PRRSV Evolution and New, Emerging Strains
Michael MurtaughXiong WangMohammad AlkhamisBob MorrisonAndres Perez
University of Minnesota
There are Two General Types of PRRSVType 1
(European)Type 2
(North American)
ORF5 Dendrogram
Lineage 1
Lineage 2Lineage 5.1Lineage 5.2
Lineage 6,7
Lineage 9
Lineage 8Type 2 PRRSV
Diversity ORF5
Lineage 1
Lineage 2Lineage 5.1Lineage 5.2
Lineage 6,7
Lineage 9
Lineage 8
1-8-4
1-7-4
2-5-2
1-4-2
1-4-2
HP PRRSType 2 PRRSV
Diversity ORF5
Type 2 PRRSV Diversity Whole Genome
HP PRRS
Ingelvac MLVReisolates Conclusions: Genbank sampling is
highly biased. No naming system.
Mlu I HincII Sac II
1 8 41 18 2
2 5 2
1 26 2
ORF50 100 200 300 400 500 600
Here are some common PRRSV RFLP types
Year 2010
1-4
1-55
1-8
March 302015 1-4 1-114 1-12
November 172015 1-5 1-125 1-13
RFLP pattern does not identify genetic relationships
1-4-4 RFLP shows up in 3 widely divergent families
Ecology of PRRSV
6774 PRRSV isolates1998-2015
Type 1N=107 (1.6%)15 years of PRRSV
Diagnostic Sequencing in USA
5 Large US SwineProducers
98.4% are Type 2
Conclusions: Large outbreaks with little
genetic change are frequent Control programs are effective Genbank does not show reality
Chinese HP-PRRSV
2006-2009 >99% identical
2006-2011 >98% identical
Type 2 PRRSV
Type 1 PRRSV One System160 ORF5 sequences
+ References
Type 2 Only
Apr 1, 2012–Jun 17, 2013
1-4-41-4-41-4-4
1-4-4
1-4-4 1-4-4
1-4-4 Outbreaks
May 21, 2014–March 31, 2015
1-7-4
1-7-4
1-7-4
1-7-4
1-7-4 Outbreaks
May 21, 2014–March 31, 2015
1-7-4
1-7-4
1-7-4
1-7-41-4-41-6-4
1-6-4
1-7-3
1-21-4
1-7-4 OutbreaksSame virus – Multiple RFLP patterns
1-7-4-PRRSV Family Story
241 1-7-4 familyJan 2014 -Mar 2015
47 n
on-1
74 fa
mily
Sept
embe
r 200
3-M
arch
2015
6774 sequences1998-2015
Anatomy of Disaster1-7-4 Outbreaks Investigation
Jun 2014Jun 2014
May 2014Apr 2014
Jun 2014Sep 2014
Dec 2014
Jan 2015
Jan 2015
The Devil’s SpawnDistant Offspring of the 1-8-4 Family
nsp2 Deletions are Unremarkable
No other distinctive features are apparent
Signal Peptide Ectodomain 1 TM Ectodomain 2
Proteins are Essentially the SameEnvelope Glycoprotein 5 (GP5)
No evidence of directed evolution or selection during outbreak
Bayesian PhylodynamicsSkyline Plot of Estimated Population Size over Time
Bayesian phylogenetic methods incorporate associated epidemiological information (e.g. geographic location, time of isolation)
History of Spread Between Systems
Outbreaks are Concentrated in Sow Farms
Dynamic representation
Shields and Mathews (2003). Interstate Livestock Movements. USDA-Economic Research Service Outlook Reportwww.ers.usda.gov/publicatons/ldp/jun03/ldpm10801/ldpm10801.pdf.
A B
Swine outflows from North Carolina Swine inflows to Minnesota
Interstate pig movements in the U.S.A. in 2001
Take Home Messages
Large-scale PRRS outbreaks in the history of type 2 PRRSV
Genetic change during outbreaks is limited
Bayesian phylodynamics helps understand disease spread
PRRSV goes where pigs go
Top Related