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1.
The safety and the efficacy of several feline leukemia virus (FeLV) vaccines for 16-week-old kittens were determined. Vaccines were derived from an FL74 lymphoblastoid cell line that has been in continuous tissue culture passage for about 4 years. The vaccines were made from living virus, formaldehyde-inactivated whole FL74 cells, and formaldehyde-inactivated whole virus. The efficacy of each produced vaccine was determined by challenge exposure of vaccinated cats with virulent FeLV. The two formaldehyde-inactivated vaccines were found to be safe for use in kittens. Neither vaccine produce a significant feline oncornavirus-associated cell membrane antigen or virus-neutralizing antibody response, nor did they prevent infection with virulent FeLV. The inactivated whole-virus vaccine, however, did substantially decrease the proportion of kittens infected with virulent FeLV that became persistently viremic. In contrast, the whole FL74 cell vaccine did not reduce the number of infected kittens that became persistently viremic. The live-virus vaccine was found to be both safe and efficacious. About a half of the kittens vaccinated with live virus had transient bone marrow infection that lasted from 2 to 4 weeks. Viral antigen was not detected in peripheral blood, and infective virus was not shed in saliva, urine, or feces during the period that the vaccinal virus could be recovered from the bone marrow. In addition, there was no horizontal spread of vaccinal virus from vaccinated to non-vaccinated cagemates. Within several weeks, vaccinated kittens demonstrated no clinical or hematologic abnormalities and had high serum levels of feline oncornavirus-associated cell membrane antigen and virus-neutralizing antibody. Kittens vaccinated with living FeLV were resistant to infection with virulent virus.  相似文献   

2.
Kittens immunized with purified native FeLV-gp70 or -gp85 envelope proteins developed ELISA, but not virus neutralizing, antibodies in their serum to both whole FeLV and FeLV-gp70. Kittens vaccinated with envelope proteins and infected with feline sarcoma virus (FeSV) developed smaller tumors than nonvaccinates, but a greater incidence of persistent retroviremia. Similarly, FeLV-gp70 and -gp85 vaccinated kittens were more apt to become persistently retroviremic following virulent FeLV challenge exposure than nonvaccinates. Kittens vaccinated with inactivated whole FeLV developed smaller tumors after FeSV inoculation and had a lower incidence of persistent retroviremia than nonvaccinates. The protective effect of inactivated whole FeLV vaccine against persistent retroviremia was also seen with FeLV challenge-exposed cats. Protection afforded by inactivated whole FeLV vaccine was not associated with virus neutralizing antibodies, although ELISA antibodies to both whole FeLV and FeLV-gp70 were induced by vaccination.  相似文献   

3.
Twenty young adult specific pathogen-free cats were randomly divided into two groups of 10 animals each. One group was vaccinated with two doses of feline leukemia virus vaccine according to the manufacturer's recommendations. All 20 cats were challenge exposed oronasally (4 times over a 1-week period), beginning 3 weeks after immunization, with a virulent subgroup A strain of FeLV (CT600-FeLV). The severity of the FeLV infection was enhanced by treating the cats with methylprednisolone acetate at the time of the last FeLV exposure. Ten of 10nonvaccinated cats became persistently viremic compared with 0/10 of the vaccinates. ELISA antibodies to whole FeLV were present at high concentrations after immunization in all of the vaccinated cats, and there was no observable anamnestic antibody response after challenge exposure. ELISA antibodies to whole FeLV appeared at low concentrations in the serum of nonvaccinated cats after infection but disappeared as the viremia became permanently established. Virus neutralizing antibodies were detected in 3/10 vaccinates and 0/10 nonvaccinates immediately before FeLV challenge exposure, and in 8/10 vaccinates and 1/10 nonvaccinates 5 weeks later. Although vaccination did not consistently evoke virus neutralizing antibodies, it appeared to immunologically prime cats for a virus-neutralizing antibody response after infection. Active FeLV infection was detected in bone marrow cells taken 14 weeks after infection from 10/10 nonvaccinates and 0/10 vaccinates. Latent FeLV infection was not detected in bone marrow cells from any of the vaccinated cats 14 weeks after challenge exposure.  相似文献   

