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Curtis BE, Abdo Z, Graham B, LaVoy A, Evans SJM, Santangelo K, Dean GA. An Aptamer-Based Proteomic Analysis of Plasma from Cats ( Felis catus) with Clinical Feline Infectious Peritonitis. Viruses 2024; 16:141. [PMID: 38257841 PMCID: PMC10819688 DOI: 10.3390/v16010141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/13/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
Feline infectious peritonitis (FIP) is a systemic disease manifestation of feline coronavirus (FCoV) and is the most important cause of infectious disease-related deaths in domestic cats. FIP has a variable clinical manifestation but is most often characterized by widespread vasculitis with visceral involvement and/or neurological disease that is typically fatal in the absence of antiviral therapy. Using an aptamer-based proteomics assay, we analyzed the plasma protein profiles of cats who were naturally infected with FIP (n = 19) in comparison to the plasma protein profiles of cats who were clinically healthy and negative for FCoV (n = 17) and cats who were positive for the enteric form of FCoV (n = 9). We identified 442 proteins that were significantly differentiable; in total, 219 increased and 223 decreased in FIP plasma versus clinically healthy cat plasma. Pathway enrichment and associated analyses showed that differentiable proteins were related to immune system processes, including the innate immune response, cytokine signaling, and antigen presentation, as well as apoptosis and vascular integrity. The relevance of these findings is discussed in the context of previous studies. While these results have the potential to inform diagnostic, therapeutic, and preventative investigations, they represent only a first step, and will require further validation.
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Affiliation(s)
| | | | | | | | | | | | - Gregg A. Dean
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA; (B.E.C.); (A.L.); (S.J.M.E.); (K.S.)
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2
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Zhu J, Deng S, Mou D, Zhang G, Fu Y, Huang W, Zhang Y, Lyu Y. Analysis of spike and accessory 3c genes mutations of less virulent and FIP-associated feline coronaviruses in Beijing, China. Virology 2024; 589:109919. [PMID: 37939649 DOI: 10.1016/j.virol.2023.109919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 10/13/2023] [Accepted: 10/20/2023] [Indexed: 11/10/2023]
Abstract
Mutations in S and 3c genes of feline coronavirus (FCoV) have been associated with the development of feline infectious peritonitis (FIP). In the present study, FCoV S and 3c genes mutations were analyzed in healthy and FIP cats. M1058L mutation was found in 13.64% (3/22) feces from FIP cats, but not in feces from healthy cats (0/39). The intact 3c gene was found in feces from both healthy cats (19/19) and FIP cats (12/12). All parenteral samples from FIP cats carried one or more of the M1058L mutation, S1060A mutation and mutated 3c gene. FCoV reverse-transcriptase polymerase chain reaction (RT-PCR) of parenteral samples (including ascites, pleural effusions and tissue) is recommended as the gold standard for clinical diagnosis of FIP rather than detection of the M1058L mutation, but when cats have severe gastrointestinal symptoms and lesions, detection of the M1058L mutation in feces may be helpful in diagnosing FIP.
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Affiliation(s)
- Jingru Zhu
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Shuqi Deng
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Danxia Mou
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Gege Zhang
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Yingying Fu
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Wei Huang
- China Agricultural University Veterinary Teaching Hospital, Beijing, 100193, China
| | - Yueping Zhang
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Yanli Lyu
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China; China Agricultural University Veterinary Teaching Hospital, Beijing, 100193, China.
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3
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Tasker S, Addie DD, Egberink H, Hofmann-Lehmann R, Hosie MJ, Truyen U, Belák S, Boucraut-Baralon C, Frymus T, Lloret A, Marsilio F, Pennisi MG, Thiry E, Möstl K, Hartmann K. Feline Infectious Peritonitis: European Advisory Board on Cat Diseases Guidelines. Viruses 2023; 15:1847. [PMID: 37766254 PMCID: PMC10535984 DOI: 10.3390/v15091847] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/19/2023] [Accepted: 08/23/2023] [Indexed: 09/29/2023] Open
Abstract
Feline coronavirus (FCoV) is a ubiquitous RNA virus of cats, which is transmitted faeco-orally. In these guidelines, the European Advisory Board on Cat Diseases (ABCD) presents a comprehensive review of feline infectious peritonitis (FIP). FCoV is primarily an enteric virus and most infections do not cause clinical signs, or result in only enteritis, but a small proportion of FCoV-infected cats develop FIP. The pathology in FIP comprises a perivascular phlebitis that can affect any organ. Cats under two years old are most frequently affected by FIP. Most cats present with fever, anorexia, and weight loss; many have effusions, and some have ocular and/or neurological signs. Making a diagnosis is complex and ABCD FIP Diagnostic Approach Tools are available to aid veterinarians. Sampling an effusion, when present, for cytology, biochemistry, and FCoV RNA or FCoV antigen detection is very useful diagnostically. In the absence of an effusion, fine-needle aspirates from affected organs for cytology and FCoV RNA or FCoV antigen detection are helpful. Definitive diagnosis usually requires histopathology with FCoV antigen detection. Antiviral treatments now enable recovery in many cases from this previously fatal disease; nucleoside analogues (e.g., oral GS-441524) are very effective, although they are not available in all countries.
