Ramírez-Pfeiffer C, Díaz-Aparicio E, Rodríguez-Padilla C, Morales-Loredo A, Alvarez-Ojeda G, Gomez-Flores R
Instituto Nacional de Investigaciones Forestales y Agropecuarias, Campo Experimental Río Bravo, Río Bravo, Tamaulipas, Mexico.
Vet Immunol Immunopathol. 2008 Jun 15;123(3-4):223-9. doi: 10.1016/j.vetimm.2008.02.001. Epub 2008 Feb 16.
The current method for goat brucellosis diagnosis is based on the World Organization for Animal Health (OIE) using the screening card test (CT), with antigen at 8% (CT8) or 3% (CT3) of cell concentrations, and the confirmatory complement fixation test (CFT). However, these tests do not differentiate antibodies induced by vaccination from those derived from field infections by Brucella species or other bacterial agents; in places like Mexico, where the prevalence of brucellosis and the vaccination rates are high, there is a considerable percentage of false positive reactions that causes significant unnecessary slaughter of animals. Furthermore, results of the fluorescence polarization assay (FPA) using the Brucella abortus O-polysaccharide (OPS) tracer in goats are poorer than those with cattle. The present study was undertaken to investigate a tracer prepared from the native hapten (NH) of the Rev. 1 strain of Brucella melitensis to improve FPA performance on goat brucellosis diagnosis. Evaluation of 48 positive samples and 96 negative samples showed that the NH tracer was more accurate (p<0.01) than the OPS tracer (97.2% vs. 93.8% accuracy, respectively). On the diagnostic performance evaluation, the NH tracer performed better (87.5% accuracy, 79.5% sensitivity, 84.3% specificity, and 163.8 performance index) than the OPS tracer (83.5%, 75.9%, 81.0%, and 156.9, respectively) using 1009 positive and 2039 negative Mexican field goat sera samples selected by test series approved by the OIE (card test 3% and CFT). We demonstrated a new application for the NH lipopolysaccharide on detecting antibodies against Brucella using the FPA, which may yield faster results (minutes vs. 24-72h) than the immunodiagnosis assays frequently used in bovine brucellosis. In addition, NH tracer produces similar or better performance results than the conventional OPS tracer, using the FPA in goat sera samples.
目前山羊布鲁氏菌病的诊断方法是基于世界动物卫生组织（OIE）的筛查卡试验（CT），抗原细胞浓度为8%（CT8）或3%（CT3），以及确证性补体结合试验（CFT）。然而，这些试验无法区分由疫苗诱导产生的抗体与布鲁氏菌属或其他细菌病原体引起的野外感染所产生的抗体；在墨西哥等地，布鲁氏菌病患病率和疫苗接种率都很高，存在相当比例的假阳性反应，导致大量动物被不必要地屠宰。此外，在山羊中使用流产布鲁氏菌O-多糖（OPS）示踪剂的荧光偏振测定（FPA）结果比在牛中要差。本研究旨在研究一种由羊种布鲁氏菌Rev. 1菌株的天然半抗原（NH）制备的示踪剂，以提高FPA在山羊布鲁氏菌病诊断中的性能。对48份阳性样本和96份阴性样本的评估表明，NH示踪剂比OPS示踪剂更准确（p<0.01）（准确率分别为97.2%和93.8%）。在诊断性能评估中，使用经OIE批准的试验系列（3%卡试验和CFT）选择的1009份墨西哥野外山羊阳性血清样本和2039份阴性血清样本，NH示踪剂的表现优于OPS示踪剂（准确率分别为87.5%、79.5%、84.3%和表现指数163.8）（分别为83.5%、75.9%、81.0%和156.9）。我们展示了NH脂多糖在使用FPA检测抗布鲁氏菌抗体方面的新应用，与牛布鲁氏菌病常用的免疫诊断试验相比，它可能产生更快的结果（几分钟与24 - 72小时）。此外，在山羊血清样本中使用FPA时，NH示踪剂产生的性能结果与传统OPS示踪剂相似或更好。
