Isolation of feline parvovirus from peripheral blood mononuclear cells of cats in northern Vietnam.

Feline parvovirus (FPV) was isolated rather frequently from the peripheral blood mononuclear cells (PBMCs) of cats in northern Vietnam by coculturing with MYA-1 cells (an interleukin-2-dependent feline T lymphoblastoid cell line) or Crandell feline kidney (CRFK) cells (a feline renal cell line). Efficiency of virus isolation was higher in MYA-1 cells than in CRFK cells. Interestingly, among the 17 cats from which FPV was isolated, 9 cats were positive for virus neutralizing (VN) antibody against FPV, indicating that FPV infected PBMCs and was not eliminated from PBMCs even in the presence of VN antibodies in the cats.     

A serosurvey of viral infections in lions (Panthera leo), from Queen Elizabeth National Park, Uganda

Serum samples from 14 lions (Panthera leo) from Queen Elizabeth National Park, Uganda, were collected during 1998 and 1999 to determine infectious disease exposure in this threatened population. Sera were analyzed for antibodies against feline immunodeficiency virus (FIV), feline calicivirus (FCV), feline herpesvirus 1 (feline rhinotracheitis: FHV1), feline/canine parvovirus (FPV/CPV), feline infectious peritonitis virus (feline coronavirus: FIPV), and canine distemper virus (CDV) or for the presence of feline leukemia virus (FeLV) antigens. Ten lions (71%) had antibodies against FIV, 11 (79%) had antibodies against CDV, 11 (79%) had antibodies against FCV, nine (64%) had antibodies against FHV1, and five (36%) had antibodies against FPV. Two of the 11 CDV-seropositive lions were subadults, indicating recent exposure of this population to CDV or a CDV-like virus. No lions had evidence of exposure to FeLV or FIPV. These results indicate that this endangered population has extensive exposure to common feline and canine viruses.     

Serosurvey of small carnivores in the Bolivian Chaco

Five species of Bolivian carnivores, including nine Geoffroy's cats (Oncifelis geoffroyi), ten ocelots (Leopardus pardalis), one jaguarundi (Herpailurus yaguarondi), nine pampas foxes (Pseudalopex gymnocercus), and five crab-eating foxes (Cerdocyon thous) were sampled between March 2001 and April 2005 and tested for antibodies to common pathogens of domestic carnivores. Carnivores were trapped in three areas: a village, the region between human settlements and a protected area, and within Kaa-Iya National Park, Bolivia. Antibodies to canine distemper virus were detected in ocelots and pampas foxes. Antibodies to canine parvovirus were detected in pampas foxes and crab-eating foxes. Geoffroy's cats and all of the ocelots tested positive for antibodies to feline calicivirus (FCV), while fewer than half of Geoffroy's cats and no ocelots had antibodies to feline panleukopenia (FPV). These results confirm that these species of Bolivian carnivores are not na?ve to common pathogens of domestic carnivores, and seropositive animals were found in villages as well as in the national park.     

Prevalence of seropositivity to pathogens in small carnivores in adjacent areas of Lazovskii Reserve

The prevalence of infectious diseases in wild and feral carnivores is poorly known in Primorsky Krai, where rare species such as the Amur tiger and the Far East leopard roam. In this study we evaluated the prevalence of seropositivity in feral (cats, dogs) and wild (raccoon dog, badger, American mink, Far Eastern wild cat) carnivores to various pathogens: distemper virus, parvovirus, feline immunodeficiency and feline leukemia virus, feline coronavirus, Toxoplasma gondii, Mycoplasma sp., and Chlamydia sp. It was shown that seropositivity occurred significantly more frequent in feral animals than in wild ones. The highest percentage of seropositive animals was observed in feral dogs. It is these diseases that can be dangerous for the Amur tiger and the Far East leopard, thus affecting their populations.     

