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Feline coronavirus (FCoV) is divided into two types I and II, based on their growth in vitro and antigenicity. In this study, virus neutralization (VN) test was applied for type differentiation of FCoV infections. Sera of cats which were clinically and serologically diagnosed as feline infectious peritonitis (FIP) possessed significantly higher VN titers to type I FCoV, and sera from cats experimentally infected with FIPV type II had high VN titers to type II but not type I viruses. A total of 79 cat sera collected in the years between 2004 and 2005 were examined to evaluate seroprevalence by the VN test, showing the following results: (1) 50 cats (63.3%) were sero-positive to FCoV; (2) of the 50 FCoV positive cat serum samples, 49 (98%) showed significantly higher titers to type I virus and only one (2%) for type II virus. These results indicate that the VN test described here can be used for serological differentiation of FCoV infections of cats, and that FCoV type I is a dominant type in recent years of Japan. 相似文献
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Prevalence of feline coronavirus types I and II in cats with histopathologically verified feline infectious peritonitis 总被引：3，自引：0，他引：3
Benetka V Kübber-Heiss A Kolodziejek J Nowotny N Hofmann-Parisot M Möstl K 《Veterinary microbiology》2004,99(1):31-42
Feline coronaviruses (FCoV) vary widely in virulence causing a spectrum of clinical manifestations reaching from subclinical course to fatal feline infectious peritonitis (FIP). Independent of virulence variations they are separated into two different types, type I, the original FCoV, and type II, which is closely related to canine coronavirus (CCV). The prevalence of FCoV types in Austrian cat populations without FIP has been surveyed recently indicating that type I infections predominate. The distribution of FCoV types in cats, which had succumbed to FIP, however, was fairly unknown. PCR assays have been developed amplifying parts of the spike protein gene. Type-specific primer pairs were designed, generating PCR products of different sizes. A total of 94 organ pools of cats with histopathologically verified FIP was tested. A clear differentiation was achieved in 74 cats, 86% of them were type I positive, 7% type II positive, and 7% were positive for both types. These findings demonstrate that in FIP cases FCoV type I predominates, too, nonetheless, in 14% of the cases FCoV type II was detected, suggesting its causative involvement in cases of FIP. 相似文献
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Liesbeth Vogel Mariken Van der Lubben Eddie G. Te Lintelo Cornelis P.J. Bekker Tamara Geerts Leontine S. Schuijff Guy C.M. Grinwis Herman F. Egberink Peter J.M. Rottier 《Veterinary research》2010,41(5)
Feline coronaviruses (FCoV) comprise two biotypes: feline enteric coronaviruses (FECV) and feline infectious peritonitis viruses (FIPV). FECV is associated with asymptomatic persistent enteric infections, while FIPV causes feline infectious peritonitis (FIP), a usually fatal systemic disease in domestic cats and some wild Felidae. FIPV arises from FECV by mutation. FCoV also occur in two serotypes, I and II, of which the serotype I viruses are by far the most prevalent in the field. Yet, most of our knowledge about FCoV infections relates to serotype II viruses, particularly about the FIPV, mainly because type I viruses grow poorly in cell culture. Hence, the aim of the present work was the detailed study of the epidemiologically most relevant viruses, the avirulent serotype I viruses. Kittens were inoculated oronasally with different doses of two independent FECV field strains, UCD and RM. Persistent infection could be reproducibly established. The patterns of clinical symptoms, faecal virus shedding and seroconversion were monitored for up to 10 weeks revealing subtle but reproducible differences between the two viruses. Faecal virus, i.e. genomic RNA, was detected during persistent FECV infection only in the large intestine, downstream of the appendix, and could occasionally be observed also in the blood. The implications of our results, particularly our insights into the persistently infected state, are discussed. 相似文献
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Feline infectious peritonitis (FIP) is the most frequent lethal infectious disease in cats. However, understanding of FIP pathogenesis is still incomplete. Mutations in the ORF 3c/ORF 7b genes are proposed to play a role in the occurrence of the fatal FIPV biotype. Here, we investigated 282 tissue specimens from 28 cats that succumbed to FIP. Within one cat, viral sequences from different organs were similar or identical, whereas greater discrepancies were found comparing sequences from various cats. Eleven of the cats exhibited deletions in the 3c gene, resulting in truncated amino acid sequences. The 7b gene was affected by deletions only in one cat. In three of the FIP cats, coronavirus isolates with both intact 3c genes as well as 7b genes of full length could also be detected. Thus, deletions or stop codons in the 3c sequence seem to be a frequent but not compelling feature of FIPVs. 相似文献
