title: Evaluation of an egg yolk enzyme-linked immunosorbent assay antibody test and its use to assess the prevalence of Mycoplasma synoviae in UK laying hens.
abstract: The frequency of Mycoplasma synoviae exposure in a convenience sample of commercial layers was established by the presence of antibody in eggs. Chloroform-extracted egg yolks were found to be more suitable than saline-extracted yolks, and were used with a commercial enzyme-linked immunosorbent assay kit, having first established the sensitivity and specificity of the kit with eggs from known M. synoviae-positive and M. synoviae-negative flocks. For the prevalence study, pooled yolks from 12 eggs were obtained from each of 56 randomly selected laying farms in possession of a packing station number in the east of England. This number allowed 95% confidence of detection of antibody in one egg if present in 50% of the flock. Eggs were taken from the oldest flock on each site and were returned with a completed questionnaire. The prevalence of egg antibody to M. synoviae was 78.6% (95% confidence interval, 65.6, 88.4). This study has confirmed that chloroform extraction of yolk antibody is a suitable approach for assessing the flock prevalence of M. synoviae infection in layer hens.
authors.affiliation: Department of Veterinary Pathology, University of Liverpool, Leahurst, Neston, UK. jhagan@liverpool.ac.uk
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Hagan
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Ashton
authors.forename: Janet M
authors.initials: JM
authors.lastname: Bradbury
authors.forename: Kenton L
authors.initials: KL
authors.lastname: Morgan
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D002645:Chickens; D002725:Chloroform; D016001:Confidence Intervals; D004530:Egg Yolk / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005260:Female; D009175:Mycoplasma Infections / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D045805:Mycoplasma synoviae / Q000276:immunology*; D010865:Pilot Projects; D011201:Poultry Diseases / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D011897:Random Allocation; D012680:Sensitivity and Specificity; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000907:Antibodies, Bacterial; D002725:Chloroform