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Affiliation(s)
- Séverine Tasker
- Bristol Veterinary School, University of Bristol, Bristol BS40 5DU, UK
- Linnaeus Veterinary Limited, Shirley, Solihull B90 4BN, UK
| | - Diane D. Addie
- Independent Researcher, 64000 Pyrénées Aquitaine, France;
| | - Herman Egberink
- Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, University of Utrecht, 3584 CL Utrecht, The Netherlands;
| | - Regina Hofmann-Lehmann
- Clinical Laboratory, Department of Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland;
| | - Margaret J. Hosie
- MRC-University of Glasgow Centre for Virus Research, Garscube Estate, Glasgow G61 1QH, UK;
| | - Uwe Truyen
- Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, 04103 Leipzig, Germany;
| | - Sándor Belák
- Department of Biomedical Sciences and Veterinary Public Health (BVF), Swedish University of Agricultural Sciences (SLU), P.O. Box 7036, 750 07 Uppsala, Sweden;
| | | | - Tadeusz Frymus
- Department of Small Animal Diseases with Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, 02-787 Warsaw, Poland;
| | - Albert Lloret
- Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain;
| | - Fulvio Marsilio
- Faculty of Veterinary Medicine, Università Degli Studi di Teramo, 64100 Teramo, Italy;
| | - Maria Grazia Pennisi
- Dipartimento di Scienze Veterinarie, Università di Messina, 98168 Messina, Italy;
| | - Etienne Thiry
- Veterinary Virology and Animal Viral Diseases, Department of Infectious and Parasitic Diseases, FARAH Research Centre, Faculty of Veterinary Medicine, Liège University, B-4000 Liège, Belgium;
| | - Karin Möstl
- Institute of Virology, Department for Pathobiology, University of Veterinary Medicine, 1210 Vienna, Austria;
| | - Katrin Hartmann
- LMU Small Animal Clinic, Centre for Clinical Veterinary Medicine, LMU Munich, 80539 Munich, Germany;
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Zehr JD, Kosakovsky Pond SL, Millet JK, Olarte-Castillo XA, Lucaci AG, Shank SD, Ceres KM, Choi A, Whittaker GR, Goodman LB, Stanhope MJ. Natural selection differences detected in key protein domains between non-pathogenic and pathogenic feline coronavirus phenotypes. Virus Evol 2023; 9:vead019. [PMID: 37038392 PMCID: PMC10082545 DOI: 10.1093/ve/vead019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/14/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
Feline coronaviruses (FCoVs) commonly cause mild enteric infections in felines worldwide (termed feline enteric coronavirus [FECV]), with around 12 per cent developing into deadly feline infectious peritonitis (FIP; feline infectious peritonitis virus [FIPV]). Genomic differences between FECV and FIPV have been reported, yet the putative genotypic basis of the highly pathogenic phenotype remains unclear. Here, we used state-of-the-art molecular evolutionary genetic statistical techniques to identify and compare differences in natural selection pressure between FECV and FIPV sequences, as well as to identify FIPV- and FECV-specific signals of positive selection. We analyzed full-length FCoV protein coding genes thought to contain mutations associated with FIPV (Spike, ORF3abc, and ORF7ab). We identified two sites exhibiting differences in natural selection pressure between FECV and FIPV: one within the S1/S2 furin cleavage site (FCS) and the other within the fusion domain of Spike. We also found fifteen sites subject to positive selection associated with FIPV within Spike, eleven of which have not previously been suggested as possibly relevant to FIP development. These sites fall within Spike protein subdomains that participate in host cell receptor interaction, immune evasion, tropism shifts, host cellular entry, and viral escape. There were fourteen sites (twelve novel sites) within Spike under positive selection associated with the FECV phenotype, almost exclusively within the S1/S2 FCS and adjacent to C domain, along with a signal of relaxed selection in FIPV relative to FECV, suggesting that furin cleavage functionality may not be needed for FIPV. Positive selection inferred in ORF7b was associated with the FECV phenotype and included twenty-four positively selected sites, while ORF7b had signals of relaxed selection in FIPV. We found evidence of positive selection in ORF3c in FCoV-wide analyses, but no specific association with the FIPV or FECV phenotype. We hypothesize that some combination of mutations in FECV may contribute to FIP development, and that it is unlikely to be one singular 'switch' mutational event. This work expands our understanding of the complexities of FIP development and provides insights into how evolutionary forces may alter pathogenesis in coronavirus genomes.
