title: Infectivity of porcine circovirus type 2 DNA in semen from experimentally-infected boars.
abstract: 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.
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: Darin M
authors.initials: DM
authors.lastname: Madson
authors.forename: Sheela
authors.initials: S
authors.lastname: Ramamoorthy
authors.forename: Chris
authors.initials: C
authors.lastname: Kuster
authors.forename: Narinder
authors.initials: N
authors.lastname: Pal
authors.forename: Xiang-Jin
authors.initials: XJ
authors.lastname: Meng
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Halbur
authors.forename: Tanja
authors.initials: T
authors.lastname: Opriessnig
mesh_terms: 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
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D007074:Immunoglobulin G