title: Peptides specific for Mycobacterium avium subspecies paratuberculosis infection: diagnostic potential.
abstract: Mycobacterium avium subspecies paratuberculosis (Map) is the causative agent of Johne's disease (JD). Current serological diagnostic tests for JD are limited by their sensitivity when used in sub-clinical stages of the disease. Our objective was to identify peptides that mimic diagnostically important Map epitopes that might be incorporated into a new-generation JD diagnostic. Four peptides were isolated from a phage-displayed random peptide library by screening on antibodies derived from Map-infected goats. The peptides were recognised by antibodies from Map-infected goats but not by antibodies from uninfected goats. The peptides elicited immune responses in rabbits, which reacted strongly with bona fide Map antigens proving the peptides were true epitope mimics. To assess the diagnostic value a panel of goat sera was screened for reactivity's with peptides. The peptides were recognised by antibodies from a proportion of goats infected with Map compared with control animals with a diagnostic specificity of 100% and the sensitivity ranged from 50 to 75%. Combinations of any two peptides improved sensitivity 62.5-87.5% and 100% sensitivity was achieved with three of the four peptides in combination. These data suggest peptides representing diagnostically important Map epitopes could be incorporated into a sensitive diagnostic test.
authors.affiliation: La Trobe University, AdAlta Pty Ltd, 2 Research Drive, VIC 3083, Australia. j.casey@latrobe.edu.au
authors.forename: J L
authors.initials: JL
authors.lastname: Casey
authors.forename: A M
authors.initials: AM
authors.lastname: Sanalla
authors.forename: D
authors.initials: D
authors.lastname: Tamvakis
authors.forename: C
authors.initials: C
authors.lastname: Thalmann
authors.forename: E L
authors.initials: EL
authors.lastname: Carroll
authors.forename: K
authors.initials: K
authors.lastname: Parisi
authors.forename: A M
authors.initials: AM
authors.lastname: Coley
authors.forename: D J
authors.initials: DJ
authors.lastname: Stewart
authors.forename: J A
authors.initials: JA
authors.lastname: Vaughan
authors.forename: W P
authors.initials: WP
authors.lastname: Michalski
authors.forename: R
authors.initials: R
authors.lastname: Luke
authors.forename: M
authors.initials: M
authors.lastname: Foley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D015373:Bacterial Typing Techniques / Q000379:methods*; D015415:Biomarkers / Q000097:blood; D000939:Epitopes; D006041:Goats; D008969:Molecular Sequence Data; D016927:Mycobacterium avium subsp. paratuberculosis / Q000302:isolation & purification / Q000378:metabolism*; D010283:Paratuberculosis / Q000175:diagnosis* / Q000382:microbiology; D019151:Peptide Library; D010455:Peptides / Q000378:metabolism; D011237:Predictive Value of Tests; D011817:Rabbits; D012698:Serologic Tests / Q000379:methods
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; D000939:Epitopes; D019151:Peptide Library; D010455:Peptides