[show abstract][hide abstract] ABSTRACT: A latex agglutination test (LAT) for detecting antibody against Bluetongue virus (BTV) in ruminants was developed using latex beads coupled with recombinant VP7 protein. Compared with competitive enzyme-linked immunosorbent assay (ELISA), the specificity and sensitivity of the LAT were 99.0% and 93.0%, respectively. There was excellent agreement between the results obtained by competitive ELISA and the LAT (kappa = 0.930). Because it is rapid and easy to use, the LAT could be used for BTV antibody detection, especially for screening many serum samples.
Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 03/2010; 22(2):242-4. · 1.18 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this study, an immunochromatographic strip (ICS) was developed for the detection of bluetongue virus (BTV) serum antibodies. Colloidal gold particles labeled with streptococcal protein G (SPG), which can bind to the F(C) fragment of mammalian immunoglobulins, were used as the detector reagent. A recombinant VP7 BTV protein and a purified rabbit anti-SPG antibody were immobilized on test and control regions of a nitrocellulose membrane, respectively. In order to evaluate the ICS, 37 sera from animals exposed to different BTV serotypes were used as positive controls. In addition, 50 positive sera against viruses other than BTV, and eight sera taken from naive healthy sheep were used to determine the specificity of the ICS. Three hundred and three field sera taken from sheep and cattle were used after the above sera had been used for validation. Compared with the competitive ELISA (c-ELISA), the specificity and sensitivity of the ICS was 97.6% and 100%, respectively. There was excellent agreement between the results obtained by c-ELISA and the ICS (kappa=0.930). As it is rapid and easy to use, the test is suitable for the serological surveillance of BTV infection in the field.
Journal of virological methods 10/2009; 163(1):68-73. · 2.13 Impact Factor
[show abstract][hide abstract] ABSTRACT: The apxIIC gene of Actinobacillus pleuropneumoniae serotype 7 was inactivated by homologous recombination using a sucrose counter-selectable marker system, resulting in a mutant strain that had no antibiotic resistance marker and expressed an inactivated ApxII toxin. The safety and immunogenicity of the mutant were evaluated in mice. The mutant strain caused no adverse effects in mice at doses up to 2 x 10(9) CFU via the intraperitoneal route while the parental strain induced total mortality at a dose of 2 x 10(7) CFU. Mice vaccinated intraperitoneally with the mutant strain had 100% and 70% protection against homologous (serotype 7) or heterologous (serotype 1, 3) challenge with A. pleuropneumoniae, respectively. The A. pleuropneumoniae mutant strain HB04C- and the counterselection method used in the study show promise in developing effective live vaccines for porcine pleuropneumonia and for other infections diseases of the respiratory system.