Showing papers on "Newcastle disease published in 1980"

Mutational changes of the protease susceptibility of glycoprotein F of Newcastle disease virus: effects on pathogenicity.

Abstract: Two chemically induced mutants with an alteration in the susceptibility of glycoprotein F to proteolytic cleavage have been isolated from the apathogenic strains of La Sota and Ulster of Newcastle disease virus. In contrast to the La Sota wild type, cleavage of the precursor F0 and activation of cell fusing activity and infectivity take place if the mutant is grown in MDBK and BHK21-F cells. The mutant is, therefore, able to undergo multiple replication cycles in cells non-permissive for the wild type. This increase in host range is paralleled by an increase in pathogenicity for chick embryos. The increase in host range of the Ulster mutant is less distinct. This mutant, which does not differ in pathogenicity from its wild type, produces in MDBK cells incompletely activated virus containing predominantly glycoprotein HN in the uncleaved and glycoprotein F in the cleaved form. The data support the concept that the susceptibility of the virus glycoproteins to proteolytic activation is an important factor in determining the pathogenicity of this virus.

Historical note on the origin of the LaSota strain of Newcastle disease virus.

Abstract: It has been more than thirty years since live-virus Newcastle disease vaccines were introduced for use in poultry production. One aspect of the situation has never been reported: the complete history of the LaSota strain of vaccine virus, now used throughout the world. The writer is the last person alive who had intimate knowledge of the situation; the others were Dr. Fred R. Beaudette, Dr. Arthur D. Goldhaft, Dr. Nathan E. Wernicoff, and Charles B. Hudson.

Performance of 3 successive generations of specified-pathogen-free chickens maintained as a closed flock

Abstract: No antibodies against Salmonella pullorum, Mycoplasma gallisepticum, Mycoplasma synoviae, Haemophilus gallinarum, fowl pox virus, Marek's disease virus, herpes virus of turkey, infectious laryngotracheitis virus, avian adenovirus, avian reovirus, infectious bursal disease virus, reticuloendotheliosis virus, avian leukosis virus, avian encephalomyelitis virus and Newcastle disease virus were detectable in the sera obtained from these chickens in 3 generations at various ages. Antibodies against infectious bronchitis virus were detected in the sera of the 3rd generations at 66, 74 and 108 weeks of age. The performances of these chickens was nearly the same as that of conventional healthy chickens in the poultry industry, with no tendency to decline.

Viscerotropic Velogenic Newcastle Disease In Pigeons: Clinical Disease and Immunization

Abstract: SUMMARY Racing homer pigeons were exposed to viscerotropic velogenic Newcastle disease virus (VVNDV) to further characterize the disease in pigeons. Mortality was 7 of 21 juvenile birds and 1 of 10 adult birds. Virus shedding was detected until 21 days postinoculation in some birds. Pigeons infected experimentally shed VVNDV before the onset of clinical disease and were able to transmit VVNDV to chickens and pigeons by contact exposure. Pigeons were also susceptible to infection with VVNDV by contact exposure to an infected chicken. In experiments in which 3 commercial Newcastle disease virus (NDV) vaccines were used to evaluate several vaccination programs, only 1 of the programs completely prevented morbidity and mortality following VVNDV challenge 6 weeks after the final vaccination. Pigeons in that program were vaccinated with viable vaccine and revaccinated at 6 weeks postvaccination with inactivated oil-emulsion vaccine.

The Pathogenicity of Newcastle Disease Virus Isolated from Migrating and Domestic Ducks and the Susceptibility of the Viral Glycoproteins to Proteolytic Cleavage

