart Surveillance
No characteristics in common No special training required
biosecurity built on scienceLAMP Workshop – La Trobe University
24 October 2016
Pictures: J. Stack lab
Discriminating sheep from cows
Plant Biosecurity: Smart Surveillance
Shape, 4 legs, head, tail, 2 eyes, 2 earsNo special equipment required
biosecurity built on scienceLAMP Workshop – La Trobe University
24 October 2016
Pictures: J. Stack lab
Discriminating cows from cows
Color, weight, height, markings
Many fewer discriminating characteristics
Plant Biosecurity: Smart Surveillance
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Pictures: J. Stack lab
Many distinguishing features
Discriminating bacteria from fungi
Plant Biosecurity: Smart Surveillance
biosecurity built on scienceScience Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Pictures: J. Stack lab
No distinguishing features
Discriminating bacteria from bacteria
Almost impossible in the field
biosecurity built on scienceScience Exchange - August 2016
Pictures: International Symposium on Bacterial Canker of Kiwifruit
Plant Biosecurity: Smart Surveillance
Pseudomonas syringae
Pseudomonas syringae
Kiwifruit Pathogen
Non-Pathogenic
Pictures: International Symposium on Bacterial Canker of Kiwifruit
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
Why rapid is important
Pictures: International Symposium on Bacterial Canker of Kiwifruit
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
highimpact
Impactthreshold
lowimpact
diseasedetection
Critical response point
Time
Dis
ease
sev
erit
y
Pictures: International Symposium on Bacterial Canker of Kiwifruit
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
Localspread
outbreak
EradicationContainment
Containment
Containment – Eradication Window
Increasedspread
Pictures: International Symposium on Bacterial Canker of Kiwifruit
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
Localspread
outbreak
EradicationContainment
Containment
Containment – Eradication WindowContainment to Management
Dis
ease
sev
erit
y
Time
Impact
Critical response point
Early detection
DetectionLimit
SMART SurveillanceBetter diagnostic technology
Diagnostic Methods & Early Detection
What if it is not a sporulating fungus?
pathogen isolation & culture
1 – 2 days for most bacteria
Traditional Diagnostic Methods
10 - 14 days for Rathayibacter
Pictures: International Symposium on Bacterial Canker of Kiwifruit
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
Why accurate is important
Pictures: International Symposium on Bacterial Canker of Kiwifruit
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
No unnecessaryaction taken
Appropriate regulatory action
taken
Neg
ative
Positi
ve
True
val
ue
Negative Positive
Diagnosis
- Consequence -
- Trade interrupted -
Costly mitigation actions taken unnecessarily
Biosecurity breached- incursion results -
Pictures: International Symposium on Bacterial Canker of Kiwifruit
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
Plant Biosecurity: Smart Surveillance
biosecurity built on scienceScience Exchange - August 2016
Pictures: International Symposium on Bacterial Canker of Kiwifruit
Plant Biosecurity: Smart Surveillance
Pseudomonas syringae
Pseudomonas syringae
Kiwifruit Pathogen
Non-Pathogenic
Highly virulent? New?
biosecurity built on science
Psa Diagnostics
Plant Biosecurity Cooperative Research Centre
• Population level discrimination required for Psa• Very high background noise – path & nonpath pop’ns
Pseudomonas syringae pathovar actinidiae
• Many pathovars of Pseudomonas syringae• P. syringae occurs naturally on MANY plant species• P. syringae occurs naturally in rain & snow• P. syringae occurs naturally throughout the world
High potential for false positives!