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Brown MA 《Veterinary immunology and immunopathology》2011,143(3-4):265-268
Feline infectious peritonitis (FIP) is a fatal, immune-augmented, and progressive viral disease of cats associated with feline coronavirus (FCoV). Viral genetic determinants specifically associated with FIPV pathogenesis have not yet been discovered. Viral gene signatures in the spike, non-structural protein 3c, and membrane of the coronavirus genome have been shown to often correlate with disease manifestation. An "in vivo mutation transition hypothesis" is widely accepted and postulates that de novo virus mutation occurs in vivo giving rise to virulence. The existence of "distinct circulating avirulent and virulent strains" is an alternative hypothesis of viral pathogenesis. It may be possible that viral dynamics from both hypotheses are at play in the occurrence of FIP. Epidemiologic data suggests that the genetic background of the cat contributes to the manifestation of FIP. Further studies exploring both viral and host genetic determinants of disease in FIP offer specific opportunities for the management of this disease. 相似文献
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A closed household of 26 cats in which feline coronavirus (FCoV), feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) were endemic was observed for 10 years. Each cat was seropositive for FCoV on at least one occasion and the infection was maintained by reinfection. After 10 years, three of six surviving cats were still seropositive. Only one cat, which was also infected with FIV, developed feline infectious peritonitis (FIP). Rising anti-FCoV antibody titres did not indicate that the cat would develop FIP. The FeLV infection was self-limiting because all seven of the initially viraemic cats died within five years and the remainder were immune. However, FeLV had the greatest impact on mortality. Nine cats were initially FIV-positive and six more cats became infected during the course of the study, without evidence of having been bitten. The FIV infection did not adversely affect the cats' life expectancy. 相似文献
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A new monoclonal antibody (mAb), CCV2-2, was compared with the widely used FIPV3-70 mAb, both directed against canine coronavirus (CCoV), as a diagnostic and research tool. Western blot showed that both anti-CCoV mAbs only reacted with a protein of 50 kD, a weight consistent with the feline coronavirus (FCoV) viral nucleocapsid. A competitive inhibition enzyme-linked immunosorbent assay showed that the 2 recognized epitopes are distinct. Preincubation of CCV2-2 mAb with FCoV antigen suppressed the immunostaining. Formalin-fixed, paraffin-embedded sections from brains of 15 cats with the dry form of feline infectious peritonitis (FIP) were examined by immunohistochemistry. Immunohistochemistry was performed with both anti-CCoV mAbs, either on consecutive or on the same sections. A myeloid-histiocytic marker, MAC 387, was also used to identify FIP virus-infected cells. In all regions where MAC 387-positive cells were present, positive staining with the CCV2-2 mAb was systematically detected, except at some levels in 1 cat. In contrast, none or only a few cells were positive for the FIPV3-70 mAb. Double immunostaining showed macrophages that were immunopositive for either CCV2-2 alone or alternatively for CCV2-2 and FIPV3-70 mAbs. This reveals the coexistence of 2 cohorts of phagocytes whose FIP viral contents differed by the presence or absence of the FIPV3-70-recognized epitope. These findings provide evidence for antigenic heterogeneity in coronavirus nucleocapsid protein in FIP lesions, a result that is in line with molecular observations. In addition, we provide for the first time morphologic depiction of viral variants distribution in these lesions. 相似文献
