PMID- 24756023
OWN - NLM
STAT- MEDLINE
DCOM- 20150120
LR  - 20211021
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 9
IP  - 4
DP  - 2014
TI  - Variation in fetal outcome, viral load and ORF5 sequence mutations in a large 
      scale study of phenotypic responses to late gestation exposure to type 2 porcine 
      reproductive and respiratory syndrome virus.
PG  - e96104
LID - 10.1371/journal.pone.0096104 [doi]
LID - e96104
AB  - In spite of extensive research, the mechanisms of reproductive disease associated 
      with Porcine Reproductive and Respiratory Syndrome virus (PRRSv) are still poorly 
      understood. The objectives of this large scale study were to evaluate 
      associations between viral load and fetal preservation, determine the impact of 
      type 2 PRRSv on fetal weights, and investigate changes in ORF5 PRRSv genome in 
      dams and fetuses during a 21-day period following challenge. At gestation day 85 
      (+/-1), 114 gilts were experimentally infected with type 2 PRRSv, while 19 gilts 
      served as reference controls. At necropsy, fetuses were categorized according to 
      their preservation status and tissue samples were collected. PRRSv RNA 
      concentrations were measured in gilt serum collected on days 0, 2, 6, and 21 
      post-infection, as well as in gilt and fetal tissues collected at termination. 
      Fetal mortality was 41+/-22.8% in PRRS infected litters. Dead fetuses appeared to 
      cluster in some litters but appeared solitary or random in others. Nine percent 
      of surviving piglets were meconium-stained. PRRSv RNA concentration in fetal 
      thymus, fetal serum and endometrium differed significantly across preservation 
      category and was greatest in tissues of meconium-stained fetuses. This, together 
      with the virtual absence of meconium staining in non-infected litters indicates 
      it is an early pathological condition of reproductive PRRS. Viral load in fetal 
      thymus and in fetal serum was positively associated with viral load in 
      endometrium, suggesting the virus exploits dynamic linkages between individual 
      maternal-fetal compartments. Point mutations in ORF5 sequences from gilts and 
      fetuses were randomly located in 20 positions in ORF5, but neither nucleotide nor 
      amino acid substitutions were associated with fetal preservation. PRRSv infection 
      decreased the weights of viable fetuses by approximately 17%. The considerable 
      variation in gilt and fetal outcomes provides tremendous opportunity for more 
      detailed investigations of potential mechanisms and single nucleotide 
      polymorphisms associated with fetal death.
FAU - Ladinig, Andrea
AU  - Ladinig A
AD  - Department of Large Animal Clinical Sciences, Western College of Veterinary 
      Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
FAU - Wilkinson, Jamie
AU  - Wilkinson J
AD  - Department of Agricultural, Food, and Nutritional Science, Faculty of 
      Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, 
      Alberta, Canada.
FAU - Ashley, Carolyn
AU  - Ashley C
AD  - Department of Large Animal Clinical Sciences, Western College of Veterinary 
      Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
FAU - Detmer, Susan E
AU  - Detmer SE
AD  - Department of Veterinary Pathology, Western College of Veterinary Medicine, 
      University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
FAU - Lunney, Joan K
AU  - Lunney JK
AD  - Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, 
      Agricultural Research Service, U.S. Department of Agriculture, Beltsville, 
      Maryland, United States of America.
FAU - Plastow, Graham
AU  - Plastow G
AD  - Department of Agricultural, Food, and Nutritional Science, Faculty of 
      Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, 
      Alberta, Canada.
FAU - Harding, John C S
AU  - Harding JC
AD  - Department of Large Animal Clinical Sciences, Western College of Veterinary 
      Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20140422
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - 0 (RNA, Viral)
RN  - 0 (Viral Envelope Proteins)
RN  - 0 (glycoprotein 5, PRRSV)
SB  - IM
MH  - Abortion, Veterinary/*virology
MH  - Animals
MH  - Endometrium/virology
MH  - Female
MH  - Fetal Weight
MH  - Genetic Association Studies
MH  - Genotype
MH  - Gestational Age
MH  - Phenotype
MH  - Polymorphism, Single Nucleotide
MH  - Porcine Reproductive and Respiratory Syndrome/mortality/*virology
MH  - Porcine respiratory and reproductive syndrome virus/*genetics
MH  - Pregnancy
MH  - RNA, Viral/genetics
MH  - Sequence Analysis, DNA
MH  - Sus scrofa
MH  - Swine
MH  - Thymus Gland/virology
MH  - Viral Envelope Proteins/*genetics
MH  - Viral Load
PMC - PMC3996001
COIS- Competing Interests: The authors have declared that no competing interests exist.
EDAT- 2014/04/24 06:00
MHDA- 2015/01/21 06:00
PMCR- 2014/04/22
CRDT- 2014/04/24 06:00
PHST- 2014/02/21 00:00 [received]
PHST- 2014/04/03 00:00 [accepted]
PHST- 2014/04/24 06:00 [entrez]
PHST- 2014/04/24 06:00 [pubmed]
PHST- 2015/01/21 06:00 [medline]
PHST- 2014/04/22 00:00 [pmc-release]
AID - PONE-D-14-04030 [pii]
AID - 10.1371/journal.pone.0096104 [doi]
PST - epublish
SO  - PLoS One. 2014 Apr 22;9(4):e96104. doi: 10.1371/journal.pone.0096104. eCollection 
      2014.