Reactivation of latent pseudorabies virus infection in vaccinated commercial sows.
Pseudorabies virus (PRV) was isolated from 9 of 44 PRV-vaccinated seropositive sows on 5 of 11 farms. Although serum-neutralization antibody titers were 1:16 to 1:256, 28 virus isolates were obtained from tonsil, nasal, or buccal swab samples from 9 sows given 2 ml of dexamethasone/kg of body weight IM for 5 days. Pseudorabies virus was isolated from 6 of 20 sows (3 of 5 farms) given a killed-virus vaccination. Virus was obtained from 3 of 24 sows (2 of 6 farms) given modified-live virus and killed-virus vaccination. Evaluation of the 9 PRV with 5 restriction endonucleases revealed 4 PRV existing genotypes. The 9 isolated types of PRV appeared to be indistinguishable by Kpn I and BamHI restriction endonuclease analysis; however, when analyzed with Sal I, HinfI, and Pst I, isolates 7 (farm D), 8 (farm C), and 9 (farm B) had numerous differences. Isolates 1, 2, 3, and 4 (farm F) and 5 and 6 (farm G) appeared to be the same genotype when further analyzed with Pst I, HinfI, and Sal I.
Cowen
P
P
Department of Microbiology, Pathology and Parasitology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606.
Li
S
S
Guy
J S
JS
Erickson
G A
GA
Blanchard
D
D
D000818:Animals; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D011558:Herpesvirus 1, Suid / Q000235:genetics / Q000254:growth & development*; D011557:Pseudorabies / Q000382:microbiology* / Q000517:prevention & control; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology* / Q000517:prevention & control; D013997:Time Factors; D014611:Vaccination / Q000662:veterinary; D015164:Vaccines, Inactivated; D014775:Virus Activation / Q000187:drug effects*
D004279:DNA, Viral; D015164:Vaccines, Inactivated; D003907:Dexamethasone; D004262:DNA Restriction Enzymes