Showing papers on "Newcastle disease published in 1984"

An enzyme-linked immunosorbent assay that measures protective antibody levels to Newcastle disease virus in chickens.

Abstract: SUMMARY An enzyme-linked immunosorbent assay (ELISA) was developed to measure antibodies to Newcastle disease virus (NDV) in chickens. Chickens 6 to 33 weeks old, with a variety of vaccination histories, were bled before challenge with a velogenic strain of NDV. Fourteen days post-challenge, 63 of the 73 challenged birds had survived. ELISA results of pre-challenge sera corresponded directly with survival rates of birds challenged with NDV. RESUMEN

Use of egg yolk in serological tests (ELISA and HI) to detect antibody to Newcastle disease, infectious bronchitis, and Mycoplasma gallisepticum.

Abstract: Serum and yolks from commercial flocks and from hens exposed to Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and Mycoplasma gallisepticum (MG) were tested for immunoglobulin G antibody by the enzyme-linked immunosorbent assay (ELISA) and the hemagglutination-inhibition (HI) test. Yolks prepared by chloroform extraction and low-speed centrifugation performed well in the serological tests used and were a suitable alternative to serum for antibody determination by the ELISA for NDV, IBV, and MG and by HI test for NDV.

Comparison of the immunogenicity of Newcastle disease virus strains V4, Hitchner B1 and La Sota in chickens. 2. Tests in chickens with maternal antibody to the virus.

Abstract: The immunogenicity of three Newcastle disease virus (NDV) strains--V4, Hitchner B1 and La Sota, was assessed in chickens that had varying levels of maternal antibody to the virus. Chickens were immunised at different ages by the eye drop and aerosol methods. The immune response of chickens to similar doses of the strains was affected by the presence of maternal antibody. Both the level of maternal antibody and the strain of virus used affected the result. Strain La Sota was least affected as it took higher levels of maternal antibody to depress response to it than were required to have a similar effect on Hitchner B1 and V4. Strain V4 was the strain most affected by circulating maternal antibody. The results demonstrated that strain V4 was less immunogenic than Hitchner B1 and La Sota when used in chickens with maternal antibody to NDV.

Comparison of the immunogenicity of Newcastle disease virus strains V4, B1 and La Sota in chickens

Abstract: The immunogenicity of the Australian Newcastle disease virus (NDV) strain V4 was compared with that of the International reference preparation of Hitchner B1 and a commercial La Sota strain. Immunity was assessed serologically using the log mean HI titres 21 days after immunisation, the percentage of birds in each group which developed titres greater than 2(3) and their resistance to graded challenge doses of the virulent Herts 33/56 strain of NDV. These tests showed that the V4 strain was significantly less immunogenic (P less than 0.01) than the B1 or La Sota strains when administered intraocularly (eye drop) or by aerosol methods. When given in the drinking water V4 induced a better immunity (P less than 0.01) than the B1 strain in one of 2 experiments.

Newcastle disease virus: the effect of monoclonal antibody in the overlay on virus penetration and the immunoselection of variants.

Abstract: Monoclonal antibody to the haemagglutinin-neuraminidase or the fusion glycoprotein of Newcastle disease virus blocked virus penetration which otherwise occurred within 90 s of the temperature being increased from 4 degrees C to 37 degrees C. These antibodies regularly immunoselected variant plaques only when incorporated into the agarose overlay. Variant viruses then formed plaques whereas the growth of non-neutralized normal virus was suppressed.

Atypical disease produced in chickens by Newcastle disease virus isolated from exotic birds.

Abstract: Chickens were infected with a Newcastle disease virus (NDV) recovered from exotic birds with severe clinical disease and with lesions characteristic of viscerotropic velogenic Newcastle disease (VVND). The infection in chickens was inconsistently lethal, some infected chickens were not clinically affected, and gastrointestinal involvement was only marginally evident. Pathogenicity of the virus for chickens was not detectably altered by laboratory passage in chickens or by limit dilution passage in chicken embryos. The results suggest that the difference between velogenic NDV pathotypes may not always be distinct and that clinical manifestations of VVND in chickens may not always be predictable based on signs and lesions observed in exotic birds.

Biological functions of monospecific antibodies to envelope glycoproteins of Newcastle disease virus.

Abstract: Monospecific antisera to HN and F glycoproteins of Newcastle disease virus were prepared, and their effects on the biological activities of the virus were investigated. Anti-HN serum inhibited hemagglutinating and neuraminidase activity, as well as hemolysis. Anti-F serum had no effect on hemagglutination or neuraminidase but inhibited hemolysis and virus-induced cell fusion.

Duration of excretion of virulent Newcastle disease virus following challenge of chickens with different titres of serum antibody to the virus.

