Prolonged Detection of PCV2 and Anti-PCV2 Antibody inOral Fluids Following Experimental Inoculation

摘要

The onset, level and duration of PCV2 and anti-PCV2 antibody in oral fluidwere evaluated using samples collected from experimentally inoculated pigs for98 days post-inoculation (DPI). Pigs (n = 24) were obtained at 3 weeks of ageand randomly allocated to 4 treatment pens of 6 pigs each: (i) negative controlgroup; (ii) inoculated with PCV2a (strain ISU 40895) on DPI 0; (iii) inoculatedwith PCV2a (strain ISU-40895) on DPI 0 and re-challenged at DPIs 35 and 70;(iv) inoculated with PCV2a (ISU-40895), PCV2b (PVG4072) and PCV2a (ISU-4838) on DPIs 0, 35 and 70, respectively. Serum was collected from each animal,and one oral fluid sample was collected from each pen (group) everyother day from DPI 2 through DPI 14 and weekly through 98 DPI. Oral fluidsamples were assayed for the presence of PCV2 by quantitative polymerasechain reaction (qPCR) and anti-PCV2 IgG, IgA and IgM antibody isotypes byenzyme-linked immunosorbant assay (ELISA). Serum was assayed for anti-PCV2 IgG by ELISA. Anti-PCV2 antibodies (IgG, IgM and IgA) were detectedin oral fluid from experimentally inoculated pigs from DPI 14 with IgG andIgA clearly present at 98 DPI. PCV2 was detected in oral fluid samples from allpens of inoculated pigs at 2 DPI. Thereafter, PCV2 was detected in oral fluidthroughout 98 DPI. Overall, the data indicated that PCV2 infection in swine isprolonged, persists in the face of an active antibody response and can be efficientlymonitored using oral fluid specimens.