Infectivity of porcine circovirus type 2 DNA in semen from experimentally-infected boars

Vet Res. 2009 Jan-Feb;40(1):10. doi: 10.1051/vetres:2008048. Epub 2008 Oct 31.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Viral / blood
  • Biological Assay / veterinary
  • Circoviridae Infections / transmission
  • Circoviridae Infections / veterinary*
  • Circoviridae Infections / virology
  • Circovirus / classification
  • Circovirus / genetics
  • Circovirus / immunology
  • Circovirus / isolation & purification*
  • DNA, Viral / isolation & purification*
  • Female
  • Immunoglobulin G / blood
  • Insemination, Artificial / standards
  • Insemination, Artificial / veterinary*
  • Male
  • Random Allocation
  • Semen / virology*
  • Swine
  • Swine Diseases / transmission*
  • Swine Diseases / virology
  • Virus Shedding

Substances

  • Antibodies, Viral
  • DNA, Viral
  • Immunoglobulin G