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OBJECTIVES: i) To establish the seroprevalence of Feline Coronavirus (FCoV) infection in two defined groups of cats in Sydney: owned and feral cats; ii) to identify factors associated with an increased risk of infection with FCoV; and iii) to establish the seroprevalence and FCoV antibody titres of owned cats with immunohistochemically confirmed feline infectious peritonitis (FIP). DESIGN: Prospective multi-institutional cross sectional study. Procedure Serum samples from owned cats presented to three inner city veterinary clinics in Sydney and feral cats from a colony in South Western Sydney over an 11-month period were tested for FCoV antibodies using the Immunocomb test kit. The relationship between serological score and six major factors (breed, age, gender, number of cats per household, living environment and health status) in the owned cat sample population was analysed and compared to cats with FIR RESULTS: The seroprevalence of FCoV infection in the sample population of owned and feral cats was 34% and 0%, respectively. The median Immunocomb scores of DSH, Persian, Siamese and Devon Rex cats were significantly lower than that of Burmese, BSH, Abyssinian, Birman, Ragdoll and Russian Blue. The median lmmunocomb score of pedigree cats less than 2 years-of-age was significantly higher than for pedigree cats greater than 2 years-of-age. This distinction was not evident in DSH cats in these age groups. The number of cats per household at the time of blood collection had a strong positive association with Immunocomb score. The median Immunocomb score of cats with immunohistochemically confirmed FIP was significantly higher than cats in the sample population of owned cats but there was sufficient overlap between these two groups to make definitive diagnosis of FIP by serology impossible. CONCLUSION: This represents the first seroprevalence study of FCoV in Australia. The major determinants of antibody score of owned cats identified in this study were breed, age and the number of cats per household. The significant relationship between the breed of the cat and the FCoV antibody titre further supports the notion, proposed previously by the authors, that breed related differences exist in the immunological response to FCoV infection. 相似文献
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Evaluation of immunity to feline infectious peritonitis in cats with cutaneous viral-induced delayed hypersensitivity 总被引：1，自引：0，他引：1
Delayed-type hypersensitivity (DTH)-like reactions to feline infectious peritonitis (FIP) virus (FIPV) were induced in the skin of nine cats that were asymptomatic after a previous challenge-exposure with FIPV. Four of the nine previously challenge-exposed cats were negative for virus-neutralizing antibodies against FIPV at the time of intradermal (ID) testing for DTH. Two other cats tested for DTH when acutely ill with clinical FIP did not have cutaneous DTH responses to FIPV. Gross skin reactions to FIPV injected ID were observed in six of nine asymptomatic cats (67%) at postintradermal inoculation hours (PIH) 24, 48, and/or 72. The reactions consisted of focal, 1-5-mm to 2.5-cm diameter indurated or semi-firm, nonerythematous, slightly raised nodules. Microscopically, DTH-like reactions were observed in biopsies taken from the FIPV-inoculated skin of asymptomatic cats at PIH 24 to 72. The lesions consisted of perivascular and diffuse dermal infiltrations by macrophages, lymphocytes, and polymorphonuclear leukocytes (PMN). The dermal infiltrates, which were maximal at PIH 48 or 72, were predominantly mixed inflammatory cells (five of nine cats) or PMN (four of nine cats) at PIH 24, but later were predominantly mononuclear cells (six of nine cats) or mixed inflammatory cells (two of nine cats) at PIH 72. Five of nine cats (56%) with positive DTH skin responses had increased survival times after lethal ID challenge-exposure with FIPV compared to mean survival times in FIPV-naive, non-immune control cats that were DTH-negative when ID challenge-exposed. Four of nine DTH-positive cats (44%) resisted an ID challenge-exposure dose of FIPV that was fatal in both control cats, and two of the four remaining DTH-positive cats survived a third challenge-exposure with highly lethal doses of FIPV given intraperitoneally. Four of the six DTH-positive cats (67%) that died after re-challenge and were necropsied had lesions of noneffusive FIP, suggesting that cellular immunity may also be involved in the pathogenesis of noneffusive disease, whereas both control cats and both DTH-negative cats with clinical disease succumbed to effusive FIP. Seemingly, DTH responses to FIPV can be associated with an increased level of resistance to disease; however, this state of immunity is variable and apparently can be lost with time in some cats. 相似文献