Abstract: Virulent Newcastle disease virus (NDV) was isolated from susceptible and immune chickens following intra-ocular challenge with the Essex '70 strain. Challenge virus was isolated from the trachea and cloaca of susceptible birds until they died 7 to 9 days after challenge. This virus was isolated from immunised chickens for up to 14 days after challenge. The duration of excretion was influenced by the prechallenge serum antibody titre to NDV. It persisted longest in chickens with titres of 2(3) to 2(7) and decreased in length and frequency from chickens with titres in the range 2(8) to 2(12). Chickens with pre-challenge titres of 2(3) to 2(5) developed 2- to 3- fold increases in post-challenge titres, whereas those with higher pre-challenge titres had smaller proportional increases in titre. Excretion of virulent virus from immunised birds should be considered in the development of Newcastle disease control programs.

A regular subunit pattern seen on non-infectious Newcastle disease virus particles.

Abstract: A pseudo-crystalline array of subunits has been observed on particles of the La Sota, in contrast to the Ulster , strain of Newcastle disease virus (NDV) grown in MDBK tissue culture without trypsin. This regular arrangement of subunits was associated with the semi-permissive nature of the tissue culture system, as it disappeared when trypsin, which allows infectious virus to be made, was added. The phenomenon described was considered to be related to the crystalline array of matrix protein which has been described inside the envelope of Sendai virus and NDV by others.

Isolation of influenza A virus and paramyxoviruses from sentinel domestic ducks.

Abstract: One strain of influenza A virus ( H4N6 ), three strains of Newcastle disease virus (NDV) and one strain of paramyxovirus (PMV) type 4 were isolated from tracheal and cloacal swabs of sentinel domestic ducks by inoculation of tested samples into the amniotic and allantoic cavities of chick embryos (CE).

A survey of disease in five commercial flocks of meat breeder chickens.

Abstract: SUMMARY Causes of sickness and death in approximately 30,000 chickens in 5 meat breeder flocks were investigated between May 1979 and April 1980. Approximately 23% of disease was due to neoplasms; 81% of these were Marek's disease despite vaccination against this infection. Other frequent diagnoses included cellulitis (15%), respiratory disease (14%), lesions of the reproductive tract (11%) and tenosynovitis/arthritis (9%). Antibodies to Mycoplasma gallisepticium, avian adenovirus, infectious bursal disease virus and reticuloendotheliosis virus were present in all flocks. Antibody to Newcastle disease virus (NDV) was found in 2 flocks but titres were not considered protective against a virulent NDV challenge. Antibody to egg drop syndrome 1976 virus was found in 2 flocks comprised of the same breed of bird.

Further Studies on the Immunization of Chickens with Temperature-Sensitive Mycoplasma gallisepticum Mutant

Abstract: Newly hatched chickens were immunized with a temperature-sensitive (TS) Mycoplasma gallisepticum (MG) mutant (TS 100). Immunized chickens resisted challenge with the virulent S6 strain. The dose of TS MG needed for protection was less than 3.3 X 10(4) colony-forming units. After immunization with TS 100, chickens were subjected to a variety of virus infection and immunosuppressive treatments. Neonatal bursectomy or thymectomy, infectious bursal disease virus infection, and infectious bronchitis virus vaccination or a combination of infectious bronchitis virus and Newcastle disease virus vaccination did not contribute to the development of air-sac lesions in TS MG-immunized chickens. Infectious bronchitis virus vaccination enabled MG to migrate from the nasal cavity to the trachea but not to the air sacs. The TS MG vaccine appears to be a safe immunogen.

A study on Newcastle disease virus pathotypes in Zambia.

Abstract: Summary : Pathotyping of twenty Newcastle disease virus isolates, iso­ lated from field outbreaks during 1982-1983 in the Republic of Zambia, was carried out. Characterisation was based on mean death time, intra­ cerebral pathogenicity index, intracloacal infectivity test and haemagglutinin thermostability test. Fifteen isolates were classified as viscerotropic velogenic and five isolates as neurotropic velogenic NDV strains.

Isolation and biological properties of some Moroccan strains of Newcastle disease virus.

Abstract: SUMMARY Newcastle disease virus was isolated from six field cases in Morocco. On the basis of the mean death time of chicken embryos, the intracerebral pathogenicity index, and plaque formation on chicken embryo fibroblast monolayers, five isolates were determined to be of the velogenic pathotype. One of these differed from the others in that it agglutinated equine erythrocytes. The sixth isolate was found to be of low virulence but differed from the vaccinal strain tested.

Rapid purification of avian influenza virus for use in enzyme-linked immunosorbent assay.