Abstract: Besides the chicken, other poultry are known to be susceptible to Newcastle disease virus (NDV) (9), and the virus appears to be distributed widely in various wild birds as indicated by isolation of new NDV strains from such birds (10, 11). We considered it to be of ecological interest to learn the properties of such virus strains since there is a possibility that some species of wild birds act as a reservoir from which the infection in fowls arises. Recently evidence that pathogenic and apathogenic strains of NDV differ from each other with respect to the susceptibility of the viral glycoproteins to proteolytic cleavage was obtained (4, 6). The glycoproteins of pathogenic strains are readily cleaved to become biologically active molecules in all types of host cells tested, whereas those of apathogenic strains are cleaved only in the endoderm of the chorioallantoic membrane of the chick embryo but not in most other cells. On the basis of these studies we have characterized five new NDV strains, D-13, D-26, D-28, D-43, and D-49, which were recently isolated from various migrating and domestic ducks in Japan by Yamane et al (11). The stock viruses were grown in the allantoic cavity of 11-day-old chick embryos. The capacity of the viruses to kill chick embryos was determined by measuring the mean death time (MDT) of the embryo after inoculation of 102.5 EID50 of the viruses into the allantoic cavity of 11-day-old chick embryos (9). Labeling of virus with [3H]-glucosamine (New England Nuclear Corp., 10-30 Ci/mmol) in MDBK cells and isolation of the labeled virions were carried out as described previously (4, 5). To analyze proteins and glycoproteins, virions were dissociated with 2% sodium dodecyl sulfate (SDS) and 5% 2-mercaptoethanol and subjected to electrophoresis on polyacrylamide slab gels in Tris-glycine buffer with SDS (2). [3H]-glucosamine on the gels was detected by scintillation autography (1). Hemagglutinin, neuraminidase and hemolytic activities were determined as described previously (4). Infectivity titers were determined by infective doses for MDBK cells as indicated by the production of detectable amounts of hemagglutinin (8). First we examined the virulence of the newly isolated strains for chick embryos by determining the MDT. All of the five strains were found to have an MDT of

Collection and processing of blood samples dried on paper for microassay of Newcastle disease virus and avian influenza virus antibodies.

Abstract: A practical method for collection and processing of dried whole blood samples on filter paper was developed to facilitate large-scale testing programs for Newcastle disease virus and avian influenza virus antibodies. A modified paper punch was used to cut and place dried blood samples simultaneously in a standard 96-well microlate for elution of antibody. Twelve eluted samples were simultaneously transferred to another microplate for the hemagglutination-inhibition (HI) microtest. Similar HI titers were obtained with simultaneously collected serum and dried blood samples. Minor differences were not considered of practical importance in diagnostic serologic studies. Dried blood titers were not markedly affected by method of drying (37 C for 2 hours or 26 C for 4 hours), by storage for 24 hours before drying, or by storage of dried samples at 4 C for 28 days or 30 C for 14 days. Blood dried on paper was a satisfactory sample for assay of HI antibodies to Newcastle disease virus and avian influenza virus.

Immune Response of White Leghorn Chicks from Vaccination With Different Strains of Infectious Bursal Disease Virus and In the Presence of Maternal Antibodies

Abstract: SUMMARY White Leghorn chicks 1 to 11 days old possessing maternal antibodies to infectious bursal disease (IBD) were vaccinated with the 2512-P48, 2512-P84, LKT, and BV strains of IBD virus by different routes. Their dams had been vaccinated against IBD at one day old and revaccinated at 14 weeks and every 90 days thereafter. The 2512-P48, 2512-P84, and LKT strains did not bestow satisfactory immunity on the progeny as measured by challenge and the agar-gel precipitin test. In contrast, the BV strain engendered good immunity when used as a vaccine at as early as 4 days old. Moderate lesions were found histologically in the cloacal bursa in the postvaccination period, although no clinical signs of IBD were noted. Significant immunosuppression did not occur when chicks were vaccinated with BV IBD virus at 4 days old, vaccinated against Newcastle disease 7 days later, and subsequently given Newcastle disease challenge virus. Primary vaccination of White Leghorn chicks to be placed in IBD-endemic areas in the field is discussed with reference to susceptibility to virus infection, vaccination status of the breeders, level of maternal antibodies (7), and the need for using IBD vaccine strains of differing degrees of virulence and immunogenicity to meet frequently varying field conditions.

Evaluation of inactivated Newcastle disease oil-emulsion vaccines.

