Wyoming Game and Fish Department, Wildlife Health Laboratory, 1174 Snowy Range Road, Laramie, Wyoming 82070, USA.
University of Wyoming, Department of Mathematics and Statistics, 1000 E University Avenue, Laramie, Wyoming 82071, USA.
J Wildl Dis. 2021 Apr 1;57(2):386-392. doi: 10.7589/JWD-D-20-00021.
We evaluated hemolyzed, bacterially contaminated, and Nobuto filter paper-derived serum, collected from 50 Rocky Mountain elk (Cervus elaphus nelson) in 2017 and 2019, divided into eight treatments to determine antibody retention. Serum was analyzed on Brucella abortus-specific fluorescence polarization assay utilizing plates and tubes. Reference titers and serostatus were compared to serum held at 22 C for 4, 8, 12, and 16 d; frozen clotted blood; blood with 2% and 10% elk rumen content (held for 8 d at 22 C); and serum eluted from Nobuto filter paper. Using Cohen's kappa test of agreement, plate assay serostatus agreement was substantial or outstanding in all treatments. Serostatus agreement was outstanding in all treatments utilizing tubes. The mean change in score (treatment minus reference) showed significant negative bias in serosuspect or seropositive animals in the frozen, 2% rumen, and 10% rumen treatments on the plate assay, and the day 16 and 10% rumen treatments on the tube assay, that could ultimately result in an animal being misclassified into a serosuspect or seronegative category. Serum eluted from Nobuto filter paper produced inconsistent results and is not recommended as an alternative to serum derived from blood. Although the potential for misclassification of animals with low titers exists, analyzing hemolyzed and bacterially contaminated serum from Brucella abortus nonendemic areas can increase sample size and the potential to detect seropositive animals.
我们评估了 2017 年和 2019 年从 50 头落基山麋鹿（Cervus elaphus nelson）收集的溶血、细菌污染和 Nobuto 滤纸衍生血清，将血清分为 8 种处理方式，以确定抗体保留情况。血清利用平板和试管进行布鲁氏菌特异性荧光偏振检测分析。参考滴度和血清学状态与在 22°C 下保存 4、8、12 和 16 天的血清、冷冻凝固的血液、含有 2%和 10%麋鹿瘤胃液（在 22°C 下保存 8 天）以及从 Nobuto 滤纸洗脱的血清进行比较。使用 Cohen 的一致性 Kappa 检验，平板检测的血清学状态在所有处理中均具有显著或极好的一致性。使用试管的所有处理的血清学状态均具有极好的一致性。在平板检测中，冷冻、2%瘤胃和 10%瘤胃处理中血清可疑或阳性动物的评分（处理与参考）的平均变化呈显著负偏倚，而在试管检测中，16 天和 10%瘤胃处理的评分（处理与参考）的平均变化呈显著负偏倚，这可能最终导致动物被错误分类为血清可疑或血清阴性类别。从 Nobuto 滤纸洗脱的血清产生了不一致的结果，不建议将其作为血清的替代物。尽管存在对低滴度动物进行错误分类的可能性，但分析来自布鲁氏菌非流行地区的溶血和细菌污染血清可以增加样本量，并增加检测血清阳性动物的可能性。