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Two thousand, two hundred and seven cats from 14 shelters of a major UK cat charity were blood tested for feline coronavirus (FCoV) antibodies. Data was collated on breed, sex, age, number of cats at original location, outdoor access, health status, and time spent in the shelter prior to sampling (range 0 to 4 years). Some cats were also tested for feline leukaemia virus antigen, feline immunodeficiency virus, and Toxoplasma gondii antibodies. The effect of these variables on FCoV seropositivity was explored by multivariable logistic regression. FCoV seropositivity in cats that had spent 5 days or less in a shelter at sampling was significantly associated with a multi-cat origin, cats aged 3 years or less, and Persian breed. Whether pet, stray or feral, health status, indoor/outdoor access, and sex had no significant effect. Overall FCoV seropositivity was associated with time spent in a shelter but this association was not linear. Cats that had spent more than 60 days in a shelter were over five times as likely to be seropositive. This may be the result of a change in husbandry from solitary to communal housing for cats remaining in shelters long term. Rescue of cats for less than 60 days was not associated with a significant increasing risk of seropositivity. Significant variation existed in seropositivity between individual shelters overall and in cats rescued for less than 5 days. These findings may reflect inter-shelter variation in cat husbandry and variation in seropositivity of shelter intake respectively. 相似文献
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K Kai M Yukimune T Murata Y Uzuka M Kanoe H Matsumoto 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1992,54(3):501-507
Immunoperoxidase antibody (IPA) method as a titrating method of feline infectious peritonitis (FIP) virus (FIPV) was developed for titrating antibody to FIPV (IPA-titer). By this method the immune responses of the cats that had been infected with FIPV, were traced. The infected cats could be grouped into three types by their immune response to FIPV and clinical appearances. Type I cats lived for a long time, formed a major group among infected cats, had 160 to 1 x 10(4) IPA-titers, and showed healthy appearances without any changes both on autopsy and histopathologically. From among type I cats, type II cats appeared sporadically with rapid elevation of IPA titers to 3.2 x 10(5) and showing clinical signs of FIP, and died. Type III cats lived healthily for a long time with gradual elevation of IPA-titers to a plateau of about 1 x 10(5), then showed neuronal disorder of hind leg paralysis with the descending IPA-titers to 2 x 10(4), and died. Thus, typical FIP appeared as a hyper-immune disease. Other related problems are discussed. 相似文献
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Two cats previously challenge-exposed and seropositive to feline infectious peritonitis virus (FIPV) were evaluated for delayed-type hypersensitivity (DTH) skin responses to intradermal FIPV. Before testing, cat 1 (FIP-resistant) had survived a severe experimental FIPV challenge-exposure and had remained asymptomatic, whereas cat 2 (FIP-susceptible) developed acute fulminant FIP after a considerably smaller virus challenge-exposure. Cat 1 developed a focal thickened plaque at the FIPV-injected skin site at 48 hours after injection. Histological examinations of serial punch biopsies from virus-inoculated skin revealed perivascular and diffuse dermal infiltrations of macrophages, lymphocytes and polymorphonuclear leucocytes which were maximal at 48 to 72 hours after injection. In contrast, cat 2 did not react grossly and showed only very mild dermal infiltrates at 72 hours after injection. The present findings of strong DTH responses to FIPV in a resistant cat and minimal responses in a cat with acute fulminant FIP suggest that certain in vivo cellular immune reactions may be associated with disease resistance. 相似文献
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Feline infectious peritonitis (FIP), caused by feline coronavirus (FCoV) infection, is a highly lethal disease without effective therapy and prevention. With an immune-mediated disease entity, host genetic variant was suggested to influence the occurrence of FIP. This study aimed at evaluating cytokine-associated single nucleotide polymorphisms (SNPs), i.e., tumor necrosis factor alpha (TNF-α), receptor-associated SNPs, i.e., C-type lectin DC-SIGN (CD209), and the five FIP-associated SNPs identified from Birman cats of USA and Denmark origins and their associations with the outcome of FCoV infection in 71 FIP cats and 93 FCoV infected non-FIP cats in a genetically more diverse cat populations. A promoter variant, fTNFA - 421 T, was found to be a disease-resistance allele. One SNP was identified in the extracellular domain (ECD) of fCD209 at position +1900, a G to A substitution, and the A allele was associated with FIP susceptibility. Three SNPs located in the introns of fCD209, at positions +2276, +2392, and +2713, were identified to be associated with the outcome of FCoV infection, with statistical relevance. In contrast, among the five Birman FIP cat-associated SNPs, no genotype or allele showed significant differences between our FIP and non-FIP groups. As disease resistance is multifactorial and several other host genes could involve in the development of FIP, the five genetic traits identified in this study should facilitate in the future breeding of the disease-resistant animal to reduce the occurrence of cats succumbing to FIP.