Serological survey of the Iriomote cat (Felis iriomotensis) in Japan

The Iriomote cat (Felis iriomotensis) was first discovered on Iriomote Island in the Yaeyama Islands of Japan in 1965. Ten male and 11 female adult cats were captured during the 6 yr period from 1983 to 1988. These were examined for evidence of viral and mycoplasmal infections. Neither Mycoplasma sp. nor Ureaplasma sp. were detected in swab samples of oropharyngeal and urogenital regions. A foamy virus was isolated from the oropharyngeal swab of a female cat examined in 1988. Feline leukemia virus was not detected in any of the cats. All cats were negative for serum antibodies to feline panleukopenia virus, feline herpesvirus, feline immunodeficiency virus and rotavirus. Eleven of 19 (58%), 14 of 17 (82%) and 6 of 17 cats (35%) had serum antibodies against feline calicivirus, coronavirus and feline syncytium forming virus, respectively.     

从云豹分离的一株猫泛白细胞减少症病毒的特性

从病死的云豹体内分离到1株猫泛白细胞减少症病毒,进行了鉴定,研究了它的血凝特性和对猫与水貂的致病力,分析了它与猫泛白细胞减少症病毒参考毒株(FNF-8)抗原的相关性。 用中国兽药监察所提供的猫肾传代细胞(FK)进行病毒的分离鉴定。同步接种和异步接种测得病毒的TCID50均为4.8/ml。病毒经乙醚、酸(pH3.0)、热(56℃1小时)     

A serological survey of common feline pathogens in free-living European wildcats (<Emphasis Type="Italic">Felis silvestris</Emphasis>) in central Spain

Twenty-five serum samples of 22 free-living European wildcats (Felis silvestris) captured from 1991 to 1993 in central Spain were tested for evidence of exposure to seven feline pathogens. All the wildcats but one (95.4%) presented evidence of contact with at least one of the agents (mean = 2.2). Contact with feline leukemia virus (FeLV) was detected in 81% of the wildcats (antibodies, 77%; antigen p27, 15%). Antibodies to feline calicivirus (FCV, 80%), feline herpesvirus (FHV, 20%), feline parvovirus (FPV, 18%), and Chlamydophila sp. (27%) were also detected. Analyses were negative for feline immunodeficiency virus and feline coronavirus. The probability of having antibodies to FPV was inversely related with the concentration of serum cholesterol and with a morphometric index of body condition. Similarity in the composition of antibodies against disease agents (number and identity of detected and undetected antibodies) was significantly higher in pairs of female wildcats than in pairs of males or heterosexual pairs, suggesting that females had a more homogeneous exposure to pathogens. Seroprevalence for FHV was higher in males than in females. Antibodies to FHV and Chlamydophila sp. were more frequent in winter than in other seasons. In addition, the mean similarity of the pathogen community between pairs of serum samples was higher if both wildcats were caught during the same season than if they were not. Mean similarity was lowest when serum samples obtained in winter were compared with those from spring or summer. The results suggest that some agents probably had a reservoir in domestic cats and may cause some undetected morbidity/mortality in the studied wildcat population, whereas others, such as FeLV and FCV, may be enzootic.     

犬科、猫科动物细小病毒血清抗体调查

肉食兽细小病毒属于细小病毒科、细小病毒属中的一类病毒,能够感染多种动物,导致犬的出血性肠炎、幼龄犬的心肌炎、猫的白细胞减少、出血性肠炎、幼龄猫的共济失调症以及水貂的肠炎等多种疾病.血清学调查发现,由肉食兽细小病毒引起的疾病存在于世界各地.在我国,无论是家养还是野生动物均有细小病毒相关疫病的流行,对我国犬科和猫科动物的生存和健康构成巨大威胁(许树林等,1996;宋桂强等,2007).     

Enhancement of feline immunodeficiency virus infection after immunization with envelope glycoprotein subunit vaccines.

