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Evaluation of porcine epidemic diarrhea virus transmission and the immune response in growing pigs.

Crawford K, Lager K, Miller L, Opriessnig T, Gerber P, Hesse R - Vet. Res. (2015)

Bottom Line: On Day 0 (D0), a growing pig was challenged with PEDV and 13 contacts were commingled.By D63, all N/C seroconverted.This demonstrates potential for an effective PEDV vaccine.

View Article: PubMed Central - PubMed

Affiliation: National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, USA. Kimberly.crawford@ars.usda.gov.

ABSTRACT
Clinical disease associated with porcine epidemic diarrhea virus (PEDV) infection in naïve pigs is well chronicled; however, information on endemic PEDV infection is limited. To characterize chronic PEDV infection, the duration of infectious virus shedding and development of protective immunity was determined. On Day 0 (D0), a growing pig was challenged with PEDV and 13 contacts were commingled. On D7, 9 contact pigs (principal virus group (PG)), were selected, moved to a separate room and commingled with one sentinel pig (S1). This process was repeated weekly with S2, S3 and S4. The PG was PEDV-positive by PCR from D3-11, with some pigs intermittently positive to D42. Pigs S1 and S2 were PEDV-positive within 24 hours of commingling. Antibodies were detected in all PG by D21 and by 7 days post-contact in S1 and S2. Pigs S3 and S4 were PCR and antibody negative following commingling. To evaluate protective immunity, 5 naïve pigs (N) and the PG were challenged (N/C, PG/C) with homologous virus on D49. All N/C pigs were PEDV PCR-positive by D52 with detection out to D62 in 3/5 N/C pigs. All PG/C pigs were PEDV PCR-negative post-challenge. By D63, all N/C seroconverted. Although PEDV RNA was demonstrated in pigs after primary infection until D42, infectious PEDV capable of horizontal transmission to naïve pigs was only shed 14-16 days after infection to age-matched pigs. Homologous re-challenge 49 days post initial PEDV exposure did not result in re-infection of the pigs. This demonstrates potential for an effective PEDV vaccine.

No MeSH data available.


Related in: MedlinePlus

Average Optical Density (OD) of IgG antibody to PEDV. Average (OD) of IgG Antibody to PEDV over time in the Stationary Group without seeder pig included (SG - seeder), Seeder pig, Principal Group (PG), and Naïve/Challenge (N/C) group. On D 49, PG and N/C pigs orally challenged with PEDV strain USA/Colorado/2013. Dashed line represents cut-off optical density value of 0.3.
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Fig2: Average Optical Density (OD) of IgG antibody to PEDV. Average (OD) of IgG Antibody to PEDV over time in the Stationary Group without seeder pig included (SG - seeder), Seeder pig, Principal Group (PG), and Naïve/Challenge (N/C) group. On D 49, PG and N/C pigs orally challenged with PEDV strain USA/Colorado/2013. Dashed line represents cut-off optical density value of 0.3.

Mentions: In the PG group, 2/9, 8/9, and 9/9 pigs were positive for PEDV-antibodies by D7, 14, and 21, respectively. In the N/C group, 2/5 pigs were ELISA positive by D56 (7 days post challenge) and all pigs were positive from D63 to D78. S1 and S2 seroconverted by 7 days post-contact and S3 and S4 remained seronegative throughout the remainder of the study. Average ELISA OD readings for the PG, SG, and N/C groups are depicted in Figure 2.Figure 2


Evaluation of porcine epidemic diarrhea virus transmission and the immune response in growing pigs.

Crawford K, Lager K, Miller L, Opriessnig T, Gerber P, Hesse R - Vet. Res. (2015)

Average Optical Density (OD) of IgG antibody to PEDV. Average (OD) of IgG Antibody to PEDV over time in the Stationary Group without seeder pig included (SG - seeder), Seeder pig, Principal Group (PG), and Naïve/Challenge (N/C) group. On D 49, PG and N/C pigs orally challenged with PEDV strain USA/Colorado/2013. Dashed line represents cut-off optical density value of 0.3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4419466&req=5

Fig2: Average Optical Density (OD) of IgG antibody to PEDV. Average (OD) of IgG Antibody to PEDV over time in the Stationary Group without seeder pig included (SG - seeder), Seeder pig, Principal Group (PG), and Naïve/Challenge (N/C) group. On D 49, PG and N/C pigs orally challenged with PEDV strain USA/Colorado/2013. Dashed line represents cut-off optical density value of 0.3.
Mentions: In the PG group, 2/9, 8/9, and 9/9 pigs were positive for PEDV-antibodies by D7, 14, and 21, respectively. In the N/C group, 2/5 pigs were ELISA positive by D56 (7 days post challenge) and all pigs were positive from D63 to D78. S1 and S2 seroconverted by 7 days post-contact and S3 and S4 remained seronegative throughout the remainder of the study. Average ELISA OD readings for the PG, SG, and N/C groups are depicted in Figure 2.Figure 2

Bottom Line: On Day 0 (D0), a growing pig was challenged with PEDV and 13 contacts were commingled.By D63, all N/C seroconverted.This demonstrates potential for an effective PEDV vaccine.

View Article: PubMed Central - PubMed

Affiliation: National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, USA. Kimberly.crawford@ars.usda.gov.

ABSTRACT
Clinical disease associated with porcine epidemic diarrhea virus (PEDV) infection in naïve pigs is well chronicled; however, information on endemic PEDV infection is limited. To characterize chronic PEDV infection, the duration of infectious virus shedding and development of protective immunity was determined. On Day 0 (D0), a growing pig was challenged with PEDV and 13 contacts were commingled. On D7, 9 contact pigs (principal virus group (PG)), were selected, moved to a separate room and commingled with one sentinel pig (S1). This process was repeated weekly with S2, S3 and S4. The PG was PEDV-positive by PCR from D3-11, with some pigs intermittently positive to D42. Pigs S1 and S2 were PEDV-positive within 24 hours of commingling. Antibodies were detected in all PG by D21 and by 7 days post-contact in S1 and S2. Pigs S3 and S4 were PCR and antibody negative following commingling. To evaluate protective immunity, 5 naïve pigs (N) and the PG were challenged (N/C, PG/C) with homologous virus on D49. All N/C pigs were PEDV PCR-positive by D52 with detection out to D62 in 3/5 N/C pigs. All PG/C pigs were PEDV PCR-negative post-challenge. By D63, all N/C seroconverted. Although PEDV RNA was demonstrated in pigs after primary infection until D42, infectious PEDV capable of horizontal transmission to naïve pigs was only shed 14-16 days after infection to age-matched pigs. Homologous re-challenge 49 days post initial PEDV exposure did not result in re-infection of the pigs. This demonstrates potential for an effective PEDV vaccine.

No MeSH data available.


Related in: MedlinePlus