4.
Transmission of feline leukaemia virus in the milk of a non-viraemic cat   总被引：3，自引：0，他引：3  
The possibility of the transmission of feline leukaemia virus (FeLV) from latently infected cats was studied. Five female cats with latent infections were examined for evidence of transmission of the virus to their kittens. One of the cats infected members of four consecutive litters of kittens which subsequently became persistently viraemic and transmitted the virus to other susceptible kittens by contact. Shortly after birth its kittens were apparently FeLV-free since neither viral antigen nor infectious virus was detected in their blood and no virus was found in cell cultures made from aspirates of bone marrow. The kittens became viraemic from 45 days of age onwards at a time when their passively acquired colostral FeLV neutralising antibodies were no longer detectable. Transmission of the virus occurred via the milk since both FeLV antigen and infectious virus were found in milk samples taken six weeks after kittening and the virus was transmitted to a fostered kitten. Eleven weeks after the birth of the fourth litter the cat became viraemic. The intermittent presence of FeLV antigens detected by the Leukassay F test, but not infectious virus, in the plasma of this cat over the previous months and a low level of serum neutralising antibodies distinguished it from four other latently infected queens which did not transmit infection to their kittens. These factors may indicate a risk of milk transmission and reactivation of latent virus.  相似文献   

5.
Most studies that investigate the prevalence of infections with feline leukemia virus (FeLV) are based on the detection of p27 antigen in blood, but they do not detect proviral DNA to identify the prevalence of regressive FeLV infections. The aim of the present study was to assess the prevalence and status of FeLV infection in cats in Southern Germany. P27 antigen enzyme-linked immunosorbent assay (ELISA), anti-p45 antibody ELISA, DNA polymerase chain reaction (PCR) of blood and RNA PCR of saliva were performed. Nine out of 495 cats were progressively (persistently) infected (1.8%) and six were regressively (latently) infected (1.2%). Cats with regressive infections are defined as cats that have been able to overcome antigenemia but provirus can be detected by PCR. Twenty-two unvaccinated cats likely had abortive infections (regressor cats), testing FeLV antigen- and provirus-negative but anti-p45 antibody-positive. Most of the FeLV-vaccinated cats did not have anti-FeLV antibodies. Both progressive, as well as regressive infections seem to be rare in Germany today.  相似文献   

6.
The performance of a micro ELISA test for detection of feline leukemia virus (FeLV) infection was evaluated. The test was found specific for FeLV and feline sarcoma virus (FeSV) group-specific antigens in blood, plasma or serum of infected cats. Other common feline pathogens were negative to the test.Quantities as little as 7.8 ng of p-27 (the major group specific antigen of FeLV) per ml of sample gave positive results. The correlation between the micro ELISA test and the indirect immunofluorescent test commonly used for diagnosis of FeLV infection was 98% in 116 clinical cases and 184 samples from cats inoculated with FeLV and 100% in 100 specific pathogen-free cats.  相似文献   

7.
Blood samples were analyzed from 30 domestic cats (Felis domesticus) from the Petén region of Guatemala to determine the seroprevalence of common pathogens that may pose a potential risk to native wild felids. Eight of the cats had been vaccinated previously; however, owners were unable to fully describe the type of vaccine and date of administration. In addition, blood samples were obtained from two captive margays (Leopardus wiedii). Samples were tested for antibodies to feline immunodeficiency virus, Dirofilaria immitis, feline panleukopenia virus, feline herpesvirus, feline coronavirus, canine distemper virus, and Toxoplasma gondii and for feline leukemia virus (FeLV) antigen. Fifty percent or more of the cats sampled were seropositive for feline herpesvirus (22 of 30), feline panleukopenia (15 of 30), and T. gondii (16 of 30). Five cats were positive for FeLV antigen. Both margays were seropositive for feline coronavirus and one was strongly seropositive to T. gondii. All animals were seronegative for D. immitis. This survey provides preliminary information about feline diseases endemic to the Petén region.  相似文献   