Cats were immunized three times with different recombinant feline immunodeficiency virus (FIV) candidate vaccines. Recombinant vaccinia virus (rVV)-expressed envelope glycoprotein with (vGR657) or without (vGR657 x 15) the cleavage site and an FIV envelope bacterial fusion protein (beta-Galactosidase-Env) were incorporated into immune-stimulating complexes or adjuvanted with Quil A. Although all immunized cats developed antibodies against the envelope protein, only the cats vaccinated with the rVV-expressed envelope glycoproteins developed antibodies which neutralized FIV infection of Crandell feline kidney cells. These antibodies failed to neutralize infection of thymocytes with a molecularly cloned homologous FIV. After the third immunization the cats were challenged with homologous FIV. Two weeks after challenge the cell-associated viral load proved to be significantly higher in the cats immunized with vGR657 and vGR657 x 15 than in the other cats. The cats immunized with vGR657 and vGR657 x 15 also developed antibodies against the Gag proteins more rapidly than the cats immunized with beta-Galactosidase-Env or the control cats. This suggested that immunization with rVV-expressed glycoprotein of FIV results in enhanced infectivity of FIV. It was shown that the observed enhancement could be transferred to naive cats with plasma collected at the day of challenge.     

Serological survey of feline leukemia virus infection and the outcome of antibody-positive cats

A serological survey was carried out to examine the presence of antibodies against feline leukemia virus (FeLV) and feline oncornavirus-associated cell membrane antigen (FOCMA) in 208 cat sera collected at Teikyo University School of Medicine. Seven cats (3.4%) were positive for FeLV antibodies by enzyme-linked immunosorbent assay whereas no cat was positive for FOCMA antibody by indirect membrane immunofluorescent test. Anemia, leukemia and/or lymphoma formation were not observed in these FeLV antibody-positive cats. But among these seven cats, three were positive for toxoplasma antibodies. One of them was also positive for Chlamydia psittaci antibody and it died in pneumonia. Among the four toxoplasma antibody negative cats, one was died in eosinophilic granuloma. Furthermore, two of three cats, which were used for experiments, had cold and took therapy.     

Evaluation of tri-combinant vaccine for feline herpesvirus, calicivirus and panleukopenia virus infections in Japanese native cats

Tri-combinant vaccine consisting of attenuated feline herpesvirus (FHV) and feline calicivirus (FCV) and inactivated feline panleukopenia virus (FPLV), were evaluated for safety and efficacy, using Japanese native cats and the viral strains isolated in Japan. Thirty-eight 9- to 12-week-old kittens were inoculated intramuscularly and subcutaneously with the vaccine. Consequently, no adverse reaction was found, and protective efficacy was confirmed by challenge tests with the virulent strains of each virus. Serum-neutralizing antibodies against FCV and FPLV were maintained for at least one year after vaccination, whereas antibody against FHV disappeared in two cases at 24 weeks after vaccination. Application of this vaccine seemed effective for control of feline viral disease in cats for experimental use.     

Survey of zona pellucida antigens for immunocontraception of cats

The purpose of this study was to screen a panel of native zona pellucida (ZP) antigens isolated from five mammalian species for immunocontraceptive activity in the cat (Felis catus). Native soluble-isolated ZP (SIZP) was prepared from the ovaries of cows (bZP), cats (fZP), ferrets (feZP), dogs (cZP), and mink (mZP). Vaccines were constructed using SIZP from each of the above species encapsulated in liposomes suspended in saline and emulsified with Freund's complete adjuvant (SpayVac). Female cats were immunized once (n = 3 cats per group). Serum was collected for determination of antibody titers against SIZP and for binding of antibodies to feline ovaries. All cats responded to immunization by producing anti-SIZP antibodies. The most immunogenic SIZP in cats was from mink, followed by feZP, cZP, and fZP in descending order. Antibodies had low reactivity for fZP, and no reactivity against feline ovaries was detected by immunohistochemistry. A breeding trial was commenced 20 weeks after immunization. All cats became pregnant, averaging 4.1 +/- 0.7 viable kittens per litter. We have previously shown that porcine SIZP is not an effective antigen for immunocontraception of cats. In this study, SIZP from five other mammalian species were immunogenic in the cat, but ZP antibodies failed to bind to fZP in situ, and fertility was not impeded.     

Passive antibody protection of cats against feline immunodeficiency virus infection.

