Showing papers on "Newcastle disease published in 1968"

Influence of animal genotype and age on the amount of circulating interferon induced by newcastle disease virus.

Abstract: Following the paper by Baron & Buckler (1963) describing the release of interferon (Isaacs & Lindenmann, 1957) into the blood of mice injected with viruses, extensive use has been made of this experimental procedure to study various aspects of interferon synthesis in vivo. The usual criterion for selecting animals for such experiments has been to use those within a narrow weight range in random-bred strains. During an investigation on the effect of carcinogens on interferon synthesis in mice (De Maeyer & De Maeyer-Guignard, 1967) we noticed that the amounts of circulating interferon in animals injected with Newcastle disease virus varied with animal age and strain. This observation led to more systematic experiments which are reported here. Mice belonged to three strains. C3H/He and C57Bl mice were purchased from the Laboratory Animal Centre (M.R.C., Carshalton, Surrey, England). Only the first and second generations derived from the Carshalton breeder mice were studied.

Avian influenza A and paramyxo viruses complicating respiratory disease diagnosis in poultry.

Abstract: Prior to 1956, laboratory diagnosticians in the United States could reasonably rely on differentiating and identifying Newcastle disease virus (NDV) as the etiologic agent causing a respiratory infection in chickens or turkeys by demonstrating that the isolate hemagglutinated chicken red blood cells (rbc). Unfortunately, this simple means of differentiation is no longer possible. In other parts of the world, a presumptive diagnosis of Newcastle disease virus by demonstrating hemagglutination of rbc's with infectious fluids of embryos has been complicated by the presence of Fowl Plague, a disease which preceded Newcastle disease as a poultry pathogen. In 1949, Dinter isolated a hemagglutinating virus from chickens in Germany, identified as virus "N," which produced a pneumoencephalitis-like disease in young chicks. This agent was found to be an antigenic variant of the fowl plague virus (8,9). Other agents that hemagglutinate chicken rbc were recovered not only from poultry but also from swine and horses (2,14,15,23). These agents belong to the myxovirus group. More specifically, all except NDV and strain yucaipa of the paramyxovirus group show some cross-antigenic relationship with the complement-fixating soluble nucleic acid component (G) of type A (PR8) influenza virus (1,2).

Bovine diarrhea virus. II. END phenomenon: exaltation of Newcastle disease virus in bovine cells infected with bovine diarrhea virus.

Abstract: Virus strain No. 12, one of the new isolates from Japanese cattle described previously, was studied for its physicochemical properties. The new isolate was shown to be very small in size by centrifugation and filtration, being filtrable through Millipore filters of 50 mμ pore size. It appears to be an RNA virus as its replication was not inhibited by 5-iodo-2′-deoxyuridine. The virus was readily inactivated by ether and deoxycholate, and partially by trypsin; was labile at pH 3, not stabilized by 1 m MgCl2 at 50 C, was inactivated by ultraviolet, and withstood repeated freeze-thawing. Further it was readily inactivated at 56 C but more slowly at 37 C, and was stable at lower temperatures. These findings support the identification of the isolated virus as the bovine diarrhea (BD) virus. The properties of BD virus, i.e. size, type of nucleic acid, ether, chloroform and deoxycholate sensitivities, and acid lability, appear to be similar to those of arboviruses. The trypsin sensitivity of BD virus is similar to the B group of arboviruses, which, unlike the A group, sensitive to trypsin. For the classification of BD virus as well as hog cholera virus, which is closely related, further elucidation of properties, fine structure of the virion, etc., is needed.

Differentiation of representative Newcastle disease virus strains by their plaque-forming ability on monolayers of chick embryo fibroblasts.

Abstract: The 125 isolates of Newcastle disease virus in the Repository at the University of Wisconsin have been recovered from several species of animals and from many countries over the past three decades. This collection provided an opportunity to study the usefulness of plaque morphology as a means of strain identification and to establish the extent to which these isolates were internally heterogeneous. The plaque morphology of 41 NDV strains was examined.