Hypotheti
cal p
rotein
PsyB728a
HopAA1HrpW
1Eff
ector lo
cus p
rotein
HopM1
AvrE1
Hypotheti
cal p
rotein
Hypotheti
cal p
rotein
HrpRHrpSHrpA2En
donuclease
HrpBHrcJ HrpDHrpEHrpFHrpGHrcC HrpTHrpVHyp
othetica
l pro
tein
Hypotheti
cal p
rotein
HrcU HrcT HrcS HrcR HrcQb
HrcQa
HrpPHrpOHrcN HrpQHrcV HrpJSig
ma 70HrpK1AvrB
3HopX1HopZ3Hyp
othetica
l pro
teintRNA-Le
uqueA
Hypotheti
cal p
rotein
Psa NZ V-13
Psy ESC10
Psy ESC11
T3SS pathogenicity island
CEL Hrp/hrc cluster EEL
Sunshine Coast, Australia – 5 may 2014 – Busot, Arif, & Stack
Pathogenic strain Psy
Pathogenic strain Psa
nonPathogenic strain
nonPathogenic strain
NGS platforms: PacBio & Illumina MiSeq
• Couplets: inner ring PacBio, adjacent ring illumina
• Comparisons for errors: NGS platforms, assemblers, assembly methods (De novo and genome mapping)
• Comparative genomics: Genomic variation as a function of sequencing and assembly methods
Identification of diagnostic sequences in P. syringae pv. actinidiae
Target selection
Global outbreak
NZ LV strains
Japanese
strains
Korean
strains
Bacterial Pathovar DeterminantsEffector Gene-based diagnostics
Low virulent strains
HIGH virulent strains
Multiplex endpoint PCR-based diagnosticsGenome informed identification of diagnostic sequences in Pseudomonas syringae pv. actinidiae
Hop S2
Hop 01
Hop Z5
Hop Z5 Hop
Z3
All Psa strains
Low virulent Psa strains
High virulent Outbreak Psa strain
Determine assay sensitivity
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
PBCRC2002 & PBCRC2156• 2002: Develop & validate laboratory and field
diagnostic protocols for plant pathogenic bacteria to the pathovar level of discrimination
• 2156: Deploy validated field diagnostic protocols for plant pathogenic bacteria to the pathovar level of discrimination
• Increase national capability in plant bacteriology
GOAL: in-field detection
• Isothermal amplification technologies• Many desirable features for the field (no
heat cycling)• Very sensitive, accurate and fast!
Field deployable assays for identification of Psa
hop Z5 LAMP
hop Z3 LAMP
Loop-mediated isothermal amplification LAMP
SpecificitySensitivity
Isothermal amplification (LAMP) based diagnostics/ Genie Field deployable assays for identification of Pseudomonas syringae pv. actinidiae
With Loop primers
Without Loop primers
LAMP: 6 primers
Isothermal amplification (LAMP) based diagnostics/ThermocyclerField deployable assays for identification of Pseudomonas syringae pv. actinidiae
Ladd
er
1 23 4 5 6 7 1213 14 15 16 18 19 21 22 8 9Global outbreak/Psa V
Ladd
erPsa Psa LV
hopZ3
hopZ5
Many non Psa strainsMany Psa strains
Isothermal amplification (LAMP) based diagnostics/ThermocyclerField deployable assays for identification of Pseudomonas syringae pv. actinidiae
Alternative Visualization technologies:
■ SYBR Green
ESC-10
Psa 7 Psa 9
Psa 1
2
Psa
14
Psa 1
5
Psa 8
ESC-11
■ Lateral flow device
Internal controlPositive samples
hopZ3 + LOOP
Field deployable assays for identification of Pseudomonas syringae pv. actinidiae
Recombinase Polymerase Amplification (RPA) coupled to Lateral Flow Device
FAM-biotin/digoxigenine amplicons
Modified from Journal of Virological Methods, 2014;208:144–151
Field deployable assays for identification of Pseudomonas syringae pv. actinidiae
Isothermal amplification (RPA) based diagnostics coupled to LFD
Specificity
ESC-10
Psa 7
Psa 9
Psa 1
2Psa
14Ps
a 15
Field deployable assays for identification of Pseudomonas syringae pv. actinidiae
Sensitivity
hopZ3/RPA primers-probe
1 ng100 pg10 pg1 pg100 fg
1 fg10 fgH 2
O
Psa V
1 ng100 pg10 pg1 pg100 fg1 fg10 fgH 2
O
hopZ5/RPA primers-probe
Psa V
Isothermal amplification (RPA) based diagnostics coupled to LFD Differential sensitivity – hopZ3 and
hopZ5
Field deployable assays for identification of Pseudomonas syringae pv. actinidiae
Isothermal amplification (RPA) based diagnostics
Multiplexing with RPA? - Yes
Pictures: International Symposium on Bacterial Canker of Kiwifruit
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
All good in the lab – does it work in the field?
