Characterization of shedding patterns of Porcine circovirus types 2a and 2b in experimentally inoculated mature boars.
Porcine circovirus-2 (PCV-2) is an economically important swine pathogen and causes PCV-associated disease (PCVAD) in pigs worldwide. Currently, 2 genotypes of PCV-2, PCV-2a and -2b, are circulating in U.S. swine herds. The objectives of the current study were to evaluate the amount of PCV-2 DNA present in semen over time, compare and correlate incidence and amount of PCV-2 present in semen samples to that present in serum samples and blood swabs, and determine if there are differences in shedding patterns between PCV-2a and -2b. Fifteen 7-month-old PCV-2-naïve Landrace boars (Sus scrofa) were randomly allocated to 3 treatment groups. The boars in group 1 (n = 3) served as negative controls, and those in groups 2 (n = 6) and 3 (n = 6) were intranasally and intramuscularly inoculated with PCV-2a and -2b, respectively. Semen, serum, and blood swab samples were collected up to 90 days postinoculation (DPI), and necropsies were performed on DPI 23, 48, and 90. Larger quantities of both PCV-2a and -2b DNA were detected earlier in serum and blood swab samples than in raw semen of experimentally inoculated boars. The incidence and duration of presence of PCV-2 DNA in semen varied among boars; however, intermittent shedding was not observed. In all sex glands, PCV-2 DNA was detected by polymerase chain reaction; however, PCV-2 antigen was not detected by immunohistochemistry, and PCV-2 had no effect on sperm morphology. Differences in shedding patterns between PCV-2a and -2b were not observed under the study conditions.
Madson
Darin M
DM
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
Ramamoorthy
Sheela
S
Kuster
Chris
C
Pal
Narinder
N
Meng
Xiang-Jin
XJ
Halbur
Patrick G
PG
Opriessnig
Tanja
T
D000818:Animals; D001769:Blood / Q000821:virology; D018173:Circoviridae Infections / Q000662:veterinary; D017925:Circovirus / Q000302:isolation & purification*; D004277:DNA, Single-Stranded / Q000235:genetics / Q000302:isolation & purification; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D016679:Genome, Viral; D008297:Male; D016133:Polymerase Chain Reaction; D012661:Semen / Q000821:virology; D013552:Swine / Q000821:virology*; D013553:Swine Diseases / Q000821:virology; D017201:Virus Shedding / Q000502:physiology*
D004277:DNA, Single-Stranded; D004279:DNA, Viral