Commercial ELISA kits are commonly used to assess the levels of chicken antibodies against NewCastle Disease Virus (NDV) and trace a field strain infection. Nevertheless, the specificity of these kits vis-à-vis e...Commercial ELISA kits are commonly used to assess the levels of chicken antibodies against NewCastle Disease Virus (NDV) and trace a field strain infection. Nevertheless, the specificity of these kits vis-à-vis endemic strains in Lebanon remains in question. This study developed an in-house indirect ELISA system to evaluate the level of chicken antibodies against a predominant velogenic NDV strain belonging to Genotype VI. A checkerboard analysis comprised a five-factorial multivariate experiment to optimize the protocol: coating antigen concentration, blocking buffer utilization, serum and conjugate dilution levels, and OD reading wavelength. The developed test was optimized and then validated through parallel testing of the sera of 20 broilers and 5 layers using standard serological assays. There was a strong correlation between the developed ELISA results and those obtained with the Hemagglutination Inhibition test (P < 0.01), and a commercial NDV ELISA kit (P < 0.05). The specificity, sensitivity, and reproducibility of the developed ELISA suggest that it can be used as the test of choice for the assessment of chicken antibody titers against locally circulating velogenic NDV strains, specifically those belonging to Genotype VI. It also offers better help in the serological detection of birds’ exposure to the said strains.展开更多
文摘Commercial ELISA kits are commonly used to assess the levels of chicken antibodies against NewCastle Disease Virus (NDV) and trace a field strain infection. Nevertheless, the specificity of these kits vis-à-vis endemic strains in Lebanon remains in question. This study developed an in-house indirect ELISA system to evaluate the level of chicken antibodies against a predominant velogenic NDV strain belonging to Genotype VI. A checkerboard analysis comprised a five-factorial multivariate experiment to optimize the protocol: coating antigen concentration, blocking buffer utilization, serum and conjugate dilution levels, and OD reading wavelength. The developed test was optimized and then validated through parallel testing of the sera of 20 broilers and 5 layers using standard serological assays. There was a strong correlation between the developed ELISA results and those obtained with the Hemagglutination Inhibition test (P < 0.01), and a commercial NDV ELISA kit (P < 0.05). The specificity, sensitivity, and reproducibility of the developed ELISA suggest that it can be used as the test of choice for the assessment of chicken antibody titers against locally circulating velogenic NDV strains, specifically those belonging to Genotype VI. It also offers better help in the serological detection of birds’ exposure to the said strains.
