title: Use of a novel serum ELISA method and the tonsil-carrier state for evaluation of Mycoplasma hyosynoviae distributions in pig herds with or without clinical arthritis.
abstract: A novel indirect ELISA test using deoxycholate extracted antigens coated onto a hydrophobic polystyrene surface for measurement of serum antibodies specific for Mycoplasma hyosynoviae was developed. Sensitivity and specificity of the test were found to be superior to previous ELISAs as tested on porcine serum following experimental Mycoplasma infections as well as by analysis of samples from one Danish herd known to be free of M. hyosynoviae and samples from two Norwegian herds without clinical suspicion of M. hyosynoviae infections since their establishment. The epidemiology of M. hyosynoviae infection was then investigated in Danish pig herds with evidence of clinical M. hyosynoviae arthritis (MhA herds, n = 4) and in herds with M. hyosynoviae-carriers among slaughter pigs, but with limited clinical lameness (MhC herds, n = 4). M. hyosynoviae bacteriaemia and tonsil-carrier state were determined by culture of cross-sectional samples of whole-blood (n = 238) and tonsil scrapings (n = 322), respectively. Levels of serum antibodies (n = 396) were measured by the novel indirect ELISA test. There was no significant difference in the ELISA results between the MhA and the MhC herds. Pigs that were tonsil-carriers had a significantly higher response in the ELISA test (P < 0.001) than non-carriers. Slaughter pigs showed higher ELISA values (P < 0.001) and they were more prone to be tonsil-carriers (P < 0.001). The most critical period for spread of the infection seems to be the nursery period (4-12 weeks). The results indicate that M. hyosynoviae infection progresses similarly in herds irrespective of the presence of clinical arthritis. Thus, clinical arthritis due to M. hyosynoviae is probably triggered by other host or herd factors than low levels of serum antibodies or by differences in virulence factors between M. hyosynoviae strains.
authors.affiliation: The National Committee for Pig Production, Danish Bacon and Meat Council, Axeltorv 3, 1609 Copenhagen V, Denmark. eon@danishmeat.dk
authors.forename: Elisabeth Okholm
authors.initials: EO
authors.lastname: Nielsen
authors.forename: Klara Tølbøll
authors.initials: KT
authors.lastname: Lauritsen
authors.forename: Niels Filskov
authors.initials: NF
authors.lastname: Friis
authors.forename: Claes
authors.initials: C
authors.lastname: Enøe
authors.forename: Tine
authors.initials: T
authors.lastname: Hagedorn-Olsen
authors.forename: Gregers
authors.initials: G
authors.lastname: Jungersen
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000907:Antibodies, Bacterial / Q000097:blood; D001170:Arthritis, Infectious / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D002353:Carrier State / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D009175:Mycoplasma Infections / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D045791:Mycoplasma hyosynoviae / Q000276:immunology*; D009664:Norway / Q000453:epidemiology; D014066:Palatine Tonsil / Q000382:microbiology; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis* / Q000453:epidemiology; D037521:Virulence Factors
chemical_list: D000907:Antibodies, Bacterial; D037521:Virulence Factors