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Affiliation(s)
- Jordan D Zehr
- Department of Biology, Temple University, Institute for Genomics and Evolutionary Medicine, Philadelphia, PA 19122, USA
| | - Sergei L Kosakovsky Pond
- Department of Biology, Temple University, Institute for Genomics and Evolutionary Medicine, Philadelphia, PA 19122, USA
| | - Jean K Millet
- Université Paris-Saclay, INRAE, UVSQ, Virologie et Immunologie Moléculaires, Jouy-en-Josas 78352, France
| | - Ximena A Olarte-Castillo
- Department of Microbiology & Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
- James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Alexander G Lucaci
- Department of Biology, Temple University, Institute for Genomics and Evolutionary Medicine, Philadelphia, PA 19122, USA
| | - Stephen D Shank
- Department of Biology, Temple University, Institute for Genomics and Evolutionary Medicine, Philadelphia, PA 19122, USA
| | - Kristina M Ceres
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Annette Choi
- Department of Microbiology & Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Gary R Whittaker
- Department of Microbiology & Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Laura B Goodman
- James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Michael J Stanhope
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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5
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Zehr JD, Pond SLK, Millet JK, Olarte-Castillo XA, Lucaci AG, Shank SD, Ceres KM, Choi A, Whittaker GR, Goodman LB, Stanhope MJ. Natural selection differences detected in key protein domains between non-pathogenic and pathogenic Feline Coronavirus phenotypes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.11.523607. [PMID: 36712007 PMCID: PMC9882035 DOI: 10.1101/2023.01.11.523607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Feline Coronaviruses (FCoVs) commonly cause mild enteric infections in felines worldwide (termed Feline Enteric Coronavirus [FECV]), with around 12% developing into deadly Feline Infectious Peritonitis (FIP; Feline Infectious Peritonitis Virus [FIPV]). Genomic differences between FECV and FIPV have been reported, yet the putative genotypic basis of the highly pathogenic phenotype remains unclear. Here, we used state-of-the-art molecular evolutionary genetic statistical techniques to identify and compare differences in natural selection pressure between FECV and FIPV sequences, as well as to identify FIPV and FECV specific signals of positive selection. We analyzed full length FCoV protein coding genes thought to contain mutations associated with FIPV (Spike, ORF3abc, and ORF7ab). We identified two sites exhibiting differences in natural selection pressure between FECV and FIPV: one within the S1/S2 furin cleavage site, and the other within the fusion domain of Spike. We also found 15 sites subject to positive selection associated with FIPV within Spike, 11 of which have not previously been suggested as possibly relevant to FIP development. These sites fall within Spike protein subdomains that participate in host cell receptor interaction, immune evasion, tropism shifts, host cellular entry, and viral escape. There were 14 sites (12 novel) within Spike under positive selection associated with the FECV phenotype, almost exclusively within the S1/S2 furin cleavage site and adjacent C domain, along with a signal of relaxed selection in FIPV relative to FECV, suggesting that furin cleavage functionality may not be needed for FIPV. Positive selection inferred in ORF7b was associated with the FECV phenotype, and included 24 positively selected sites, while ORF7b had signals of relaxed selection in FIPV. We found evidence of positive selection in ORF3c in FCoV wide analyses, but no specific association with the FIPV or FECV phenotype. We hypothesize that some combination of mutations in FECV may contribute to FIP development, and that is unlikely to be one singular "switch" mutational event. This work expands our understanding of the complexities of FIP development and provides insights into how evolutionary forces may alter pathogenesis in coronavirus genomes.
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Affiliation(s)
- Jordan D. Zehr
- Department of Biology, Temple University, Institute for Genomics and Evolutionary Medicine, Philadelphia, PA 19122, USA
| | - Sergei L. Kosakovsky Pond
- Department of Biology, Temple University, Institute for Genomics and Evolutionary Medicine, Philadelphia, PA 19122, USA
| | - Jean K. Millet
- Université Paris-Saclay, INRAE, UVSQ, Virologie et Immunologie Moléculaires, 78352 Jouyen-Josas, France
| | - Ximena A. Olarte-Castillo
- Department of Microbiology & Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- James A. Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, Ithaca, NY, 14853, USA
| | - Alexander G. Lucaci
- Department of Biology, Temple University, Institute for Genomics and Evolutionary Medicine, Philadelphia, PA 19122, USA
| | - Stephen D. Shank
- Department of Biology, Temple University, Institute for Genomics and Evolutionary Medicine, Philadelphia, PA 19122, USA
| | - Kristina M. Ceres
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Annette Choi
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Department of Microbiology & Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Gary R. Whittaker
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Department of Microbiology & Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Laura B. Goodman
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- James A. Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, Ithaca, NY, 14853, USA
| | - Michael J. Stanhope
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
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Detection of Feline Coronavirus Variants in Cats without Feline Infectious Peritonitis. Viruses 2022; 14:v14081671. [PMID: 36016293 PMCID: PMC9412601 DOI: 10.3390/v14081671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
(1) Background: This study aimed to detect feline coronavirus (FCoV) and characterize spike (S) gene mutation profiles in cats suffering from diseases other than feline infectious peritonitis (FIP) using commercial real-time reverse transcription polymerase chain reaction (RT-qPCR) and reevaluating results by sequencing. (2) Methods: In 87 cats in which FIP was excluded by histopathology and immunohistochemistry, FCoV 7b gene and S gene mutation RT-qPCR was performed prospectively on incisional biopsies and fine-needle aspirates of different organs, body fluids, and feces. Samples positive for S gene mutations or mixed FCoV underwent sequencing. (3) Results: In 21/87 cats, FCoV RNA was detectable. S gene mutations were detected by commercial RT-qPCR (and a diagnostic algorithm that was used at the time of sample submission) in at least one sample in 14/21 cats (66.7%), with only mutated FCoV in 2/21, only mixed in 1/21, and different results in 11/21 cats; in the remaining 7/21 cats, RNA load was too low to differentiate. However, sequencing of 8 tissue samples and 8 fecal samples of 9 cats did not confirm mutated FCoV in any of the FCoV RNA-positive cats without FIP. (4) Conclusions: Sequencing results did not confirm results of the commercial S gene mutation RT-qPCR.
