Function of feline signaling lymphocyte activation molecule as a receptor of canine distemper virus.
(17/31)
Morbilliviruses use signaling lymphocyte activation molecule (SLAM) as a receptor for their entry to cells. In this study, a complete gene encoding SLAM of a domestic cat was identified. The identity of feline SLAM with canine one was 73%, and feline SLAM formed the same cluster with those of carnivores. Furthermore, feline cell expressing feline SLAM supported growth of canine distemper virus (CDV) as well as that expressing canine one. These results indicated that feline SLAM can function as a receptor for morbilliviruses, and our established feline cells that express feline SLAM might be useful for analysis of morbilliviruses originated from felids. (+info)
Co-infection with feline and canine parvovirus in a cat.
(18/31)
In this study we reported a case of co-infection with canine parvovirus (CPV) type 2a and feline panleukopenia virus (FPV) in a 3-month-old male kitten, with the presence of a parvovirus variant which is a true intermediate between CPV and FPV. The report of a viral variant which contained FPV- and CPV-specific epitopes stresses the importance of the mechanism of multistep mutation in the production of new variants and in the emergence of new viruses. This type of multistep adaptation has already been documented during the emergence of CPV and on the basis of our results, it was hypothesized that CPV had presumably started a new process of readaptation in the feline host, confirming the importance of viral host switching as a mechanism for the emergence of new viruses. (+info)
Feline parvovirus propagates in cat bone marrow cultures and inhibits hematopoietic colony formation in vitro.
(19/31)
Feline parvovirus (FPV) causes leukopenia in naturally infected cats. We investigated the mechanism of hematopoietic depression by this virus in feline bone marrow cultured in vitro. In suspension cultures we demonstrated FPV propagation and replication using DNA molecular hybridization. Viral RNA and DNA were observed by in situ hybridization in about 10% of marrow cells at day 3. Granulocytes and their precursors were virtually absent from infected cultures after six days. Infected cells showed viral capsid protein predominantly in nuclei by immunofluorescence. In clonal assays, FPV most efficiently inhibited hematopoietic colony formation by myeloid progenitor cells (CFU-GM), but erythroid colony formation (BFU-E and CFU-E-derived) was also depressed in the presence of virus. Inhibition of colony formation could be abrogated by physical inactivation of the virus or preincubation with specific neutralizing antibodies. Recombinant human colony stimulating factors GM-CSF and G-CSF supported feline myelopoiesis in progenitor assays, and FPV completely inhibited factor dependent colony formation. (+info)
Feline leukemia virus-associated enteritis--a condition with features of feline panleukopenia.
(20/31)
Infection with feline leukemia virus (FeLV) was demonstrated immunohistologically in 218 necropsied cats suffering from enteritis. The animals were divided into three groups according to histopathological criteria. The first group exhibited the signs of feline panleukopenia in intestine, lymphoid tissues, and bone marrow. Only 1.6% of these animals were FeLV-infected. The animals of the second group had histopathological alterations as seen in cats suffering from feline panleukopenia, but these were found only in the intestine and not in lymphoid tissues or bone marrow. Of these 71.9% were infected with FeLV. The third group consisted of all other cats suffering from enteritis of which 6.3% were FeLV-positive. The association between FeLV infection and the lesions seen in the animals of group 1 (feline panleukopenia) and group 3 (other types of enteritis) is statistically not significant whereas the alterations exhibited by the cats of group 2 are significantly FeLV-associated. Cats with FeLV-associated enteritis (group 2) are of a mean age of about 2.5 years and are significantly older than animals with feline panleukopenia which are of a mean age of about half a year. Thus a FeLV-associated enteritis exists as a histopathologically recognizable condition which sometimes might be mistaken for feline panleukopenia in routine post-mortem investigations. (+info)
Pathological changes in virus enteritis of mink.