Abstract: Three commercial European inactivated oil-emulsion (OE) vaccines and a U.S.-licensed inactivated AI(OH)3 vaccine were evaluated by primary vaccination of susceptible broilers and by secondary vaccination of layers previously immunized with live virus. A commercial live-virus vaccine was also used as a primary and secondary vaccine control. Evaluation was based on the hemagglutinationinhibition (HI) response and protection against challenge with neurotropic or viscerotropic velogenic (VV) Newcastle disease virus (NDV). OE vaccines induced higher and generally more sustained HI antibody titers than AI(OH)3 or live vaccines. With one exception, all challenged OE vaccinates were protected against clinical disease, a drop in egg production, and a decrease in egg quality. Vaccination did not prevent infection with the challenge viruses; however, the infection rates were lowest in LaSota vaccinates and highest in Al(OH)3 vaccinates.

The immune response of chickens vaccinated against Newcastle disease with live Newcastle disease V4 vaccine.

Abstract: Vaccination of chickens with the commercial Newcastle Disease (ND) V4 vaccine at 21 days old or at 21 and 35 days old, stimulated satisfactory and persistent HI antibody levels. The vaccinated chickens were immune when challenged at 49 days old or 77 days old with the virulent strain of NDV administered intramuscularly, intranasally or by contact. Postmortem findings of the non-vaccinated and vaccinated chickens that died from the challenge were recorded.

The response of australian chickens naturally infected with avirulent newcastle disease virus to challenge with velogenic newcastle disease virus

Abstract: SUMMARY Sixty‐eight breeder chickens, 4 to 12 months of age, were taken from Australian flocks that had been naturally infected with avirulent Newcastle disease virus (NDV) and transported by air to Malaysia. Nearly all the breeders had haemagglutination inhibition antibodies to NDV, at titres of from 2 to 128. Thirty‐two were inoculated intranasally with an Asian, velogenic, viscerotropic strain of NDV and all survived this challenge. Thirty‐six were exposed to contact infection with the same velogenic NDV and 2 died of Newcastle disease within 14 days. The levels of haemagglutination inhibition antibodies against NDV increased in the surviving breeders after challenge, reaching 2048 or greater in a few birds. Velogenic NDV was isolated from a cloacal swab from one clinically normal breeder 10 days after challenge by contact. Cloacal swabs taken 7 to 10 days after challenge from another 23 breeders yielded no NDV. Twenty‐four broilers, 7 weeks of age, were also transported from Australia to Malaysia. All lacked detectable haemagglutination inhibition antibody to NDV and they were from a flock with no detectable antibody to NDV. Twelve were challenged with velogenic NDV intranasally and 12 were subjected to contact challenge. All broilers died of Newcastle disease within 13 days.

Characterization of nine avian paramyxoviruses.

Abstract: SUMMARY Nine avian paramyxoviruses were isolated from tracheal and cloacal swabbings of feral ducks and geese in the Atlantic Flyway. Inoculation of the viruses into specific-pathogen-free chicken embryos resulted in sporadic mortality. The allantoic fluids from infected embryos agglutinated chicken and rat erythrocytes but the isolants were found to be serologically unrelated to influenza virus type A, Newcastle disease virus, Yucaipa virus, and turkey/Wisconsin/68. On the basis of hemagglutination-inhibition and virusneutralization tests, the viruses were separated into 6 antigenic groups which were supported by similarities in biological and physicochemical properties of the isolants. Biological characterization showed that 8 of the isolants possessed hemagglutinin that was stable for less than 15 minutes at 56 C, whereas the hemagglutinin of the remaining virus was stable between 15 and 30 minutes. Investigation of the elution times revealed 4 rapid-eluting viruses, 1 moderate-to-rapid eluter, and 4 slow-eluting viruses. The isolants were capable of replication in Vero cell cultures, resulting in varying degrees of cytopathology. Intracerebral inoculation of one-dayold chicks and turkeys produced intracerebral pathogenicity indices similar to those of lentogenic strains of Newcastle disease virus. Intranasal inoculation of 12-day-old broiler chickens (Hubbard X Hubbard) and turkeys (Diamond White Hybrid) induced a mild respiratory disease. Two of the isolants were recovered from the tracheas of inoculated birds at 4 and 10 days postinoculation. Physicochemical characterization showed that all the isolants were Published with the approval of the Director of the Delaware Agricultural

Potency of live Newcastle disease vaccines.