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Role of Feline Coronavirus as Contributor to Diarrhea in Cats from Breeding Catteries. Viruses 2022; 14:v14050858. [PMID: 35632600 PMCID: PMC9143444 DOI: 10.3390/v14050858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/13/2022] [Accepted: 04/17/2022] [Indexed: 01/17/2023] Open
Abstract
(1) Background: Feline coronavirus infection (FCoV) is common in multi-cat environments. A role of FCoV in causing diarrhea is often assumed, but has not been proven. The aim of this study was to evaluate an association of FCoV infection with diarrhea in multi-cat environments. (2) Methods: The study included 234 cats from 37 catteries. Fecal samples were analyzed for FCoV RNA by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Potential co-infections were determined by applying a qPCR panel on different potential enteropathogens and fecal flotation. A fecal scoring system was used to categorize feces as diarrheic or non-diarrheic. (3) Results: Of the 234 cats included, 23 had diarrhea. The prevalence of FCoV infection was 87.0% in cats with and 58.8% in cats without diarrhea. FCoV infection was significantly associated with diarrhea (Odds Ratio (OR) 5.01; p = 0.008). In addition, presence of Clostridium perfringens α toxin (OR 6.93; p = 0.032) and feline panleukopenia virus (OR 13.74; p = 0.004) were associated with an increased risk of diarrhea. There was no correlation between FCoV load and fecal score. FCoV-positive cats with co-infections were not more likely to have diarrhea than FCoV-positive cats without co-infections (p = 0.455). (4) Conclusions: FCoV infection is common in cats from catteries and can be associated with diarrhea.
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The Effect of Natural Feline Coronavirus Infection on the Host Immune Response: A Whole-Transcriptome Analysis of the Mesenteric Lymph Nodes in Cats with and without Feline Infectious Peritonitis. Pathogens 2020; 9:pathogens9070524. [PMID: 32610501 PMCID: PMC7400348 DOI: 10.3390/pathogens9070524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022] Open
Abstract
Feline infectious peritonitis (FIP) is a coronavirus-induced disease of cats, in which the immune system is known to play a crucial, but complex, role in the pathogenesis. This role is still incompletely understood, with involvement of both host and viral factors. To evaluate differential gene expression and pathway involvement in feline coronavirus (FCoV) infection and FIP, we applied next-generation RNA-sequencing of the mesenteric lymph nodes from cats with naturally-acquired FIP, as well as those with systemic FCoV infection without FIP, and those with neither. Viral infection was associated with upregulation of viral defenses regardless of the disease state, but to a greater degree in FIP. FIP was associated with higher pro-inflammatory pathway enrichment, whilst non-FIP FCoV-positive cats showed lower enrichment of humoral immunity pathways, below that of uninfected cats in the case of immunoglobulin production pathways. This host response is presumed to be protective. In FIP, downregulation of T cell-related processes was observed, which did not occur in non-FIP FCoV-positive cats. These results emphasize the importance of the host’s immune balance in determining the outcome of the FCoV infection.
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Kennedy MA. Feline Infectious Peritonitis: Update on Pathogenesis, Diagnostics, and Treatment. Vet Clin North Am Small Anim Pract 2020; 50:1001-1011. [PMID: 32563530 DOI: 10.1016/j.cvsm.2020.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Feline infectious peritonitis (FIP) is a mysterious and lethal disease of cats. The causative agent, feline coronavirus (FCoV), is ubiquitous in most feline populations, yet the disease is sporadic in nature. Mutations in the infecting virus combined with an inappropriate immune response to the FCoV contribute to the development of FIP. Diagnosis can be challenging because signs may be vague, clinical pathology parameters are nonspecific, and the gold standard for diagnosis is invasive: histopathology of affected tissue. This article discusses the developments in the understanding of this disease as well as the progress in diagnosis and treatment.
