Infection of cattle with bovine leukemia virus (BLV) has been observed and reported worldwide, including in Korea. The onsite identification of infected cattle would help decreasing and eradicating BLV infections on farms. Here, we present a new immunochromatographic assay that employs monoclonal antibodies (MAbs) for the detection of antibodies against BLV in the field. BLV envelope glycoprotein (gp)51 was expressed in E. coli, and MAbs against recombinant BLV gp51 were generated for the development of an immunochromatographic assay to detect BLV antibodies in cattle. The sensitivity and specificity of the assay were determined by comparing these results with those obtained from a standard enzyme linked immunosorbent assay (ELISA). A total of 160 bovine sera were used to evaluate the new immunochromatographic assay. Using ELISA as a reference standard, the relative specificity and sensitivity of this assay were determined to be 94.7% and 98%, respectively. Because of its high sensitivity and specificity, this BLV antibody detection assay would be suitable for the onsite identification of BLV infection in the field.
Agriculture ; Animals ; Antibodies* ; Antibodies, Monoclonal ; Cattle ; Deltaretrovirus Antibodies ; Deltaretrovirus Infections ; Enzootic Bovine Leukosis* ; Enzyme-Linked Immunosorbent Assay ; Glycoproteins ; Immunochromatography* ; Korea ; Leukemia Virus, Bovine* ; Sensitivity and Specificity

Porcine reproductive and respiratory syndrome (PRRS) is recognized as one of the most important infectious diseases causing serious economic loss in the swine industry worldwide. Due to its increasing genetic diversity, a rapid and accurate diagnosis is critical for PRRS control. The immunochromatographic strip test (ICST) is a rapid and convenient type of immunoassay. In this study, an on-site immunochromatographic assay-based diagnostic method was developed for detection of PRRS virus (PRRSV)-specific antibodies. The method utilized colloidal gold nanoparticle-labeled dual-type nucleocapsid proteins encoded by open reading frame 7. We evaluated 991 field samples from pig farms and 66 serum samples from experimentally PRRSV-inoculated pigs. Based on true PRRSV-specific antibody-positive or
Agriculture ; Antibodies ; Colloids ; Communicable Diseases ; Diagnosis ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique ; Genetic Variation ; Gold Colloid ; Immunoassay ; Immunochromatography ; Immunoglobulin M ; Methods ; Nucleocapsid Proteins ; Open Reading Frames ; Porcine Reproductive and Respiratory Syndrome ; Porcine respiratory and reproductive syndrome virus ; Sensitivity and Specificity ; Swine