title: Detection by immunomagnetic PCR of Mycobacterium avium subsp. paratuberculosis in milk from dairy goats in Norway.
abstract: Milk samples from 340 individual goats in 34 dairy herds throughout Norway were examined for Mycobacterium avium subsp. paratuberculosis (M.a. paratuberculosis) by culture and immunomagnetic separation combined with PCR (IMS-PCR). The samples included three categories; (A) vaccinated dairy goats in herds with paratuberculosis; (B) vaccinated dairy goats in herds with no history of paratuberculosis; (C) unvaccinated goats in herds with no history of paratuberculosis. Viable M.a. paratuberculosis were not detected by culture in any sample, but 24 samples (7.1%) tested positive by IMS-PCR when the PCR products were visualised by dot blot hybridisation. PCR products from five milk samples originating from five different herds were sequenced; all showed 99% homology with the IS900 sequence from M.a. paratuberculosis.M.a. paratuberculosis were detected in all sampled categories. The percentage of IMS-PCR positive samples from herds where paratuberculosis had previously been reported was significantly lower than from herds where the infection had never been diagnosed (3.3 and 9.1%, respectively, P=0.048). Similar proportions of milk samples from vaccinated and non-vaccinated goats tested positive for the presence of M.a. paratuberculosis. Vaccinated goats older than 4 years tested positive more often than vaccinated animals less than 2 years old. Samples collected in May tested significantly more often positive than milk sampled during February-March (13.8 and 2.9%, respectively, P=0.001). This study showed that raw goats' milk in Norway might be contaminated with M.a. paratuberculosis.
authors.affiliation: Department of Bacteriology, National Veterinary Institute, Post Box 8156, N-0033 Oslo, Norway. berit.djonne@vetinst.no
authors.forename: B
authors.initials: B
authors.lastname: Djønne
authors.forename: M R
authors.initials: MR
authors.lastname: Jensen
authors.forename: I R
authors.initials: IR
authors.lastname: Grant
authors.forename: G
authors.initials: G
authors.lastname: Holstad
mesh_terms: D000818:Animals; D001483:Base Sequence; D004251:DNA Transposable Elements / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D005516:Food Microbiology; D015511:Goat Diseases / Q000175:diagnosis / Q000382:microbiology*; D006041:Goats; D018189:Immunomagnetic Separation / Q000662:veterinary; D008892:Milk / Q000382:microbiology*; D008969:Molecular Sequence Data; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics / Q000302:isolation & purification*; D009664:Norway; D010283:Paratuberculosis / Q000175:diagnosis / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012621:Seasons; D017422:Sequence Analysis, DNA; D014611:Vaccination / Q000662:veterinary; D014765:Viral Vaccines / Q000276:immunology / Q000592:standards
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D014765:Viral Vaccines