The bovine enterovirus (BEV) is a pathogen found the digestive tracts of cattle. Recently, the BEV was discovered in cattle in a province in China. A rapid and effective detection method for the BEV is essential. An assay was carried out using two specific primers designed to amplify a highly conserved sequence of the 3D gene. A recombinant plasmid containing the target gene 3D was constructed as a standard control. The limit of detection of the reaction was 7.13 x 10(1) plasmid copies/μL of initial templates, which was tenfold more sensitive than the conventional reverse-transcription-polymerase chain reaction (RT-PCR). Moreover, the assay was highly specific because all negative controls and other viruses of clinical relevance did not develop positive results. Assay performance on field samples was evaluated on 44 (41 diarrhea and 3 aerosol) samples and compared with the conventional RT-PCR assay. Sixteen diarrhea samples were positive (16/41, 39. 02%) and 3 aerosol samples were positive (3/3, 100%). Preliminary results for clinical detection showed that the SYBR Green I real-time PCR assay was highly sensitive, specific and reproducible. The robustness and high-throughput performance of the developed assay make it a powerful tool in diagnostic applications for epidemics and in BEV research.
Animals ; Cattle ; Cattle Diseases ; diagnosis ; virology ; DNA Primers ; chemistry ; genetics ; Enterovirus Infections ; diagnosis ; veterinary ; virology ; Enterovirus, Bovine ; genetics ; isolation & purification ; Organic Chemicals ; chemistry ; Real-Time Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

Objective:To prepare anti-human IgE nanobody by phage display technology,and to establish a method for hyper-sensitivity detection of cat dander specific IgE antibody.Methods:Allergen bio-information of cat was searched in WHO/IUIS Allergen Database.After synthesizing sequence,recombinant cat dander allergenic protein Fel d 1 was expressed and purified in prokaryotic ex-pression system.Human IgE was used to immunize Bactrian camel and RNA were extracted from lymphocyte to construct phage dis-play library.Library capacity,diversity and insertion rate were analyzed,anti-human IgE nanobody were obtained by screening and identification.A magnetic particle chemical method for cat dander specific IgE antibody detection was established using recombinant allergen-coupled magnetic particles and acridine ester-labeled nanobodies.Results:Capacity of phage display library was 1.88×108 cfu/ml,insertion rate was 93.6%,and purity of nanobody was>95%.Linear range of the method based on nanobody was 0.1～100 U/ml,who was consistent with ImmunoCAP detection system by clinical data.Conclusion:Nanobody-based cat dander specific IgE antibody hypersensitivity assay is successfully prepared,providing a technical basis for auxiliary diagnosis of cat allergic diseases.