Vance J. Yates

Isolation of a viral agent causing hematopoietic neoplasia in the soft-shell clam, Mya arenaria☆

Abstract A virus from neoplastic soft-shell clams, Mya arenaria, has been isolated. Its morphological and physical properties are similar to those of B-type retroviruses. It is enveloped, pleomorphic, averaging 120 nm in size with an eccentric nucleoid. Possible A-type particles have also been observed. The bouyant density of the particle ranged from 1.17 to 1.18 g/cm3 and the ultraviolet absorption 260 280 - nm ratio was 1.23. The virus has been shown to cause a hematopoietic neoplasm in Mya. Purified virus from neoplastic clams was innoculated into nonneoplastic clams. Most of these clams developed tumors within 2 months. Virus isolated from inoculated clams which developed neoplasia was inoculated into nonneoplastic clams. Most of these clams also developed neoplasia thus completing Kochs postulates.

An Enzyme-Linked Immunosorbent Assay for Detection of Antibodies to Avian Adenovirus and Avian Adenovirus-Associated Virus in Chickens

An enzyme-linked immunosorbent assay system (ELISA) was adapted for the detection of antibodies to avian adenovirus (AV) and avian adenovirus-associated virus (A-AV). Both before and after exposure, sera from chickens undergoing natural and experimental infections were assayed by ELISA, virus neutralization (VN), and immunodiffusion (ID) for antibody to both CELO virus and A-AV. The ELISA system was found to be comparable to VN for determining antibody concentrations to CELO virus and A-AV. In many cases, ELISA was found to be more sensitive than ID.

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

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.

Effect of Avian Adeno-Associated Virus on Pathogenicity of Tipton Virus in Chicks

The avian adeno-associated virus (A-AV) reduced the pathogenicity of an adenovirus infection in vivo. Groups of chicks were infected with Tipton virus alone or in combination with high or low doses of A-AV. In both trials, the associated virus delayed and reduced chick mortality. This effect was dose-dependent and significant at the higher dose level.

EVIDENCE OF EXPOSURE OF WATERFOWL AND OTHER AQUATIC BIRDS TO THE HEMAGGLUTINATING DUCK ADENOVIRUS IDENTICAL TO EDS-76 VIRUS

Serum and fecal samples from 12 species of aquatic birds were studied for evidence of exposure to a hemagglutinating duck adenovirus (DAV). DAV is serologically indistinguishable from egg-drop syndrome-76 virus. A total of 285 serum samples were tested by the hemagglutination-inhibition (HI) test. Forty-two percent of the birds had HI antibodies, with titers ranging from 8 to 256. Wild ducks showed the highest frequency of antibodies (56%) while in coots and grebes, antibody was less frequent, 33% and 26%, respectively. Attempted virus isolations from 79 fecal samples were unsuccessful. The data support the hypothesis that DAV is indigenous in wild duck populations and suggest that infection and viremia are limited in time and occur at a very early age.

Serological response of chickens exposed to a type 1 avian adenovirus alone or in combination with the adeno-associated virus.

The avian adenoviruses (AV) are common infectious agents of poultry and other avian species throughout the world (1,4,8). Limited observations suggest that the adeno-associated virus (A-AV) coinfects many of the chickens that carry AV (8). The presence and persistence of these infections in a flock is often determined by serological methods. In the current study, the immune response of chickens to type 1 AV alone and to a dual exposure, AV plus A-AV, was followed over a 12-week period with a variety of serological tests. The study also determined the duration of the viral infections.

Reactions of Human Sera to Avian Adenoviruses and Newcastle Disease Virus

The sera of two human populations were examined for antiviral reactions to avian adenoviruses and to Newcastle disease virus (NDV). Group I had close contact with poultry; Group II had limited association. None of the sera reacted with the avian adenoviruses used. Sera of Group I individuals had a high frequency of NDV hemagglutinin inhibitory (HI) activity; Group II sera showed no such reactions. Sera of both groups showed a low frequency of reactors having NDV neutralizing antibody. Neutralizing activity could not be related to HI activity of the sera. The HI activity observed was apparently not due to cross reactions with mumps antibody.

Some observations of the propagation of infectious laryngotracheitis virus in tissue culture.

HE virus of infectious laryngotracheitis (LT) produced cytopathogenic effect (CPE) and plaques in chick-embryo fibroblast and respiratory epithelium.1 However, Buthala, et a.3 was unable to find CPE with LT virus in chick-embryo kidney cells, although the virus proliferated in the cell culture. The present study had three objectives: 1. to study the effect of LT virus in chick-embryo kidney cells and its ability to produce CPE and plaques, 2. to attempt the isolation of the virus by plaque method from chickens artificially or naturally infected with LT virus, 3. to study the differences between plaques formed by LT virus, chick-embryo-lethalorphan (CELO) virus and Newcastle disease (ND) virus.

Cultivation of avian encephalomyelitis virus in vitro. 2. In chick embryo fibroblastic cell culture.

virus N (Dinter, 1949). Bul. Inst. Sierter Milanese 45, 255-272, 1966. 22. Roberts, D. H. The isolation of an influenza A virus and a mycoplasma associated with duck sinusitis. Vet. Record 76, 470-473, 1964. 23. Shope, R. E. The swine lungworm as a reservoir and intermediate host for swine influenza virus. J. Exptl. Med. 102, 567-572, 1955. 24. Simmins, G. B., and F. D. Asplin (1956). Cit. by Roberts, 1964. 25. Simmons, J. A., and C. J. Gentzkow. Laboratory methods of the United States Army. 6th ed., pp. 862, 1955. Lea and Febiger.

Comparison of Enzyme-linked Immunosorbent Assay with Hemagglutination-Inhibition and Immunodiffusion Tests for Detection of Antibodies to a Hemagglutinating Duck Adenovirus In Chickens

An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of antibody to a hemagglutinating duck adenovirus is described. Optimum conditions for the test were determined, and the system was compared with procedures currently used. Experimentally infected chickens were assayed for specific antibody by ELISA, hemagglutination inhibition (HI), and immunodiffusion (ID). The ELISA was a sensitive and reliable method for detecting antibody, although positive titers were not always in agreement with HI and ID results at 1 week postinoculation, probably reflecting the different classes of antibody being detected.