title: Removal of Lipid from Serum Increases Coherence between Brucellosis Rapid Agglutination Test and Enzyme-linked Immunosorbent Assay in Bears in Alaska, USA.
abstract: In cases of chronic Brucella spp. infection, results of the rose bengal plate test (RBPT) and indirect enzyme-linked immunosorbent assay (ELISA) should be coherent, as reported in controlled conditions in the literature. We compared RBPT and ELISA results in 58 Alaska grizzly bears ( Ursus arctos horribilis), eight Kodiak brown bears ( Ursus arctos middendorffi), and six Alaska Peninsula brown bears ( Ursus arctos gyas). Of the 72 bears tested, 42 (58%) were ELISA positive and 53 (73%) were RBPT positive. However, the coherence between the tests was only fair (K=0.37, SE=0.11), suggesting that either the serologic results were not compatible with Brucella spp. infection or that there was a technical problem with the tests. To address a potential technical problem, we performed a 30-min chloroform/centrifugation cleanup. Following cleanup, the ELISA identified 43 positives (59%) and the RBPT identified 47 (65%), and the coherence between the tests was much improved (K=0.80, SE=0.07). We recommend cleaning wildlife sera with a high lipid content before performing RBPT and performing RBPT and ELISA in parallel to assess coherence. Our results suggest that Alaskan brown bears have been exposed to Brucella spp.
authors.affiliation: 1 UiT - The Arctic University of Norway, Arctic Infection Biology, Postboks 6050 Langnes, N-9010 Tromsø, Norway.
authors.forename: Jacques
authors.initials: J
authors.lastname: Godfroid
authors.affiliation: 2 Alaska Department of Fish and Game, 1300 College Road, Fairbanks, Alaska 99701-1551, USA.
authors.forename: Kimberlee
authors.initials: K
authors.lastname: Beckmen
authors.affiliation: 1 UiT - The Arctic University of Norway, Arctic Infection Biology, Postboks 6050 Langnes, N-9010 Tromsø, Norway.
authors.forename: Ingebjørg
authors.initials: I
authors.lastname: Helena Nymo
mesh_terms: D000372:Agglutination Tests; D000413:Alaska; D000818:Animals; D000907:Antibodies, Bacterial; D002002:Brucella / Q000276:immunology; D002006:Brucellosis / Q000175:diagnosis* / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay; D008055:Lipids; D001503:Ursidae / Q000382:microbiology*
chemical_list: D000907:Antibodies, Bacterial; D008055:Lipids
keywords: Alaska Peninsula brown bear; Alaska grizzly bear; Brucella spp.; Kodiak brown bear; bear; brucellosis; lipemic serum; serum cleanup