Infectivity of porcine circovirus type 2 DNA in semen from experimentally-infected boars.
Porcine circovirus type 2 (PCV2) is an economically important pathogen. It has been demonstrated that PCV2 DNA can be detected in boar semen by PCR; however, the biological relevance of this is unknown. The objectives of this study were to determine if semen positive for PCV2 DNA is infectious (1) in a swine bioassay, or (2) when used for artificial insemination. For the first objective, 4-week-old pigs were inoculated intraperitoneally with PCV2 DNA-negative (bioassay-control; n = 3), PCV2a DNA-positive (bioassay-PCV2a; n = 3), or PCV2b DNA-positive (bioassay-PCV2b; n = 3) raw semen, or PCV2 live virus (bioassay-positive; n = 3), respectively. Pigs inoculated with PCV2 DNA-positive semen and PCV2 live virus became viremic and developed anti-PCV2 antibodies indicating that the PCV2 DNA present in semen was infectious. For the second objective, three Landrace gilts were inseminated with PCV2 DNA-negative semen (gilts-controls) from experimentally-infected boars, and six gilts were artificially inseminated with semen positive for PCV2a DNA (gilts-PCV2a; n = 3) or PCV2b DNA (gilts-PCV2b; n = 3). Serum samples collected from the gilts in all groups remained negative for anti-PCV2 antibodies for the duration of the experiment. In addition, fetal serum samples from all 105-day-gestation fetuses were negative for anti-PCV2 antibodies or PCV2 DNA. Under the conditions of this study, PCV2 DNA-positive semen was not infectious when used to artificially inseminate gilts; however, it was demonstrated to be infectious in a swine bioassay model and therefore is a potential means of PCV2 transmission amongst swine herds.
Madson
Darin M
DM
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
Ramamoorthy
Sheela
S
Kuster
Chris
C
Pal
Narinder
N
Meng
Xiang-Jin
XJ
Halbur
Patrick G
PG
Opriessnig
Tanja
T
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001681:Biological Assay / Q000662:veterinary; D018173:Circoviridae Infections / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D004279:DNA, Viral / Q000302:isolation & purification*; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D007315:Insemination, Artificial / Q000592:standards / Q000662:veterinary*; D008297:Male; D011897:Random Allocation; D012661:Semen / Q000821:virology*; D013552:Swine; D013553:Swine Diseases / Q000635:transmission* / Q000821:virology; D017201:Virus Shedding
D000914:Antibodies, Viral; D004279:DNA, Viral; D007074:Immunoglobulin G