Qingmei Li

The authors would like to make the following correction to this published paper

Newcastle disease (ND) is a highly contagious avian disease, causing considerable economic losses to the poultry industry. To obtain a safe, inexpensive, and effective ND vaccine to meet the international trade requirements of differentiating infected from vaccinated animals (DIVA), here we report the production of Oryza sativa recombinant fusion (F) protein in stably transformed transgenic rice seeds via agroinfiltration. The F protein expression level was enhanced 3.6-fold with a genetic background in low glutelin. Inoculation of plant-produced F antigen into Specific Pathogen Free (SPF) chickens markedly elicited neutralizing antibody responses against homologous and heterologous ND virus strains. Two doses of 4.5 μg fully protected chickens from a lethal ND challenge without any clinical symptoms. The mean weight gain of F protein-immunized chickens within 15 days after challenge was significantly higher than that of traditional whole virus vaccine-immunized chickens, thereby obtaining higher economic benefits. Moreover, the sera from the chickens vaccinated with the plant-produced F vaccine did not show reactivity in an immunochromatographic strip targeting the haemagglutinin-neuraminidase protein (HN) protein, and DIVA could be achieved within 10 minutes. Our results demonstrate that the plant-derived F vaccine along with immunochromatographic strips could be useful in the implementation of an NDV eradication program.

We evaluated an immunochromatographic strip for the detection of avian avulavirus 1 (Newcastle disease virus, NDV) based on a high-affinity monoclonal antibody (mAb) that specifically recognizes the hemagglutinin-neuraminidase (HN) protein. The anti-HN mAb was labeled with colloidal gold as the detector. A chicken anti-NDV polyclonal antibody and staphylococcal protein A (SPA) were blotted on the nitrocellulose membrane for the test and control lines, respectively. The strip specifically recognized the NDV antigen with no cross-reactivity to other viruses that were examined. Furthermore, it specifically recognized a variety of NDV isolates, including virulent and attenuated strains. These results were confirmed using hemagglutination (HA) and RT-PCR assays. The NDV detection strip detected 10^4.9 EID₅₀ viruses/0.1 mL in the NDV-infected sample, which is comparable to the classical HA test (10^5.2 EID₅₀/0.1 mL). Following experimental infection, NDV was detected using the detection strip in infected tissues as early as 36 h after experimental infection and prior to development of clinical signs and appearance of gross anatomic lesions. The diagnostic sensitivity and specificity of the NDV detection strip for NDV infection were 83.3% and 100%, respectively, as confirmed by RT-PCR.