All six cats passively immunized with sera from either feline immunodeficiency virus (FIV)-vaccinated cats or cats infected with FIV (Petaluma strain) were protected from homologous FIV infection at a challenge dose that infected all six control cats. Passive immunization with sera from cats vaccinated with uninfected allogeneic T cells used to grow the vaccine virus did not protect either of two cats against the same FIV challenge. These results suggest that antiviral humoral immunity, perhaps in synergy with anticellular antibodies, may be responsible for previously reported vaccine protection.     

Serologic and virologic surveys on feline herpesvirus and feline calicivirus infections in cats for experimental use

Serologic survey and virus isolation of feline herpesvirus (FHV) and feline calicivirus (FCV) were performed on cats used for research at the Laboratory Animal Research Centre, The University of Tsukuba, over the period from 1978 to 1981. Of the 507 mature and immature cats, 4 months old or older, 102 (20.1%) had HI antibody against FHV and 412 (81.3%) SN antibody against FCV. Some 23 (16.2%) and 76 (53.5%) kittens among 142 younger than 4 months had antibodies against FHV and FCV, respectively. Both the antibodies in kittens were considered to be maternally derived. The FCV antibody rate was especially high in cats weighing 2.5 kg (males) and 2.0 kg (females) or more, which were regarded as 8 to 10 months of age. An attempt was made to isolate the viruses from the oropharynx and conjunctiva of clinically healthy mature or immature cats and kittens. As the result, either one or both of the viruses were isolated from 31 of 75 mature and immature cats, and isolation rates of FHV and FCV were 6.7% and 36.0%, respectively. On the other hand, no virus was detectable in 16 kittens.     

Feline cytotoxic immune mechanisms against virus-associated leukemia and fibrosarcoma

Humoral and cellular cytotoxic immune mechanisms of cats were compared against feline leukemia virus (FeLV)- and feline sarcoma virus (FeSV)-transformed cells. The groups of animals studied were nonexposed control cats; FeLV-infected immune or viremic tumor-bearing cats; FeSV-inoculated tumor progressor or regressor cats, and cats immunized with FeSV-transformed autochthonous fibroblasts (ATF). Sera containing complement-dependent antibodies (CDA), which lysed FeLV-producer lymphoma lines, had no cytotoxic effects when tested against FeLV-producer FeSV-transformed fibroblasts. Sera with lytic CDA activity were also tested for antibody-dependent cellular cytotoxic (ADCC) effects with peripheral blood lymphocytes (PBL) from nonimmune cats. No ADCC activity was detected against either lymphoid or fibroblast target lines. To demonstrate that cat PBL contained ADCC effector cells, antibody-coated murine target cells were employed and positive results obtained. Natural killer (NK) assays were performed using PBL from normal and tumor-bearing cats. Cytotoxic effects were only detectable to FeLV-producer lymphomas, and comparable levels of NK activity were found in normal and lymphoid tumor-bearing animals. In cats immunized with ATF, a population of effector cells was found in peripheral blood which had functional characteristics of cytotoxic T lymphocytes (CTL). The killing of ATF by CTL-like cells was not inhibited by FeLV/FeSV immune sera or by sera from autochthonous immune cats. The comparative importance of humoral and cellular cytotoxic mechanisms against FeLV- and FeSV-induced tumors is discussed.     

Seroepidemiological investigation of feline chlamydiosis in cats and humans in Japan

The prevalence of chlamydia antibodies in Japan was investigated in 215 cat sera, consisting of 88 sera of stray cats and 127 sera of pet cats, and 2,184 human sera, taken from 2,003 general persons and 181 small animal clinic veterinarians, by microimmunofluorescence (MIF) testing with Chlamydia psittaci Fe/Pn1 of feline origin and Prk/6BC of avian origin as antigens. The prevalence rates of anti-Fe/Pn1 antibodies were 45.5% in stray cats, 17.3% in pet cats, 1.7% in general persons and 8.8% in small animal clinic veterinarians. The prevalence rates of anti-Prk/6BC antibodies were 51.1% in stray cats, 15.0% in pet cats, 3.1% in general persons and 5.0% in small animal clinic veterinarians. These results suggested that feline chlamydia infection is widely spread in cats especially in stray cats in Japan, and suggested that feline chlamydiosis could be transmitted to people who are in close contact with infected cats.     

