Over the past two decades, enormous advances have occurred in the structural and biological characterization of Newcastle disease virus (NDV). As a result, not only the complete sequence of the viral genome has been fully determined, but also a clearer understanding of the viral proteins and their respective roles in the life cycle has been achieved. This article reviews the progress in the molecular biology of NDV with emphasis on the new technologies. It also identifies the fundamental problems that need to be addressed and attempts to predict some research opportunities in NDV that can be realized in the near future for the diagnosis, prevention and treatment of disease(s).

https://www.tandfonline.com/doi/pdf/10.1080/03079450120078626

Newcastle disease virus: macromolecules and opportunities.

SUMMARY. Newcastle disease (ND) is a major threat to the international poultry industry, causing bird mortality, reduction in growth and egg production, and trade restrictions. The primary strategy available to the poultry industry to control virulent Newcastle disease virus (NDV), the causative agent of ND, is vaccination. LaSota and other commonly used live-virus NDV vaccine strains were developed in the 1950s and 1960s and show a great degree of genetic divergence from currently circulating NDV strains. In order to characterize protective immunity induced by LaSota against a heterologous NDV strain, we vaccinated groups of specific-pathogen-free (SPF) chickens with LaSota (virus titers ranging from 10 2 to 10 8 egg infective dose 50 [EID50 ]i n 10-fold increments) and challenged the birds 14 days later with ZJ1 strain, an NDV strain that was isolated in the year 2000 from geese in China. We monitored multiple parameters of immunity, including serum antibody titers, antigen-specific lymphocyte proliferation, and splenic cytokine expression and determined that SPF birds vaccinated with an adequate titer of LaSota strain live vaccine are fully protected from morbidity and mortality due to challenge with ZJ1 strain NDV, and we concluded that in the absence of interfering maternal antibody, protection due to vaccination increases with vaccine titer until a threshold titer is reached, beyond which, little or no further benefit can be elucidated.

https://bioone.org/journals/avian-diseases/volume-56/issue-3/10043-122011-Reg.1/Characterization-of-Live-LaSota-Vaccine-StrainInduced-Protection-in-Chickens-upon/10.1637/10043-122011-Reg.1.pdf

Characterization of Live LaSota Vaccine Strain–Induced Protection in Chickens upon Early Challenge with a Virulent Newcastle Disease Virus of Heterologous Genotype

Summary A highly reproducible monoclonal antibody (Mab) blocking ELISA (B‐ELISA) has been developed and evaluated for the detection of NDV‐specific antibodies. The Mab utilised is specific for a conserved PMV‐1 serotype‐specific epitope, as demonstrated by the indirect immunoperoxidase test. It reacted with all strains representing different serogroups within the PMV‐1 serotype, but not with any strain belonging to other PMV serotypes. Sensitivity and specificity of the B‐ELISA were compared with the haemagglutina‐tion inhibition test (HI). Blocking and HI antibodies were detected in sera of chickens 8 days post‐experimental infection. The B‐ELISA proved consistently more sensitive than the HI test. In another survey, 62 sera from experimentally vaccinated chickens were tested; 95.2% proved positive by B‐ELISA, 85.5% by indirect ELISA and 74% by HI test. When 504 field sera from vaccinated chickens and turkeys were tested, 98% were positive by B‐ELISA, and 69% by HI. The specificity was evaluated by testi...

https://www.tandfonline.com/doi/pdf/10.1080/03079459608419175

Detection of PMV-1 specific antibodies with a monoclonal antibody blocking enzyme-linked immunosorbent assay.

A novel transcutaneous plasmid-dimethylsulfoxide delivery technique for avian nucleic acid immunization.

A liquid phase blocking ELISA (LPB-ELISA) was adapted for the detection and quantification of antibodies to Newcastle disease virus. Sera from vaccinated and unvaccinated commercial flocks of ostriches (Struthio camelus) and rheas (Rhea americana) were tested. The purified and nonpurified virus used as the antigen and the capture and detector antibodies were prepared and standardized for this purpose. The hemagglutination-inhibition (HI) test was regarded as the reference method. The cutoff point for the LPB-ELISA was determined by a two-graph receiver operating characteristic analysis. The LPB-ELISA titers regressed significantly (P < 0.0001) on the HI titers with a high correlation coefficient (r = 0.875). The two tests showed good agreement (κ = 0.82; P < 0.0001), relative sensitivity (90.91%) and specificity (91.18%), and accuracy (91.02%), suggesting that they are interchangeable.

https://cvi.asm.org/content/cdli/7/6/940.full.pdf

Detection and Quantification of Antibodies to Newcastle Disease Virus in Ostrich and Rhea Sera Using a Liquid Phase Blocking Enzyme-Linked Immunosorbent Assay

Summary Antibody responses of commercial broiler chickens vaccinated for Newcastle disease were assayed by haemagglutination inhibition and enzyme‐linked immunosorbent assay, and the results from the two methods compared. Three‐hundred‐and‐nineteen chickens from 37 farms were assayed. The correlation coefficient was 0.85. Analysis of individual slopes of data from the 37 farms indicated that at least eight chickens from a farm must be sampled to achieve an acceptable degree of parallelism.

Z. Bidin

Papers

Correlation of haemagglutination inhibition and enzyme‐linked immunosorbent assays for antibodies to Newcastle disease virus