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Affiliation(s)
- Melissa A Kennedy
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Room A205 VMC, 2407 River Drive, Knoxville, TN 37996-4543, USA.
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Felten S, Hartmann K. Diagnosis of Feline Infectious Peritonitis: A Review of the Current Literature. Viruses 2019; 11:v11111068. [PMID: 31731711 PMCID: PMC6893704 DOI: 10.3390/v11111068] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/10/2019] [Accepted: 11/13/2019] [Indexed: 12/12/2022] Open
Abstract
Feline infectious peritonitis (FIP) is a fatal disease that poses several challenges for veterinarians: clinical signs and laboratory changes are non-specific, and there are two pathotypes of the etiologic agent feline coronavirus (FCoV), sometimes referred to as feline enteric coronavirus (FECV) and feline infectious peritonitis virus (FIPV) that vary fundamentally in their virulence, but are indistinguishable by a number of diagnostic methods. This review focuses on all important steps every veterinary practitioner has to deal with and new diagnostic tests that can be considered when encountering a cat with suspected FIP with the aim to establish a definitive diagnosis. It gives an overview on all available direct and indirect diagnostic tests and their sensitivity and specificity reported in the literature in different sample material. By providing summarized data for sensitivity and specificity of each diagnostic test and each sample material, which can easily be accessed in tables, this review can help to facilitate the interpretation of different diagnostic tests and raise awareness of their advantages and limitations. Additionally, diagnostic trees depict recommended diagnostic steps that should be performed in cats suspected of having FIP based on their clinical signs or clinicopathologic abnormalities. These steps can easily be followed in clinical practice.
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Emmler L, Felten S, Matiasek K, Balzer HJ, Pantchev N, Leutenegger C, Hartmann K. Feline coronavirus with and without spike gene mutations detected by real-time RT-PCRs in cats with feline infectious peritonitis. J Feline Med Surg 2019; 22:791-799. [PMID: 31729897 PMCID: PMC7206566 DOI: 10.1177/1098612x19886671] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Feline infectious peritonitis (FIP) emerges when feline coronaviruses (FCoVs) mutate within their host to a highly virulent biotype and the immune response is not able to control the infection. FCoV spike (S) gene mutations are considered to contribute to the change in virulence by enabling FCoV infection of and replication in macrophages. This study investigated the presence of FCoV with and without S gene mutations in cats with FIP using two different real-time RT-PCRs on different samples obtained under clinical conditions. METHODS Fine-needle aspirates (FNAs) and incisional biopsies (IBs) of popliteal and mesenteric lymph nodes, liver, spleen, omentum and kidneys (each n = 20), EDTA blood (n = 13), buffy coat smears (n = 13), serum (n = 11), effusion (n = 14), cerebrospinal fluid (n = 16), aqueous humour (n = 20) and peritoneal lavage (n = 6) were obtained from 20 cats with FIP diagnosed by immunohistochemistry. Samples were examined by RT-PCR targeting the FCoV 7b gene, detecting all FCoV, and S gene mutation RT-PCR targeting mutations in nucleotides 23531 and 23537. The prevalence of FCoV detected in each sample type was calculated. RESULTS In 20/20 cats, FCoV with S gene mutations was present in at least one sample, but there was variation in which sample was positive. FCoV with mutations in the S gene was most frequently found in effusion (64%, 95% confidence interval [CI] 39-89), followed by spleen, omentum and kidney IBs (50%, 95% CI 28-72), mesenteric lymph node IBs and FNAs (45%, 95% CI 23-67), and FNAs of spleen and liver and liver IBs (40%, 95% CI 19-62). CONCLUSIONS AND RELEVANCE In these 20 cats with FIP, FCoVs with S gene mutations were found in every cat in at least one tissue or fluid sample. This highlights the association between mutated S gene and systemic FCoV spread. Examining a combination of different samples increased the probability of finding FCoV with the mutated S gene.