Field Validation & End-user TrainingAustralia - February 2016
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Victoria Kiwi Orchard
In & Out
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Victoria Kiwi Orchard – Psa?Samples: fruit, leaves, twigs
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Tailgate Diagnostics
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Moving advanced diagnostics to the fieldField-deployable technologies are here
LAMP and RPA isothermal technologies in use
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
SYBR Green visualization
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Lateral Flow Device visualization
controlpositive
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
16S bacteria general
H2O HopZ3+C
In the orchard – all good!
NO Psa in Victoria orchard!Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Victoria Kiwi Orchard – Psa?Biosecurity Staff Training
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Biosecurity Staff Technology Training
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Victoria Kiwi Orchard – Psa?Biosecurity Staff Training
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
LAMP Workshop – La Trobe University24 October 2016
Plant Biosecurity: Smart Surveillance
Pictures: J. Stack lab
Dude! This is so cool!
Even Forrest Gump can do this
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Field Validation & End-user TrainingNew Zealand - February 2016
New Zealand - February 2016Field Validation & End-user Training
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
End-User Workshop – 23 October 2016
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
End-User Workshop – 23 October 2016
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
PBCRC 2002: Genome-based, bioinformatics-informed diagnostics• Developed & validated multiple laboratory and field
diagnostic protocols for plant pathogenic bacteria to the pathovar level of discrimination
• Validated Pan-Genome Pipeline• Increased national capability in plant bacteriology:
9 scientists trained & mentored in plant bacteriology (Australia, New Zealand, U.S.)
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
PBCRC 2156: Field-deployable genome-based, bioinformatics-informed diagnostic protocols• Developed & validated multiple field-deployable
diagnostic protocols for plant pathogenic bacteria to the pathovar level of discrimination
• Validated Concept-to-Practice Pipeline• Engaged end-user communities in field testing and
validation of protocols: laboratory and in-field end-user training in new technologies and protocols
AcknowledgementsPlant Biosecurity: Smart Surveillance
Pictures: J. Stack lab
Science Exchange - August 2016
Plant Biosecurity: Smart Surveillance
Pictures: J. Stack lab
THE PBCRC Team
Science Exchange - August 2016
biosecurity built on science
Plant Biosecurity Cooperative Research Centre
James StackProfessor and Director
Genome-Informed Diagnostics
Thank you &Have a nice
day!
Field-Deployable Detection and Diagnostics - Rathayibacter toxicus
NZ Plant & Food 22 February 2016
Sample Prep
Genomic analyses of the select agent Rathayibacter toxicus
APS Annual Meeting - Tampa – 31 July 2016
NPDN National MeetingCrystal City, VA
9-10 March 2016
What’s next? Where will this technology lead us?
• The FERA SMART spore trap combines: automated loop-mediated isothermal amplification
(LAMP) analysis to identify pathogens and measure spore loads a weather station and a communication capability
(both satellite and mobile phone network) sends diagnostic and weather data to a central
facility. • Collaboration between OptiGene Ltd, Fera, The
University of Hertfordshire, Bayer Crop Science and Frontier Agriculture.
Smart, sophisticated, in-field pathogen detection with wireless communication.
NPDN National MeetingCrystal City, VA
9-10 March 2016
NextGen NPDN: A National Network with Global Implications
Smart Spore Traps
Imagine all that in a drone!
Moving advanced diagnostics to the field
LAMP isothermal technologies in use
inoculation infection colonizationreproductiondispersal
time
Path
ogen
pop
ulat
ion
critical actionpoint
diagnosticsymptoms
PCR detection limit
104
103
102
101
disease spread
More time to respond &
prevent spread