Vaccination of Congenitally-Immune Chicks against Newcastle Disease Virus

Abstract: SummaryOne to 2-day-old chicks with different levels of passive immunity and controls were vaccinated with an homogenate of chemically-inactivated Newcastle disease virus antigen-antibody complexes, excess antibody, and aluminum hydroxide adjuvant. The antigen-antibody complex vaccine protected 65% or more of the chicks (usually < 80%) against a challenge dose of 104.5 BLD50 for at least 10-weeks postvaccination. Comparable protection was not achieved in the passively-immune chicks when vaccinated with preparations containing only antigen and adjuvant. In susceptible chicks, however, the antigen-antibody complex vaccine did not confer any better protection against challenge inoculation than did simple vaccines. It was concluded that immunological refractoriness of congenitally-immune chicks can be surmounted by appropriate vaccination with an antigen-antibody complex vaccine.

An interference type of serological test for infectious bronchitis virus using Newcastle disease virus.

Abstract: Antibodies against infectious bronchitis virus (IBV) have generally been identified and measured by injecting serum-virus mixtures into embryonating chicken eggs. The serum samples may be tested against an embryo-lethal strain such as Beaudette (Michigan State University Repository, IBV 42) so that final evaluation of the virus-neutralizing activity may be made 72 hr after inoculation of the eggs. The Beaudette strain is representative of the Massachusetts serological group and is antigenically dissimilar from many known IBV strains (1). This difference in antigenic composition can result in undetected or poorly quantitated levels of antibodies directed against other IBV strains. When IBV strains that are not egg-lethal are used for more critical serological evaluations than can be obtained with the Beaudette strain, embryos are examined 9 to 10 days after inoculation of the eggs for signs of IBV infection such as stunting, clubbed feathers, and curled toes. The test is a lengthy, tedious, and subjective process. This report describes adaptation of the infectious bronchitis virus-Newcastle disease virus (IBV-N!DV) interference test in cell cultures (2) for measuring and identifying antibodies against several strains of IBV which are not consistently egg-lethal or cytopathogenic for cell cultures.

A plaque assay for duck plague virus.

Abstract: A plaque assay for duck plague virus was developed for a chicken embryo-adapted virus and a duck lethal virus and used to determine the identity of these viruses. Using the plaque inhibition neutralization test, duck plague virus was differentiated from Newcastle disease, fowl plague, and duck hepatitis viruses. The plaque morphology is described.

Relation of interferon synthesis to abortive replication of Newcastle disease virus in L cells.