8.
A new program to address the feral cat population on Prince Edward Island was undertaken during the spring and summer of 2001. Feral cats from specific geographic areas were trapped, sedated, and tested for feline leukemia virus and feline immunodeficiency virus. Healthy cats were neutered, dewermed, vaccinated, tattooed, and released to their area of origin. A total of 185 cats and kittens were trapped and tested during a 14-week period; 158 cats and kittens as young as 6 weeks of age were neutered and released. Twenty-three adult cats were positive for feline leukemia virus, feline immunodeficiency virus, or both, and were euthanized.  相似文献   

9.
A group of 15 cats experimentally infected with a Swiss isolate of feline immunodeficiency virus (FIV) and a group of 15 FIV-negative control cats were inoculated with an FeLV vaccine containing recombinant FeLV-envelope. High ELISA antibody titer developed after vaccination in FIV-positive and FIV-negative cats. Vaccinated and nonvaccinated controls were later challenge exposed by intraperitoneal administration of virulent FeLV subtype A (Glasgow). Although 12 of 12 nonvaccinated controls became infected with FeLV (10 persistently, 2 transiently), only 1 of 18 vaccinated (9 FIV positive, 9 FIV negative) cats had persistent and 2 of 18 had transient viremia. From these data and other observations, 2 conclusions were drawn: In the early phase of FIV infection, the immune system is not depressed appreciably, and therefore, cats may be successfully immunized; a recombinant FeLV vaccine was efficacious in protecting cats against intraperitoneal challenge exposure with FeLV.  相似文献   

10.
Protein (western) blot analysis and virus-neutralization assay were used to evaluate the antibody response of specific-pathogen-free kittens to FeLV vaccination and followed by natural exposure. Several kittens had barely detectable reactions to specific FeLV antigens prior to vaccination or exposure. Correlation was not found between protection against persistent viremia and antibody response after vaccination as measured by western blot analysis or virus neutralization assay. A statistically significant (P less than 0.01) difference in the antibody response against p27 antigen after natural exposure to FeLV was observed between persistently viremic kittens and transiently viremic or aviremic kittens. Measurable (P less than 0.05) virus neutralizing antibody titer after FeLV exposure was found only in a small number of kittens that were protected against persistent viremia. Lack of association between humoral response and vaccination-induced protection against persistent FeLV infection suggests an important role for cell-mediated immunity in such protection.  相似文献   

11.
Two hundred fifty Boston cats with disorders such as lymphosarcoma, myeloproliferative disease, anemia, glomerulonephritis, pregnancy abnormalities, feline infectious peritonitis, toxoplasmosis, and various bacterial infections were examined for feline leukemia virus (FeLV) by immunofluorescence. Antibody titers against feline oncornavirus-associated cell membrane antigen (FOCMA) were tested in 133 of these cats. The tests for FeLV and FOCMA antibody were also conducted among healthy cats not known to have been exposed to FeLV, as well as among healthy cats from households where FeLV was known to be present. Most of the cats with lymphosarcoma and the other aforementioned disorders were infected with FeLV and low FOCMA antibody titers. Healthy cats known to have been exposed to FeLV were often viremic, but those that remained healthy were able to develop high FOCMA antibody titers. Healthy cats without known prior exposure to FeLV were unlikely to be viremic but often had detectable FOCMA antibody titers, indicating that some exposure occurs under natural conditions in the Boston area. The association of FeLV with infections other than lymphosarcoma was assumed to be caused by the immunosuppresive effect of FeLV, thus allowing development of disease.  相似文献   

