Effect of coinfection with genogroup 1 porcine torque teno virus on porcine circovirus type 2-associated postweaning multisystemic wasting syndrome in gnotobiotic pigs.
OBJECTIVE
To determine whether genogroup 1 porcine torque teno virus (g1-TTV) can potentiate clinical disease associated with porcine circovirus type 2 (PCV2).


METHODS
33 gnotobiotic baby pigs.


METHODS
Pigs were allocated into 7 groups: group A, 5 uninoculated control pigs from 3 litters; group B, 4 pigs oronasally inoculated with PCV2 alone; group C, 4 pigs inoculated IP with first-passage g1-TTV alone; group D, 4 pigs inoculated IP with fourth-passage g1-TTV alone; group E, 6 pigs inoculated IP with first-passage g1-TTV and then oronasally inoculated with PCV2 7 days later; group F, 6 pigs inoculated IP with fourth-passage g1-TTV and then inoculated oronasally with PCV2 7 days later; and group G, 4 pigs inoculated oro-nasally with PCV2 and then inoculated IP with fourth-passage g1-TTV 7 days later.


RESULTS
6 of 12 pigs inoculated with g1-TTV prior to PCV2 developed acute onset of postweaning multisystemic wasting syndrome (PMWS). None of the pigs inoculated with g1-TTV alone or PCV2 alone or that were challenge exposed to g1-TTV after establishment of infection with PCV2 developed clinical illness. Uninoculated control pigs remained healthy.


CONCLUSIONS
These data implicated g1-TTV as another viral infection that facilitates PCV2-induced PMWS. This raises the possibility that torque teno viruses in swine may contribute to disease expression currently associated with only a single infectious agent.
Ellis
John A
JA
Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada.
Allan
Gordon
G
Krakowka
Steven
S
D000818:Animals; D017925:Circovirus; D004266:DNA Virus Infections / Q000662:veterinary* / Q000821:virology; D005856:Germ-Free Life; D053570:Porcine Postweaning Multisystemic Wasting Syndrome / Q000821:virology*; D013552:Swine; D022783:Torque teno virus