Abstract: Summary A comparison was made of the potency of live lentogenic Newcastle disease vaccines using a multipoint challenge assay. In general, La Sota vaccines gave better protection than B1 vaccines and both were superior to products made from the Ulster 2C strain. However, variation was found within products prepared from the same strains, depending on their source. Two novel types of vaccine derived from the conventional B1 or La Sota strains were as protective as La Sota vaccines and a third gave protection similar to that of B1 vaccines.

Characteristics of lentogenic strains of Newcastle disease virus isolated in New Zealand

Abstract: Newcastle disease has not been recognised as a clinical entity in New Zealand, but several isolates of the causative virus have been obtained from domestic fowls, wild mallard ducks and an illegally imported parrot from Fiji. The viruses we obtained grew to high titre in fertile eggs, but embryonic death-rates were low, the patterns of death were-irregular and mean death-times were long. Transmission tests in day-old and older chickens caused no clinical disease. No drop in egg production was observed in laying birds. The-isolates were found to elute slowly from chicken erythrocytes, to show variable agglutinating activity with horse erythrocytes, and, especially those isolated from ducks, to be heat stable. They all failed to produce plaques in under 96 hours except in the presence of Mg SO4 or DEAE-dextran. It was concluded the isolates were of the lentogenic type and were virtually avirulent.

An outbreak of Newcastle disease in a pheasant flock in Iraq.

Abstract: Summary A highly virulent strain of Newcastle disease virus (NDV) was isolated from pheasants in an unvaccinated private imported flock in the Rathwania area near Baghdad, Iraq, which was suffering from ND. The virus was propagated in 9‐day‐old specific pathogen‐free chicken embryos. It was characterised by the following tests: intracerebral pathogenicity index (ICPI), intravenous pathogenicity index (IVPI), mean death time (MDT), haemagglutinin stability at 56°C and mammalian erythrocyte agglutination. The ICPI, IVPI and MDT for the virus were: 1.89, 2.63 and 64 hours respectively. The stability of its haemagglutinin at 56°C was 120 minutes. It agglutinated chicken and pheasant but not bovine, equine and human type “O” erythrocytes.

Development of the AG68L strain of Newcastle disease vaccine. (1) Modification of the existing AG68L vaccine by clone purification and its subsequent testing.

Abstract: Summary After preliminary work had shown that the Newcastle disease vaccinal strain AG68L had considerable potential as a lentogenic vaccine for administration in the drinking water, it was studied for viral homogeneity and purified by plaque picking and cell culture passage. The fifth passage of a small plaque was used to immunise birds. Its performance was compared with LaSota virus and with the parent AG68L. The attenuated vaccine was found to be significantly more immunogenic than LaSota virus when administered in the drinking water to either fully susceptible or maternally immune chicks; it was shown to be significantly less pathogenic than the parent strain and slightly more pathogenic than the LaSota strain when given as an aerosol but without detectable pathogenicity when given in the drinking water.

Effect on influenza virus infection on the production of interferon by alveolar and peritoneal cells in vitro.

Abstract: The investigation was carried on mice infected with influenza A/053/74/H3N2 virus. 129/Ao/Boy, inbred mice, were inoculated intranasally with influenza virus. The alveolar and peritoneal cells from infected and uninfected animals were induced in vitro with Newcastle disease virus. It was shown that the alveolar cells from infected mice produce more interferon than the cells from control mice, but the peritoneal cells from both groups of animals produced the same amount of interferon.

Effects of the androgen analog mibolerone on clinical and subclinical infectious bursal disease.