12.
Use of tears for diagnosis of feline leukemia virus infection   总被引：2，自引：0，他引：2  
A comparison was made of the use of serum, tears, and saliva for the detection of feline leukemia virus (FeLV) infection in cats. Cotton swabs were used to collect saliva, and tear-test strips were used to collect tears. Specimens were analyzed by a commercially available ELISA. Using a 10- to 15-minute specimen incubation period, FeLV was detected in 70% of the saliva specimens and in 73% of the tear specimens from viremic (serum-positive) cats. Feline leukemia virus antigen was not detected in saliva and tear specimens from serum-negative cats. The sensitivity of the tear assay was improved by increasing the incubation time to 24 hours. Tear strips could be air-dried and stored at room temperature for up to 7 days without any appreciable loss of activity. Client-owned and experimentally infected laboratory cats were tested for FeLV, using air-dried tear-test strips and a 24-hour incubation period. Tears were positive (contained FeLV antigen) in 65 of 72 (90%) serum-positive cats and did not contain antigen in 46 of 46 (100%) serum-negative cats. Results of ELISA obtained from serum and tears also were compared with results obtained from indirect fluorescent antibody testing of blood smears. Results of indirect fluorescent antibody and ELISA compared favorably with each other and with the results of tear testing.  相似文献   

13.
Cryptosporidium is a coccidian that can lead to diarrhea, especially in immunosuppressed individuals. Retroviruses are considered a primary cause of immunosuppression in cats. Fecal specimens and blood collected from the 60 cats were evaluated for the presence of acid-fast cryptosporidia in three consecutive stool samples and for feline leukemia virus (FeLV) antigen and feline immunodeficiency virus (FIV) antibody by ELISA testing. Five animals (8.33%) shedding oocysts were found, one was both FIV- and FeLV-negative and four were FeLV-positive.  相似文献   

14.
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15.
Over a 4-year period, 1,683 pound-source cats received at a research institution were screened for feline leukemia virus (FeLV) infection, using an indirect fluorescent antibody test. Viremia was detected in 83 of the cats, for a prevalence of 4.9%. During this period, FeLV infection was detected in 5 kittens on a research project; lymphoma or anemia developed 6 to 17 months after the infections were detected. It was concluded that apparently healthy cats infected with FeLV may not be appropriate for some biomedical research projects.  相似文献   

16.
The seroprevalence of Toxoplasma gondii, Dirofilaria immitis (heartworm), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections was examined using serum or plasma samples from 746 pet cats collected between May and July 2009 from clinics and hospitals located in and around Bangkok, Thailand. The samples were tested for heartworm, FIV, and FeLV using a commercial ELISA. Of the 746 samples, 4.6% (34/746) were positive for heartworm antigen, 24.5% (183/746) had circulating FeLV antigen, and 20.1% (150/746) had antibodies against FIV. In addition, the first 348 submitted samples were tested for T. gondii antibodies using a modified agglutination test (MAT, cut off 1:25); 10.1% (35/348) were seropositive. Of the 348 cats sampled for all four pathogens, 11, 10, and 1 were positive for T. gondii antibodies and FIV antibodies, FeLV antigen, or D. immitis antigen, respectively. Of the 35 T. gondii-seropositive cats, 42.9% (15/35) were co-infected with at least one of the other three pathogens. The presence of antibodies to FIV was significantly associated with both age and gender, while FeLV antigen presence was only associated with age. In the case of FIV, males were twice as likely to be infected as females, and cats over 10 years of age were 13.5 times more likely to be infected than cats less than 1 year of age. FeLV antigen was more common in younger cats, with cats over 10 years of age being 10 times less likely to be FeLV positive than cats under 1 year of age. This is the first survey for these four pathogens affecting feline health in Thailand.  相似文献   