(21/31)
The lesions which characterize viral enteritis of mink (VEM) were studied in twenty-six, ten-week-old mink which had been infected by force feeding a tissue suspension containing a Wisconsin strain of mink enteritis virus. The pathogenesis of the lesions was reconstructed from gross and histopathological changes observed in animals which were selected randomly from the group each day for necropsy during the course of the disease. Alterations were observed in the tissues of all mink examined from post-inoculation day (PID) 4 through 13. The principal macroscopic lesions which consisted of fibrinous enteritis, enlargement and hemorrhage of the spleen and edema of mesenteric and hepatic lymph nodes were most conspicuous on PID 7 and 8. Histopathological changes including necrosis and desquamation of intestinal epithelium, depletion of mature lymphocytes in lymph nodes, thymus and spleen and loss of partly differentiated myeloid and erythroid cells from spleen and bone marrow also reached full development on PID 7 and 8. However, nuclear inclusion bodies which were presumed to be a product of the causative agent and, therefore, of diagnostic significance were most prevalent on PID 3, 4 and 5. The inclusions were observed in mucosal epithelial cells of the intestine, parenchymal cells of the liver and in lymphocyte precursor cells of the spleen, intestinal lymph nodules and masenteric and hepatic lymph nodes. (+info)
Antigen and antibody in Aleutian disease in mink. II. The reaction of antibody with the Aleutian disease agent using immunodiffusion and immunoelectroosmophoresis.
(22/31)
Aleutian disease viral (ADV) antigen was prepared by fluorocarbon extraction of spleen, liver, and lymph nodes from mink experimentally infected ten days previously. Using a potent ADV antigen, antibody was detected by immunodiffusion (ID) and immunoelectroosmophoresis (IEOP). Utilizing these precipitin tests, antibody was detected in all the mink sera tested as early as seven days after experimental infection. Titer of antibody increased throughout the infection period. Titers of more than 100 were reached by 15 days post infection, titers of 1,000 at one month, and titers of more than 5,000 to 10,000 were achieved at two months post infection and thereafter. The immunodiffusion test gave similar or slightly lower titers than those detected by the IEOP. The IEOP test promises to be a most useful technique for the diagnosis of aleutian disease because it is simple, rapid and specific and is capable of detecting infection early in the course of the disease. It is suggested that this test should be utilized especially for the screening of animals purchased or imported as breeding stock onto ranches. (+info)
Study of an attenuated strain of feline infectious enteritis (panleucopaenia) virus. I. Spread of vaccine virus from cats affected with feline respiratory disease.
(23/31)
In the course of developing a living attenuated feline infectious enteritis (panleucopaenia) vaccine, it was found that respiratory disease-infected cats newly inoculated with this vaccine spread vaccine virus to respiratory disease-infected in-contact controls. These in-contact controls were able to infect other cats with which they were placed in contact so that after five natural transmissions in this way and two oral administrations and subsequent re-isolations, reversion to virulence became evident. It is clear that before general release of a new living feline infectious enteritis vaccine, there must be satisfactory evidence that concurrent infection will not affect the safety of the modified antigen.In cats infected with feline infectious enteritis there appears to be a short period, coinciding with the onset of leucopaenia, during which they are highly infectious. It seems possible that some infected animals may become immune carriers because virus has been recovered from the small intestine of two of four cats with significant antibody titres 22-24 days after exposure to infection. (+info)
Study of an attenuated strain of feline infectious enteritis (panleucopaenia) virus. II. Removal of the spread factor by further passaging in tissue culture.
(24/31)
The propensity of an attenuated strain of feline infectious enteritis (panleucopaenia) virus to spread from vaccinated cats affected with intercurrent feline respiratory disease to unvaccinated in-contact cats was eradicated by further passaging of the vaccine virus in tissue culture. No virus was recovered from, and no antibody was found in the sentinel cats in contact with seven vaccinated animals. Thus, a further 27 passages of the vaccine virus in tissue culture has eliminated the spread factor. (+info)