Electronic supplementary material
The online version of this article (doi:10.1186/s13567-014-0123-6) contains supplementary material, which is available to authorized users. 相似文献18.
Addie DD McDonald M Audhuy S Burr P Hollins J Kovacic R Lutz H Luxton Z Mazar S Meli ML 《Journal of Feline Medicine and Surgery》2012,14(2):171-176
Feline coronavirus (FCoV) causes feline infectious peritonitis (FIP). Since 2002, when 20 cats on the Falkland Islands were found to be FCoV seronegative, only seronegative cats could be imported. Between 2005-2007, 95 pet and 10 feral cats tested negative by indirect immunofluorescence antibody (IFA) analysis using two strains of type II FCoV, two transmissible gastroenteritis virus assays, an enzyme-linked immunosorbent assay and rapid immunomigration test. Twenty-four samples (23%) showed non-specific fluorescence, mostly attributable to anti-nuclear antibodies (ANA). The reason for ANA was unclear: reactive samples were negative for Erhlichia canis antibodies; seven were feline immunodeficiency virus positive, but 15 were negative. It was not possible to determine retrospectively whether the cats had autoimmune disease, hyperthyroidism treatment, or recent vaccination which may also cause ANA. The FCoV/ FIP-free status of the Falkland Islands cats should be maintained by FCoV testing incoming cats. However, ANA can complicate interpretation of IFA tests. 相似文献
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Addie DD Kennedy LJ Ryvar R Willoughby K Gaskell RM Ollier WE Nart P Radford AD 《Journal of Feline Medicine and Surgery》2004,6(2):59-62
There are four outcomes to feline coronavirus (FCoV) infection: the development of feline infectious peritonitis (FIP, which is immune-mediated), subclinical infection, development of healthy lifelong carriers and a small minority of cats who resist infection (Addie and Jarrett, Veterinary Record 148 (2001) 649). Examination of the FCoV genome has shown that the same strain of virus can produce different clinical manifestations, suggesting that host genetic factors may also play a role in the outcome of infection. FIP is most prevalent amongst pedigree cats, although how much of this is due to them living in large groups (leading to higher virus challenge and stress which predisposes to FIP) and how much is due to genetic susceptibility is not known. If host genetics could be shown to play a role in disease, it may allow the detection of cats with a susceptibility to FIP and the development of increased population resistance through selective breeding. The feline leucocyte antigen (FLA) complex contains many genes that are central to the control of the immune response. In this preliminary study, we used clonal sequence analysis or reference strand conformational analysis (RSCA) to analyse the class II FLA-DRB of 25 cats for which the outcome of FCoV exposure was known. Individual cats were shown to have between two and six FLA-DRB alleles. There was no statistically significant association between the number of alleles and the outcome of FCoV infection. No particular allele appeared to be associated with either the development of FIP, resistance to FCoV, or the carrier status. However, the analysis was complicated by apparent breed variation in FLA-DRB and the small number of individuals in this study. 相似文献