Abstract: Mibolerone treatment (1.5 Agg/g feed) did not diminish the immunosuppressive effects of an early exposure (1 day old) to infectious bursal disease virus (IBDV) as indicated by Newcastle disease virus (NDV) hemagglutination-inhibition serological responses and resistance to NDV challenge following vaccination with an inactivated NDV vaccine at 14 days old. Treating SingleComb White Leghorn chickens free of IBDV-specific maternal antibody with mibolerone (1.5 pAg/g of feed for the first 4 weeks of life) decreased clinical and serological responses to IBDV infection at four weeks old. This was evidenced by lower levels of IBDVneutralizing and precipitating antibody as well as an increased resistance to clinical IBD.

Decreased egg production in a turkey breeder flock associated with Newcastle disease virus.

Abstract: SUMMARY Newcastle disease virus recovery and rising hemagglutinationinhibition (HI) titers were associated with a drop in egg production in a turkey breeder flock previously vaccinated for Newcastle disease.

Susceptibility of Influenza Viruses to Interferon and to Poly (I) · Poly (C) Determined by the Plaque Reduction Method

Abstract: Susceptibility of eight strains of influenza A and B viruses to interferon and to poly(I) · poly(C) were determined by the plaque reduction method. All strains tested were slightly less susceptible than vesicular stomatitis virus (VSV) in an established line of canine kidney (MDCK) cells. The 50% plaque depression doses (PD50) of poly(I) · poly(C) for influenza A and B viruses were as high as 3.0- to 4.5-fold and 6- to 18-fold that for VSV, respectively. The amounts of interferon required to inhibit plaque formation of influenza A and B viruses by 50% were 3.0–6.2 and 7.3–15.2 units/ml, respectively. The ratio of PD50 of poly(I) · poly(C) for each strain of influenza viruses tested to that for VSV in chick embryo cells was almost the same as in MDCK cells. Furthermore, in chick embryo cells, the strains of influenza virus tested were demonstrated to be much more susceptible to poly (I) · poly(C) than both Newcastle disease virus and vaccinia virus. It is suggested that influenza viruses may be relatively susceptible to interferon and to poly(I) · poly(C).

["Pharaoh" line culture of Japanese quail cells as a leukosis-free system for virus reproduction].

Abstract: Contamination of Japanese quail, strain Pharaoh, cell culture with oncogenous and infectious avian viruses was studied. The susceptibility of the embryonal cell cultures of the Japanese quail, strain Pharaoh, to measles, parotitis and fixed rabies viruses was also determined. It was found that the sera of pubertal quails had no antibody to Rous sarcoma virus (RSV), strains Brian, RSV (RAV-1), Schmidt-Ruppin, Carr-Zilber, as well as to Marek's disease and Newcastle disease viruses. No reverse transcriptase activity was detected in the embryonal alantoic fluid of this avian species. The quails were less susceptible, as compared to the chicken, to Schmidt-Ruppin and Carr-Zilber strains of RSV. Measles, parotitis and fixed rabies viruses reproduced actively in the Japanese quail, Pharaoh strain, embryonal cell cultures. It is suggested that the embryonal cell cultures of this avian species can be used as a leukemia-free substrate for experimental studies and manufacturing of viral vaccines.

Interferon and humoral immune response in experimental influenza: infection with A/PR8 virus adapted to the mouse.

Abstract: Inbred 129/Ao/Boy mice were infected with various doses of AO/PR8/HONI influenza virus. Replication of virus, synthesis of endogenous interferon and antibodies were measured. The infected mice were the source of alveolar and peritoneal cells which were used for the in vitro induction of interferon with Newcastle Disease virus (NDV). It has been found that the level of interferon detected in the tracheo-bronchial washings parallels the titer of virus in the lung. At the lethal doses of the virus interferon appeared earlier but its titer also declined faster than in mice infected with sublethal doses of influenza virus. The peritoneal and alveolar cells from the mice infected with the lethal doses of influenza virus produced less interferon after the induction with NDV than the cells from uninfected mice. In contrast, the alveolar cells from mice infected with sublethal doses of A/PR8 virus produced more interferon than the control cells.