Abstract: A rapid and easy purification method was developed to obtain avian influenza antigen for use in immunochemical assays. This was achieved by rapid concentration of virus from infective allantoic fluid, using 8% (w/v) polyethylene glycol 8000, and later, by purification on gel-permeation chromatography through controlled-pore glass beads. Rabbit anti-turkey globulins were made specific for turkey globulins, using affinity chromatography, conjugated to horseradish peroxidase and used in enzyme-linked immunosorbent assay. A significant increase in specificity and sensitivity of the enzyme-linked immunosorbent assay was observed when purified antigen was used in place of a crude antigen preparation. This purified antigen eliminated the false-positives obtained as a result of the turkeys being previously vaccinated with egg-grown virus vaccines (Newcastle disease virus). The details of the technique and the importance of antigen preparation are discussed.

Newcastle disease vaccination in Malaysia: application of oil emulsion vaccine

Abstract: An experimental oil emulsion Newcastle disease vaccine was evaluated for its efficacy in broiler chickens. A group of chickens vaccinated at one day old with a live lentogenic Newcastle disease vaccine and subsequently revaccinated at three and eight weeks old with the experimental oil emulsion vaccine showed satisfactory haemagglutination inhibition antibody response which persisted for 18 weeks. Between 90 and 100 per cent of the vaccinated chickens were protected when challenged with the velogenic viscerotropic Newcastle disease virus. Although the vaccinated chickens were protected against clinical disease, virus could be isolated from a number of birds. By day 10 to 12 after challenge all the chickens were free from Newcastle disease infection.

Induction potential of Sendai virus and Newcastle disease virus for human lymphoblastoid interferon production.

Abstract: Sendai and Newcastle disease viruses were tested for their induction potential in the production of human lymphoblastoid interferon [HuIFN-alpha(Ly)] from Namalva cell cultures. Tests were performed at multiple induction levels, for two induction periods, and on primed and nonprimed cell cultures. Sendai virus proved statistically more effective overall; priming and induction period had no significant effect.

Herpes simplex virus persistence in mouse neuroblastoma (C 1300) cell cultures: role of interferon.

Abstract: The Mp strain of herpes simplex virus type 1 (HSV1) induced a persistent infection in the mouse C 1300 neuronal cell line (clone N 115). C 1300 cultures infected at an MOI of 0.01 or 0.001 survived the initial infection and continued to produce infectious virus and viral antigens for 185 days and 31 days, respectively. Viral antigens were not detected in cultures no longer producing infectious virus; these “cured” cultures had comparable susceptibility to reinfection with HSV as previously uninfected C 1300 cells. While significant amounts of interferon were produced by C 1300 cells when challenged with Newcastle Disease Virus (NDV) or when treated with poly I:C, HSV-induced interferon could not be detected in either the acutely or persistently infected cell lines. The persistent state was not significantly altered by the addition of 1,000 units/ml of murine interferon alpha plus beta (MuIFNα+β), nor was it affected by the addition of antibody to MuIFN. It appears that IFN does not play an important role in the establishment and/or maintenance of viral persistence in this neuronal system.

Modification of three avian viruses passaged in Chinese hamster lung cells (Don) in pathogenicity to chicken embryo.

Abstract: SUMMARY The Beaudette 42 strain of avian infectious bronchitis virus, Sato strain of Newcastle disease virus, and Uchida strain of avian reovirus were passaged in Chinese hamster lung cells (Don), and some properties were examined. The Don-passaged strains showed a difference in replication in Don and chicken embryo kidney cells in one-step growth curve examinations and a partial modification in pathogenicity to chicken embryos; nevertheless, neutralization tests revealed no serological alteration. RESUMEN

Influence of Newcastle disease and infectious bronchitis live virus vaccines on immune response against infectious laryngotracheitis live virus vaccine in chickens.

Abstract: Efficacy of infectious laryngotracheitis (ILT) live virus vaccine was determined in combination with Newcastle disease (ND) or infectious bronchitis (IB) live virus vaccine by ocular administration to chickens. As for the ILT and IB vaccines, the efficacy of each vaccine was not altered even if both vaccines were inoculated simultaneously. On the contrary, when ILT vaccine was administered simultaneously or contiguously with ND vaccine to young chickens, the marked suppression was observed in ILT immunization. Significant immunosuppression occurred when ILT vaccine was inoculated during the period between 3 days before and 5 days after vaccination with ND vaccine in chickens younger than 5 weeks of age. It did not occur, however, in chickens older than 7 weeks of age or having antibody against ND virus enough to protect growth of the ND virus. These facts show that careful attention must be paid when ILT and ND live virus vaccines are administered to young chickens.