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Affiliation(s)
- Laura Emmler
- Clinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Sandra Felten
- Clinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | - Kaspar Matiasek
- Section of Clinical and Comparative Neuropathology, Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, Ludwig Maximilian University of Munich, Munich, Germany
| | | | | | | | - Katrin Hartmann
- Clinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, Ludwig Maximilian University of Munich, Munich, Germany
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Sangl L, Matiasek K, Felten S, Gründl S, Bergmann M, Balzer HJ, Pantchev N, Leutenegger CM, Hartmann K. Detection of feline coronavirus mutations in paraffin-embedded tissues in cats with feline infectious peritonitis and controls. J Feline Med Surg 2019; 21:133-142. [PMID: 29542369 PMCID: PMC10814605 DOI: 10.1177/1098612x18762883] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The amino acid substitutions M1058L and S1060A in the spike protein of feline coronavirus (FCoV) have been postulated to be responsible for the development of the pathogenic feline infectious peritonitis virus (FIPV), which causes feline infectious peritonitis (FIP). The aim of the following study was to investigate the presence of mutated virus in tissue samples of cats with and without FIP. METHODS The study population consisted of 64 cats, 34 of which were diagnosed with FIP and 30 control cats. All cases underwent autopsy, histopathology and immunohistochemistry (IHC) for FCoV. Furthermore, a genotype-discriminating quantitative reverse transcriptase PCR (RT-qPCR) was performed on shavings of paraffin-embedded tissues to discriminate between cats with FIP and controls, and the sensitivity and specificity of this discriminating RT-qPCR were calculated using 95% confidence intervals (CIs). RESULTS Specificity of genotype-discriminating RT-qPCR was 100.0% (95% CI 88.4-100.0), and sensitivity was 70.6% (95% CI 52.5-84.9). In cats with FIP, 24/34 tested positive for FIPV. In samples of three control cats and in seven cats with FIP, FCoV was found, but genotyping was not possible owing to low FCoV RNA concentrations. Out of the positive samples, 23 showed the amino acid substitution M1058L in the spike protein and none the substitution S1060A. One sample in a cat with FIP revealed a mixed population of non-mutated FCoV and FIPV (mixed genotype). For one sample genotyping was not possible despite high viral load, and two samples were negative for FCoV. CONCLUSIONS AND RELEVANCE As none of the control animals showed FCoV amino acid substitutions previously demonstrated in cats with FIP, it can be presumed that the substitution M1058L correlates with the presence of FIP. FCoV was detected in low concentration in tissues of control animals, confirming the ability of FCoV to spread systemically. The fact that no negative controls were included in the IHC protocol could potentially lead to an underestimation of the sensitivity of the RT-qPCR.
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Affiliation(s)
- Laura Sangl
- Clinic of Small Animal Medicine, LMU, Munich, Germany
| | - Kaspar Matiasek
- Section of Clinical and Comparative Neuropathology, Centre for Clinical Veterinary Medicine, LMU, Munich, Germany
| | - Sandra Felten
- Clinic of Small Animal Medicine, LMU, Munich, Germany
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13
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Mészáros I, Olasz F, Kádár-Hürkecz E, Bálint Á, Hornyák Á, Belák S, Zádori Z. Cellular localisation of the proteins of region 3 of feline enteric coronavirus. Acta Vet Hung 2018; 66:493-508. [PMID: 30264619 DOI: 10.1556/004.2018.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Feline enteric coronaviruses have three open reading frames (ORFs) in region 3 (3a, 3b, and 3c). All three ORFs were expressed with C-terminal eGFP and 3xFLAG tags in different cell lines and their localisation was determined. ORF 3a is predicted to contain DNA-binding and transcription activator domains, and it is localised in the nucleus and in the cytoplasm. ORF 3b is also predicted to contain DNA-binding and activator domains, and was found to localise in the mitochondrion. Besides that, in some of the non-infected and FIPV-infected cells nucleolar, perinuclear or nuclear membrane accumulation of the eGFP-tagged 3b was observed. The exact compartmental localisation of ORF 3c is yet to be determined. However, based on our co-localisation studies 3c does not seem to be localised in the ER-Golgi network, ERGIC or peroxisomes. The expression of 3c-eGFP is clearly cell type dependent, it is more stable in MARC 145 cells than in Fcwf-4 or CrFK cells, which might reflect in vivo stability differences of 3c in natural target cells (enterocytes vs. monocytes/macrophages).
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Affiliation(s)
- István Mészáros
- 1 Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungária krt. 21, H-1143 Budapest, Hungary
| | - Ferenc Olasz
- 1 Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungária krt. 21, H-1143 Budapest, Hungary
| | - Enikő Kádár-Hürkecz
- 1 Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungária krt. 21, H-1143 Budapest, Hungary
- 2 National Institute of Environmental Health, Budapest, Hungary
| | - Ádám Bálint
- 3 National Food Chain Safety Office Veterinary Diagnostic Directorate, Budapest, Hungary
| | - Ákos Hornyák
- 3 National Food Chain Safety Office Veterinary Diagnostic Directorate, Budapest, Hungary
| | - Sándor Belák
- 4 Department of Biomedical Sciences and Veterinary Public Health (BVF), Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - Zoltán Zádori
- 1 Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungária krt. 21, H-1143 Budapest, Hungary
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14
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Oguma K, Ohno M, Yoshida M, Sentsui H. Mutation of the S and 3c genes in genomes of feline coronaviruses. J Vet Med Sci 2018; 80:1094-1100. [PMID: 29769478 PMCID: PMC6068308 DOI: 10.1292/jvms.17-0704] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Feline coronavirus (FCoV) is classified into two biotypes based on its pathogenicity in cats: a feline enteric coronavirus of low pathogenicity and a highly virulent feline infectious
peritonitis virus. It has been suspected that FCoV alters its biotype via mutations in the viral genome. The S and 3c genes of FCoV have been considered the
candidates for viral pathogenicity conversion. In the present study, FCoVs were analyzed for the frequency and location of mutations in the S and 3c genes
from faecal samples of cats in an animal shelter and the faeces, effusions, and tissues of cats that were referred to veterinary hospitals. Our results indicated that approximately 95% FCoVs
in faeces did not carry mutations in the two genes. However, 80% FCoVs in effusion samples exhibited mutations in the S and 3c genes with remainder
displaying a mutation in the S or 3c gene. It was also suggested that mutational analysis of the 3c gene could be useful for studying the
horizontal transmission of FCoVs in multi-cat environments.