Abstract: Infection of L cells with Newcastle disease virus (NDV) results in abortive replication, with the production of very few plaque-forming units (PFU) of virus per cell (W. C. Wilcox, Virology 9:30, 1959; K. Paucker et al., Virology 17:301, 1962). It is known that interferon is synthesized by L cells infected with NDV, and the possibility exists that this endogenously produced inhibitor may be responsible for the abortive replication (W. Henle et al., J. Exptl. Med. 110:525, 1959; J. E. Rodriguez et al., J. Virol. 1:1, 1967). With certain ribonucleic acid (RNA) viruses, enhanced viral replication accompanies the inhibition by actinomycin D of interferon synthesis (E. Heller, Virology 21:652, 1963; R. R. Wagner, Trans. Assoc. Am. Physicians 76:92, 1963). In the present study, the influence of actinomycin D on the synthesis of interferon and on the replication of NDV in L cells was tested. Descriptions of the viruses, cell cultures, and methods used for production and assay of interferon have been given elsewhere (J. S. Youngner et al., J. Bacteriol. 92:862, 1966). Actinomycin D was made available through the courtesy of H. B. Woodruff of Merck, Sharp and Dohme. The influence of suppression of interferon production on the replication of NDV was tested in the following manner. L-cell cultures were treated with different concentrations of actinomycin D and then infected with NDV. The effects of the antibiotic on cellular RNA synthesis (3H-uridine incorporation), interferon production, and virus replication are summarized in Fig. 1. As little as 0.01 ,ug of actinomycin D per ml produced a 23% reduction in labeled uridine incorporation and a 50% reduction in interferon titer. At 0.5 ug of actinomycin D per ml, 3H-uridine incorporation was only 8% of that of the control, and no interferon was detectable in the fluids removed from such cultures after infection with NDV. In contrast, NDV replication was not significantly different in control cultures and in cultures treated with up to 0.1 Mug of actinomycin D per ml. Higher concentrations of antibiotic produced a reduction in virus yield which could be explained, at least in part, by a drop in viability of the cells after 24 hr of exposure to the antibiotic. From the results described in Fig. 1, it was concluded that there was no relationship between interferon production and abortive replication of NDV in L-cell cultures, since inhibition of interferon synthesis by actinomycin D in cells infected with NDV did not enhance the yield of infective virus. The possibility existed that undetected or cell-associated interferon, or inhibitors distinct from interferon, were responsible for the low yield of infective NDV. In an attempt to eliminate this possibility, the ability of a superinfecting virus (Semliki Forest virus-SFV) to replicate was tested in cells in which interferon production was suppressed. This experiment was carried out as follows. Cultures of L cells in 2-oz (56 ml) bottles were divided into four groups. Groups 1 and 3 were treated with actinomycin D (0.5 ug/ml) in the usual manner; i.e., antibiotic was present in all fluids until superinfection with SFV; groups 2 and 4 did not receive the antibiotic. After 1 hr at 37 C, groups 1 and 2 were infected with NDV at an input multiplicity of 5; groups 3 and 4 were not infected with NDV. After 24 hr at 37 C, fluids from each group of cultures were withdrawn and were tested for interferon activity. The cells were challenged with SFV (multiplicity of infection = 8) and incubated for an additional 20 hr at 37 C, after which the fluids from these cultures were harvested and tested for SFV infectivity. The results presented in Table 1 show that, when interferon was produced in response to NDV (group 2), SFV replication was effectively suppressed. In contrast, when interferon production was inhibited by actinomycin D (group 1), SFV replication was almost equal to that obtained in the two control groups (groups 3 and 4) in which cells were not exposed to NDV. The difference in the SFV replication

Comparative immunogenicity of three strains of newcastle disease virus used in inactivated vaccines

Abstract: The degree of immunity induced in chickens by inactivated Newcastle disease vaccine depends on the strain of virus, the inactivating agent, the adjuvant, and host factors such as age and the presence or absence of passive antibodies (1). Hanson et al. (3) compared the immunogenicity of 5 strains of Newcastle disease virus (NDV) in formalinized vaccines. They concluded that certain strains were much better immunogens than others, but that there was no relationship between immunogenicity and virulence or heat stability of the strain. Sullivan et al. (6), using beta-propiolactone (BPL) as the

Growth inhibition of Newcastle disease virus upon superinfection of poliovirus in the presence of guanidine.

Abstract: When HeLa cells were simultaneously infected with a high multiplicity of poliovirus and a low multiplicity of Newcastle disease virus (NDV), a definite inhibition of NDV growth was observed, while the growth of poliovirus was unaffected. Moreover, under conditions where the multiplication of poliovirus was prevented by guanidine, which is known to inhibit the formation of the ribonucleic acid (RNA)-dependent RNA polym-

Absence of Nucleotide Sequence Complementarity between Sindbis Virus and Newcastle Disease Virus Genomes

Abstract: SummaryThe RNA isolated from Sindbis virus was annealed with RNA isoated from Newcastle disease virus (NDV). No ribonuclease-resistant hybrid was formed, indicating that these viral RNA's do not have complementary nucleotide sequences, despite complementary base compositions.

Antibodies for Newcastle disease virus and Mycoplasma gallisepticum in sera from domestic chickens and game fowl of Kenya.

Abstract: Studies by one of the authors (2) present serological evidence for infection with a member or members of the group A (1) sarcoma-leukosis viruses in Kenya which indicate that they maintain themselves as endemic infections under natural conditions in a variety of game fowl as well as chickens running free in local villages in remote areas of the African bush country. Representative sera of those collected were examined for the presence of antibodies to Newcastle Disease virus (NDV) and Mycoplcsma gallisepticum (MG), using the hemagglutination-inhibition test for NDV and the agglutination test for MG in order to establish the infection with these agents in the areas studied.