Vaccination protects against in vivo-grown feline immunodeficiency virus even in the absence of detectable neutralizing antibodies.

So far, vaccination experiments against feline immunodeficiency virus have used in vitro-grown virus to challenge the vaccinated hosts. In this study, cats were vaccinated with fixed feline immunodeficiency virus-infected cells and challenged with plasma obtained from cats infected with the homologous virus diluted to contain 10 cat 50% infectious doses. As judged by virus culture, PCRs, and serological analyses performed over an 18-month period after the challenge, all of the vaccinated cats were clearly protected. Interestingly, prior to challenge most vaccines lacked antibodies capable of neutralizing a fresh isolate of the homologous virus.     

Epizootiologic investigations of selected infectious disease agents in free-ranging Eurasian lynx from Sweden

Serum samples from 106 Eurasian lynx (Lynx lynx) from across Sweden, found dead or shot by hunters in 1993-99, were investigated for presence of antibodies to feline parvovirus (FPV), feline coronavirus, feline calicivirus, feline herpesvirus, feline immunodeficiency virus, Francisella tularensis, and Anaplasma phagocytophila, and for feline leukemia virus antigen. In addition, tissue samples from 22 lynx submitted in 1999 were analyzed by real-time polymerase chain reaction (PCR) to detect nucleic acids specific for viral agents and A. phagocytophila. Except for FPV antibodies in one lynx and A. phagocytophila in four lynx, all serology was negative. All PCR results also were negative. It was concluded that free-ranging Swedish lynx do not have frequent contact with the infectious agents considered in this study.     

Canine and feline host ranges of canine parvovirus and feline panleukopenia virus: distinct host cell tropisms of each virus in vitro and in vivo.

Canine parvovirus (CPV) emerged as an apparently new virus during the mid-1970s. The origin of CPV is unknown, but a variation from feline panleukopenia virus (FPV) or another closely related parvovirus is suspected. Here we examine the in vitro and in vivo canine and feline host ranges of CPV and FPV. Examination of three canine and six feline cell lines and mitogen-stimulated canine and feline peripheral blood lymphocytes revealed that CPV replicates in both canine and feline cells, whereas FPV replicates efficiently only in feline cells. The in vivo host ranges were unexpectedly complex and distinct from the in vitro host ranges. Inoculation of dogs with FPV revealed efficient replication in the thymus and, to some degree, in the bone marrow, as shown by virus isolation, viral DNA recovery, and Southern blotting and by strand-specific in situ hybridization. FPV replication could not be demonstrated in mesenteric lymph nodes or in the small intestine, which are important target tissues in CPV infection. Although CPV replicated well in all the feline cells tested in vitro, it did not replicate in any tissue of cats after intramuscular or intravenous inoculation. These results indicate that these viruses have complex and overlapping host ranges and that distinct tissue tropisms exist in the homologous and heterologous hosts.     

犬细小病毒:从起源到进化

犬细小病毒(Canine parvovirus,CPV-2)首次分离于1978年,被认为是由遗传关系相近的猫泛白细胞减少症病毒(FPLV)或其他肉食兽细小病毒(FPLV-like virus)跨宿主感染犬产生的新病原.其感染能引起新生犬急性心肌炎或幼犬出血性肠炎,造成较高的发病率和死亡率.该病原爆发后短短一年时间内即广泛流行到世界各地.随着CPV-2对宿主的适应和变异,新抗原变异型(CPV-2a、CPV-2b和CPV-2e)不断产生并在世界各地逐步替代了CPV-2的流行.伴随CPV-2抗原变异的同时,其对宿主(犬、猫)嗜性、毒力等生物学特性也随之改变.本文综述了CPV-2过去30多年在世界流行和变异情况,并探讨了基因变异在病毒跨宿主传播中的意义.