title: Serologic profiling of Haemophilus parasuis-vaccinated sows and their litters using a novel oligopeptide permease A enzyme-linked immunosorbent assay reveals unexpected patterns of serological response and maternal antibody transfer.
abstract: Haemophilus parasuis is an economically important swine pathogen with 15 recognized serovars. An enzyme-linked immunosorbent assay (ELISA) was developed that detects serum antibodies to the oligopeptide permease A (OppA) polypeptide membrane protein present in the reference strains for 13 of the H. parasuis serovars. Using the OppA-ELISA, H. parasuis serologic profiles were assessed on 2 swine farms, with seroconversion defined as an OppA-ELISA sample-to-positive (S/P) ratio ≥0.5. Ten gilts from each farm were vaccinated for H. parasuis using either a live avirulent culture vaccine (farm 1) or an inactivated autogenous vaccine (farm 2). Seroconversion occurred in 100% of farm 1 gilts and 90% of farm 2 gilts, with a mean S/P ratio (MSPR) of 3.36 and 1.43, respectively. The OppA-ELISA MSPRs were determined for 2 piglets, 1 male and 1 female, randomly selected from 10 first-parity (P1), 10 second-parity (P2), and 10 third-parity (P3) litters farrowed by respective vaccinated gilts on each farm. On both farms, postfarrowing MSPRs and rate of seropositivity were highest in P1 versus P2 and P3 dams. Parity 1 piglets had higher MSPRs and rates of seropositivity versus later parities, with the difference being significant (P < 0.05) on farm 2. Polymerase chain reaction analysis of nasal swabs indicated that 100% of farm 1 piglets and 47-84%, depending on parity, of farm 2 piglets were H. parasuis-colonized at weaning. The results indicated that H. parasuis vaccination of gilts will not maintain serologic responses in the OppA-ELISA over their reproductive lifetimes, and that maternally derived antibodies do not prevent H. parasuis colonization of piglets.
authors.affiliation: 1Lucina Galina Pantoja, Team Pork Veterinary Services, Zoetis, 100 Campus Drive, 4th Floor W4785, Florham Park, NJ 07932. lucina.galina@zoetis.com.
authors.forename: Lucina
authors.initials: L
authors.lastname: Galina Pantoja
authors.forename: Bethany
authors.initials: B
authors.lastname: Stammen
authors.forename: Bill
authors.initials: B
authors.lastname: Minton
authors.forename: Deborah
authors.initials: D
authors.lastname: Amodie
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins; D001428:Bacterial Vaccines / Q000592:standards; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005260:Female; D006192:Haemophilus Infections / Q000097:blood / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D044137:Haemophilus parasuis / Q000235:genetics / Q000276:immunology*; D007112:Immunity, Maternally-Acquired / Q000276:immunology*; D008297:Male; D026901:Membrane Transport Proteins; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011247:Pregnancy; D011897:Random Allocation; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000382:microbiology*; D014611:Vaccination / Q000662:veterinary
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D026901:Membrane Transport Proteins; C037230:oligopeptide permease, Bacteria
keywords: Haemophilus parasuis; oligopeptide permease A; serologic; swine; universal enzyme-linked immunosorbent assay