1, the results for 109 samples were mismatched between the two ELISAs, including four samples with positive S-ELISA results and negative M-ELISA findings along with 105 samples with negative S-ELISA results and positive M-ELISA results. correlation between data from the two ELISAs. Results from the farms with pigs vaccinated (R)-ADX-47273 with the three different PCV2 vaccines demonstrated that most of the vaccinated animals underwent seroconversion. However, the increase and duration of antibody titers varied depending on the vaccine, the presence of maternal antibodies, and the vaccination program. PCV2 serologic status and anti-PCV2 antibody levels of herds from this study could be utilized to determine the best timing for vaccination and assessing vaccination compliance. Keywords: enzyme-linked immunosorbent assay, pigs, porcine circovirus 2, serology Introduction Porcine circovirus (PCV; family values <0.05 were considered significant. Results For a total of 517 serum samples, 371 (71.8%) and 472 (91.3%) had positive S-ELISA and M-ELISA results, respectively. The two ELISA assays were fully concordant for 365 positive and 42 negative (including 14 false-positive results obtained with the M-ELISA) samples, indicating 78.7% agreement for the ELISA results. There was a moderate correlation (Pearson = -0.636, < 0.001) between the M-ELISA results and square-root transformed S-ELISA results, indicating a linear relationship (y = -0.175x + 0.787, R2 = 0.405; Fig. 1). As shown in Fig. 1, the results for 109 samples were mismatched between the two ELISAs, including four samples with positive S-ELISA results and negative M-ELISA findings along with 105 samples with negative S-ELISA results and positive M-ELISA results. The majority of mismatches were negative for the S-ELISA and positive for the M-ELISA, which were in 0.6 S/N ratio > 0.4 of S-ELISA and 1.2 > S/P ratio 0.4 of M-ELISA. Open in a separate window Fig. 1 Comparison of data from the two available enzyme-linked immunosorbent assay (ELISA) kits using 517 field-collected pig sera. ELISA index values of the S-ELISA were square-root transformed. The regression equation is: y = -0.175x + 0.787; R-square = 0.405, < 0.001. PCV2-specific antibodies were identified in pigs vaccinated with the three different PCV2 vaccines (I, II, and III) using two commercially available ELISA kits. With vaccination, antibody titers against PCV2 were increased in most of the animals. However, the increase and duration of the antibody titer varied depending on the vaccine, presence of maternal antibodies, and vaccination program. Agreement between the ELISAs based on the vaccines was also assessed, and was 76%, 73.9%, or 83% for the pigs given the vaccine I, II, and III, respectively. In addition, results of the ELISAs had a moderate correlation (vaccine I, Pearson's = -0.602, < 0.001; vaccine II, = -0.672, < 0.001; vaccine III, = -0.621, < 0.001) and a linear relationship (vaccine I, y = -0.183x + 0.806, R2 = 0.362; vaccine II, y = -0.191x + 0.815, R2 = 0.451; vaccine III, y = -0.158x + 0.759, R2 = 0.386, < 0.001) according to the vaccine (panel B in Fig. (R)-ADX-47273 2). Open in a separate window Fig. 2 Detection of PCV2-specific antibodies in field pig serum samples from animals of different ages using two commercial ELISA kits. Anti-PCV2 antibodies were verified in samples from farms with pigs vaccinated with three different PCV2 vaccines (I, II, and III) using commercially available ELISA kits (S and M). The levels of PCV2-specific antibodies are shown in a box-and-whisker plot graph displaying the minimum, first quartile, median, third quartile, and maximum. The dotted lines indicate the median level for each farm. The y-axis represents the S/N ratio and S/P ratio for the S-ELISA and M-ELISA, respectively. Pigs administered I vaccine had different ELISA results at 20 and 70 days of age. The S-ELISA produced negative results at 20 days of age before the antibody levels gradually increased. The M-ELISA produced positive results at 20 days of age before the levels gradually increased after a sudden decline at 70 days of age. For the pigs given vaccine II, the M-ELISA results were positive at all ages and indicated that a seroconversion occurred after the second vaccination. The S-ELISA results showed that antibody levels gradually increased, but the results for some farms (Farm 5) indicated that antibody levels decreased after vaccination. A slight decrease of antibody levels occurred at Rabbit Polyclonal to IRX3 40 days of age according to the results of both ELISAs. Pigs treated with the vaccine III showed a gradual increase in antibody levels according to both ELISAs with a significant decrease at 40 days of age based on the S-ELISA findings. Discussion Vaccination is an attractive measure for controlling PCV2-associated diseases. Therefore, methods for measuring anti-PCV2 antibodies have been developed and applied to field samples. Serum-virus neutralization, immunoperoxidase monolayer, and indirect (R)-ADX-47273 immunofluorescent assays have.