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Affiliation(s)
- Keisuke Oguma
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Megumi Ohno
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Mayuko Yoshida
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan.,Present address: Okinawa Zoo and Museum Foundation, 5-7-1 Goya, Okinawa-shi, Okinawa 904-0021, Japan
| | - Hiroshi Sentsui
- Laboratory of Veterinary Epizootiology, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
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15
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Barker EN, Stranieri A, Helps CR, Porter EL, Davidson AD, Day MJ, Knowles T, Kipar A, Tasker S. Limitations of using feline coronavirus spike protein gene mutations to diagnose feline infectious peritonitis. Vet Res 2017; 48:60. [PMID: 28982390 PMCID: PMC5629788 DOI: 10.1186/s13567-017-0467-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 09/15/2017] [Indexed: 12/23/2022] Open
Abstract
Feline infectious peritonitis (FIP) is a fatal disease of cats, and a sequela of systemic feline coronavirus (FCoV) infection. Mutations in the viral spike (S) gene have been associated with FCoVs found in tissues from cats with FIP, but not FCoVs found in faeces from healthy cats, and are implicated in monocyte/macrophage tropism and systemic spread. This study was designed to determine whether S gene mutation analysis can reliably diagnose FIP. Cats were categorised as with FIP (n = 57) or without FIP (n = 45) based on gross post-mortem and histopathological examination including immunohistochemistry for FCoV antigen. RNA was purified from available tissue, fluid and faeces. Reverse-transcriptase quantitative-PCR (RT-qPCR) was performed on all samples using FCoV-specific primers, followed by sequencing of a section of the S gene on RT-qPCR positive samples. Samples were available from a total of 102 cats. Tissue, fluid, and faecal samples from cats with FIP were more likely to be FCoV RT-qPCR-positive (90.4, 78.4 and 64.6% respectively) than those from cats without FIP (7.8, 2.1 and 20% respectively). Identification of S gene mutated FCoVs as an additional step to the detection of FCoV alone, only moderately increased specificity for tissue samples (from 92.6 to 94.6%) but specificity was unchanged for fluid samples (97.9%) for FIP diagnosis; however, sensitivity was markedly decreased for tissue (from 89.8 to 80.9%) and fluid samples (from 78.4 to 60%) for FIP diagnosis. These findings demonstrate that S gene mutation analysis in FCoVs does not substantially improve the ability to diagnose FIP as compared to detection of FCoV alone.
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Affiliation(s)
- Emily N Barker
- School of Veterinary Sciences, University of Bristol, Bristol, UK.
| | | | - Chris R Helps
- School of Veterinary Sciences, University of Bristol, Bristol, UK
| | - Emily L Porter
- School of Veterinary Sciences, University of Bristol, Bristol, UK
| | - Andrew D Davidson
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Michael J Day
- School of Veterinary Sciences, University of Bristol, Bristol, UK
| | - Toby Knowles
- School of Veterinary Sciences, University of Bristol, Bristol, UK
| | - Anja Kipar
- Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Institute of Global Health, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK
| | - Séverine Tasker
- School of Veterinary Sciences, University of Bristol, Bristol, UK
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16
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Lythgoe KA, Gardner A, Pybus OG, Grove J. Short-Sighted Virus Evolution and a Germline Hypothesis for Chronic Viral Infections. Trends Microbiol 2017; 25:336-348. [PMID: 28377208 PMCID: PMC5405858 DOI: 10.1016/j.tim.2017.03.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/03/2017] [Accepted: 03/03/2017] [Indexed: 12/24/2022]
Abstract
With extremely short generation times and high mutability, many viruses can rapidly evolve and adapt to changing environments. This ability is generally beneficial to viruses as it allows them to evade host immune responses, evolve new behaviours, and exploit ecological niches. However, natural selection typically generates adaptation in response to the immediate selection pressures that a virus experiences in its current host. Consequently, we argue that some viruses, particularly those characterised by long durations of infection and ongoing replication, may be susceptible to short-sighted evolution, whereby a virus' adaptation to its current host will be detrimental to its onward transmission within the host population. Here we outline the concept of short-sighted viral evolution and provide examples of how it may negatively impact viral transmission among hosts. We also propose that viruses that are vulnerable to short-sighted evolution may exhibit strategies that minimise its effects. We speculate on the various mechanisms by which this may be achieved, including viral life history strategies that result in low rates of within-host evolution, or the establishment of a 'germline' lineage of viruses that avoids short-sighted evolution. These concepts provide a new perspective on the way in which some viruses have been able to establish and maintain global pandemics.
