Faecal shedding detected earlier than immune responses in goats naturally infected with Mycobacterium avium subsp. paratuberculosis.
Paratuberculosis was diagnosed in a goat herd that participated in a sanitation program against Mycobacterium avium subsp. paratuberculosis. The aim of this study was to characterise the development of gamma interferon (IFN-γ) and antibody responses as well as the occurrence of faecal shedding. Faecal culture appeared surprisingly sensitive as about 18% and 40% of the goats were positive at 9 and 15-17 months of age, respectively, and shedding was often seen prior to peripheral immune responses. Peripheral IFN-γ responses were not related to protection as clinical and high shedding goats often had high responses. An IFN-γ response usually preceded a humoral response. However, positive antibody titers could sometimes be seen simultaneously with, and even prior to, IFN-γ responses. In conclusion, faecal culture appeared as sensitive as IFN-γ testing. Furthermore, the antibody ELISA and the IFN-γ assay may perform equally well in an infected herd if surveillance is conducted annually.
Lybeck
Kari R
KR
Department of Animal Health, National Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway. Electronic address: kari.lybeck@vetinst.no.
Storset
Anne K
AK
Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, P.O. Box 8146, Dep., N-0033 Oslo, Norway.
Djønne
Berit
B
Department of Animal Health, National Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
Valheim
Mette
M
Department of Animal Health, National Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
Olsen
Ingrid
I
Department of Animal Health, National Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D057138:Bacterial Shedding; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005243:Feces / Q000382:microbiology*; D015511:Goat Diseases / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D006041:Goats; D007371:Interferon-gamma / Q000097:blood; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology / Q000302:isolation & purification*; D010283:Paratuberculosis / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D015203:Reproducibility of Results
D000907:Antibodies, Bacterial; D007371:Interferon-gamma