17.
Three adult bengal tigers, 2 immature white tigers, and 3 adult servals were vaccinated IM with three 1-ml doses of a subunit FeLV vaccine with dosage interval guidelines of the manufacturer. All cats had increased antibody titers to FeLV gp 70 capsular antigen and feline oncornavirus cell membrane-associated antigen during the vaccination trial. Three weeks after the third vaccination, 7 of the 8 cats had gp70 antibody titers greater than 0.2 (optical density), and all 8 cats had feline oncornavirus cell membrane-associated antigen antibody titers greater than 1:8.  相似文献   

18.
Tumor necrosis factor alpha (TNF alpha) levels were determined by enzyme-linked immunosorbent assay (ELISA) and by cell culture bioassay in supernatants of lipopolysaccharide-stimulated feline monocyte cultures and in cat serum samples. There was a good correlation between the results obtained by the two methods. From the fact that TNF alpha was neutralized quantitatively by antibodies to human TNF alpha in feline monocyte supernatants and in feline sera, it was concluded that feline TNF alpha immunologically cross-reacts with human TNF alpha and that the human TNF alpha ELISA can be used to quantitate feline TNF alpha. During the first 6 months after experimental feline immunodeficiency virus (FIV) infection no differences in serum TNF alpha values were observed between infected and non-infected cats. TNF alpha levels increased significantly after primary vaccination with a feline leukemia virus (FeLV) vaccine in FIV infected cats over those in the non-infected controls. During secondary immune response TNF alpha levels rose transiently for a period of a few days in both the FIV positive and the FIV negative cats. After FeLV challenge, TNF alpha levels increased in all animals challenged with virulent FeLV for a period of 3 weeks. This period corresponded to the time necessary to develop persistent FeLV viremia in the control cats. It was concluded from these experiments that in the asymptomatic phase of FIV infection no increased levels of TNF alpha are present, similar to the situation in asymptomatic HIV infected humans. Activation of monocytes/macrophages in FIV infected cats by stimuli such as vaccination or FeLV challenge readily leads to increased levels of TNF alpha.  相似文献   

19.
The objective of this study was to determine whether intranasal administration of a commercially available FVRCP vaccine to kittens lessened clinical signs and feline herpesvirus 1 (FHV-1) viral shedding when compared to unvaccinated control kittens after FHV-1 challenge. Three groups of 10 unvaccinated kittens were administered one dose of vaccine 6 days (group 1), 4 days (group 2), or 2 days (group 3) before challenge, respectively. One group was maintained as unvaccinated controls (group 4). FHV-1 challenge was then induced and the kittens were observed for 14 days. When the grouped vaccinated kitten results (groups 1-3) were compared to group 4 results, clinical scores following challenge were significantly lower (P<0.05) and significantly lower body temperatures (P<0.05) were detected on days 0, 5 and 9 post-challenge. When evaluated by individual group, group 1 and group 2 kittens had significantly lower clinical scores (P<0.05) than group 4 kittens post-challenge. In addition, FHV-1 shedding was lower in group 1 kittens when compared to group 4 kittens on day 6 after challenge (P<0.05). Administration of this vaccine within several days prior to exposure lessened clinical signs of disease and FHV-1 shedding compared to unvaccinated kittens.  相似文献   

20.
Five- to six-month-old specific-pathogen-free cats were exposed to cobra venom factor (CVF) alone (4 cats), Rickard feline leukemia virus (FeLV; 9 cats), or CVF and FeLV (6 cats). Host-virus relationships were evaluated by monitoring the development of viremia, production of antibody against feline oncornavirus-associated cell membrane antigen, and amount of circulating immune complexes (CIC). Exposure to CVF induced complement depletion, which lasted 8 to 15 days. However, complement depletion did not promote the development of persistent viremia nor alter the production of antibody to feline oncornavirus-associated cell membrane antigen or CIC. Results indicated that the complement system did not protect cats during their initial exposure to FeLV and that an intact complement system was not necessary for the development of antibody against feline oncornavirus-associated antigen or for the formation of CIC.  相似文献   

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