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Affiliation(s)
| | - Andy Gardner
- School of Biology, University of St Andrews, St Andrews, KY16 9TH, UK
| | - Oliver G Pybus
- Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK
| | - Joe Grove
- Division of Infection and Immunity, Institute of Immunity and Transplantation, University College London, London, WC1E 6BT, UK
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17
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Felten S, Weider K, Doenges S, Gruendl S, Matiasek K, Hermanns W, Mueller E, Matiasek L, Fischer A, Weber K, Hirschberger J, Wess G, Hartmann K. Detection of feline coronavirus spike gene mutations as a tool to diagnose feline infectious peritonitis. J Feline Med Surg 2016; 19:321-335. [PMID: 26701958 DOI: 10.1177/1098612x15623824] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Objectives Feline infectious peritonitis (FIP) is an important cause of death in the cat population worldwide. The ante-mortem diagnosis of FIP in clinical cases is still challenging. In cats without effusion, a definitive diagnosis can only be achieved post mortem or with invasive methods. The aim of this study was to evaluate the use of a combined reverse transcriptase nested polymerase chain reaction (RT-nPCR) and sequencing approach in the diagnosis of FIP, detecting mutations at two different nucleotide positions within the spike (S) gene. Methods The study population consisted of 64 cats with confirmed FIP and 63 cats in which FIP was initially suspected due to similar clinical or laboratory signs, but that were definitively diagnosed with another disease. Serum/plasma and/or effusion samples of these cats were examined for feline coronavirus (FCoV) RNA by RT-nPCR and, if positive, PCR products were sequenced for nucleotide transitions within the S gene. Results Specificity of RT-nPCR was 100% in all materials (95% confidence interval [CI] in serum/plasma 83.9-100.0; 95% CI in effusion 93.0-100.0). The specificity of the sequencing step could not be determined as none of the cats of the control group tested positive for FCoV RNA. Sensitivity of the 'combined RT-nPCR and sequencing approach' was 6.5% (95% CI 0.8-21.4) in serum/plasma and 65.3% (95% CI 50.4-78.3) in effusion. Conclusions and relevance A positive result is highly indicative of the presence of FIP, but as none of the control cats tested positive by RT-nPCR, it was not possible to confirm that the FCoV mutant described can only be found in cats with FIP. Further studies are necessary to evaluate the usefulness of the sequencing step including FCoV-RNA-positive cats with and without FIP. A negative result cannot be used to exclude the disease, especially when only serum/plasma samples are available.
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Affiliation(s)
- Sandra Felten
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | | | - Stephanie Doenges
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Stefanie Gruendl
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Kaspar Matiasek
- 3 Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Walter Hermanns
- 3 Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | | | - Lara Matiasek
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Andrea Fischer
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Karin Weber
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Johannes Hirschberger
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Gerhard Wess
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Katrin Hartmann
- 1 Clinic of Small Animal Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
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18
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Feline Coronavirus 3c Protein: A Candidate for a Virulence Marker? BIOMED RESEARCH INTERNATIONAL 2016; 2016:8560691. [PMID: 27243037 PMCID: PMC4868892 DOI: 10.1155/2016/8560691] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/01/2016] [Accepted: 04/10/2016] [Indexed: 11/17/2022]
Abstract
Feline infectious peritonitis virus (FIPV) is highly virulent and responsible for the highly fatal disease feline infectious peritonitis (FIP), whereas feline enteric coronavirus (FECV) is widespread among the feline population and typically causes asymptomatic infections. Some candidates for genetic markers capable of differentiating these two pathotypes of a unique virus (feline coronavirus) have been proposed by several studies. In the present survey, in order to search for markers that can differentiate FECV and FIPV, several clones of the 3a–c, E, and M genes were sequenced from samples obtained from cats with or without FIP. All genes showed genetic diversity and suggested the presence of FCoV mutant spectrum capable of producing a virulent pathotype in an individual-specific way. In addition, all the feline coronavirus FIPV strains demonstrated a truncated 3c protein, and the 3c gene was the only observed pathotypic marker for FCoVs, showing that 3c gene is a candidate marker for the distinction between the two pathotypes when the mutant spectrum is taken into account.
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