ABSTRACT
A field isolate of Newcastle disease virus (NDV) isolated from northern pintail (Anas acuta) in Tohoku district, northeast Japan, was characterized. Phylogenetic analysis of the fusion protein indicated that the isolate belonged to genotype I and was closely related to isolates from the Far East corresponded to the migration route for this bird species. The isolate had the typical avirulent cleavage site of the fusion protein (112)GKQGR*L(117). In addition, pathogenicity tests indicated the isolate to have avirulent characteristics. However, the isolate has been shown to cause fusion cytopathic effects and form plaques on chicken embryo fibroblasts (CEF) in the absence of trypsin. The present results suggest that the CEF-adapted NDV, which is avirulent, is circulating among waterfowl populations.
Subject(s)
Ducks/virology , Newcastle disease virus/genetics , Amino Acid Sequence , Animals , Cytopathogenic Effect, Viral , Fibroblasts/virology , Newcastle disease virus/pathogenicity , Phylogeny , RNA, Viral/genetics , Viral Fusion Proteins/chemistry , Viral Fusion Proteins/geneticsABSTRACT
Three ostriches (Struthio camelus) were immunized with commercially available live and killed Newcastle disease (ND) vaccines for chickens and the antibody responses to the ND vaccines were evaluated by a virus-neutralization (VN) test. Primary vaccination with the live vaccine, B1, by eye drop was followed with two shots of alum-precipitated killed vaccine via subcutaneous injection in the neck. As a final booster, another live vaccine, Clone 30, was used by eye drop. A VN antibody titer, more than 1:10 was observed for 6 months. This is the first report on the use of a live vaccine by eye drop as a booster in ostriches as well as evaluating responses to ND vaccines using the VN test in this avian species.
Subject(s)
Antibodies, Viral/blood , Newcastle Disease/immunology , Struthioniformes/immunology , Viral Vaccines/immunology , Animals , Chickens , Immunization, Secondary , Newcastle Disease/prevention & control , Ophthalmic Solutions , Viral Vaccines/administration & dosageABSTRACT
Serum samples from 191 ostriches (Struthio camelus) in Japan were tested for antibodies to Newcastle disease virus (NDV) and avian influenza virus (AIV). Twenty-two (12%) contained NDV-specific neutralizing antibodies by a virus-neutralization (VN) test without vaccination. Antibodies to AIV were not detected in the any sera by an agar gel precipitation test. Seven serum samples that had vaccinated with live NDV by eye drop were all positive by the VN test at 1 month post vaccination. A haemagglutination inhibition (HI) test for NDV seemed not to be suitable for ostriches because of non-specific agglutination of chicken red blood cells. No haemagglutinating viruses were isolated. This is the first report on detection of antibodies against NDV in ostriches in Japan.
