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Balboni A, Facile V, Gallina L, Sabetti MC, Dondi F, Battilani M. Molecular Detection and Genetic Characterization of Feline Immunodeficiency Virus (FIV) in Seropositive Cats in Northern Italy. Pathogens 2024; 13:463. [PMID: 38921761 PMCID: PMC11206283 DOI: 10.3390/pathogens13060463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 06/27/2024] Open
Abstract
Feline immunodeficiency virus (FIV) is responsible for immunodeficiency syndrome in cats. Several viral subtypes have been identified, each with a variable geographical distribution. To date, the subtype B is known to be the genotype spread in Italy. In this study, the genetic diversity of FIV in northern Italy was assessed by detecting proviral DNA in the blood samples of 50 cats determined to be positive through an anti-FIV antibodies test. These cats were tested using six different PCR assays, and the identified viruses were sequenced and analyzed. Forty-eight cats were confirmed positive, and several FIV subtypes were characterized. As expected, the subtype B was the most commonly observed, and the subtype A was reported for the first time in Italy. Moreover, a new taxon possibly representing an additional FIV subtype was detected, and one virus belonging to subtype B potentially had a recombinant origin. The genetic variability between the FIV viruses that emerged in this study may lead to the potential diagnostic failure of single molecular tests. Therefore, a new diagnostic strategy, which adopts different molecular tests and sequencing, is recommended to monitor the evolution and spread of FIV.
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Affiliation(s)
- Andrea Balboni
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Ozzano Emilia, 40064 Bologna, Italy; (A.B.); (V.F.); (F.D.); (M.B.)
| | - Veronica Facile
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Ozzano Emilia, 40064 Bologna, Italy; (A.B.); (V.F.); (F.D.); (M.B.)
| | - Laura Gallina
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Ozzano Emilia, 40064 Bologna, Italy; (A.B.); (V.F.); (F.D.); (M.B.)
| | | | - Francesco Dondi
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Ozzano Emilia, 40064 Bologna, Italy; (A.B.); (V.F.); (F.D.); (M.B.)
| | - Mara Battilani
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Ozzano Emilia, 40064 Bologna, Italy; (A.B.); (V.F.); (F.D.); (M.B.)
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Clinicopathological and Epidemiological Findings in Pet Cats Naturally Infected with Feline Immunodeficiency Virus (FIV) in Australia. Viruses 2022; 14:v14102177. [PMID: 36298731 PMCID: PMC9608632 DOI: 10.3390/v14102177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 11/25/2022] Open
Abstract
Feline immunodeficiency virus (FIV) infection in experimentally infected domestic cats produces characteristic clinical manifestations including hematological changes, neurological disease, neoplasia (most notably lymphoma) and lymphopenia-mediated immunodeficiency predisposing cats to a range of secondary infections. Conflicting reports exist, however, with regard to disease associations and survival time in naturally FIV-infected cats. The purpose of this retrospective case−control study was to investigate the effect of natural FIV infection on hematological, blood biochemical and urinalysis parameters and survival time in three cohorts of pet cats in Australia. Cohorts 1 and 2 were recruited from a large veterinary hospital in Melbourne, Victoria (n = 525 and 282), while a third cohort consisted of cats recruited from around Australia as part of a FIV field vaccine efficacy trial (n = 425). FIV-infected cats in cohorts 1, 2 and 3 were found to have 15/37 (41%), 13/39 (33%) and 2/13 (15%) clinicopathological parameters significantly different to FIV-uninfected cats, respectively. Two changes in FIV-infected cats in cohort 1, hypochromia (low hemoglobin) and hyperglobulinemia, were outside the supplied reference intervals and should serve as diagnostic triggers for FIV testing. Kaplan−Meier survival analysis of cats in cohorts 1 and 2 combined did not find any difference between FIV-infected and FIV-uninfected cats, however a confounding factor was a large euthanasia rate within the first 12 months in both groups. Three significant (p < 0.05) spatial clusters of FIV infection were identified in Melbourne. A possible relationship between FIV infection status and socioeconomic disadvantage was discovered, based on three government indices of socioeconomic status (p < 0.001). Until longitudinal field studies are performed in Australia to further investigate the long-term effects of natural FIV infection, Australian veterinarians should consider FIV to be an important infection of pet cats, and recommend measures to prevent FIV infection.
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Westman ME, Coggins SJ, van Dorsselaer M, Norris JM, Squires RA, Thompson M, Malik R. Feline immunodeficiency virus (FIV) infection in domestic pet cats in Australia and New Zealand: Guidelines for diagnosis, prevention and management. Aust Vet J 2022; 100:345-359. [PMID: 35578381 PMCID: PMC9546031 DOI: 10.1111/avj.13166] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/13/2022] [Accepted: 04/16/2022] [Indexed: 01/25/2023]
Abstract
Despite the passage of over 30 years since its discovery, the importance of feline immunodeficiency virus (FIV) on the health and longevity of infected domestic cats is hotly debated amongst feline experts. Notwithstanding the absence of good quality information, Australian and New Zealand (NZ) veterinarians should aim to minimise the exposure of cats to FIV. The most reliable way to achieve this goal is to recommend that all pet cats are kept exclusively indoors, or with secure outdoor access (e.g., cat enclosures, secure gardens), with FIV testing of any in‐contact cats. All animal holding facilities should aim to individually house adult cats to limit the spread of FIV infection in groups of animals that are stressed and do not have established social hierarchies. Point‐of‐care (PoC) FIV antibody tests are available in Australia and NZ that can distinguish FIV‐infected and uninfected FIV‐vaccinated cats (Witness™ and Anigen Rapid™). Although testing of whole blood, serum or plasma remains the gold standard for FIV diagnosis, PoC testing using saliva may offer a welfare‐friendly alternative in the future. PCR testing to detect FIV infection is not recommended as a screening procedure since a negative PCR result does not rule out FIV infection and is only recommended in specific scenarios. Australia and NZ are two of three countries where a dual subtype FIV vaccine (Fel‐O‐Vax® FIV) is available and offers a further avenue for disease prevention. Since FIV vaccination only has a reported field effectiveness of 56% in Australia, and possibly lower in NZ, FIV‐vaccinated cats should undergo annual FIV testing prior to annual FIV re‐vaccination using a suitable PoC kit to check infection has not occurred in the preceding year. With FIV‐infected cats, clinicians should strive to be even more thorough than usual at detecting early signs of disease. The most effective way to enhance the quality of life and life expectancy of FIV‐infected cats is to optimise basic husbandry and to treat any concurrent conditions early in the disease course. Currently, no available drugs are registered for the treatment of FIV infection. Critically, the euthanasia of healthy FIV‐infected cats, and sick FIV‐infected cats without appropriate clinical investigations, should not occur.
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Affiliation(s)
- M E Westman
- Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
| | - S J Coggins
- Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
| | | | - J M Norris
- Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia.,The Sydney Institute for Infectious Diseases, The University of Sydney, Sydney, New South Wales, Australia
| | - R A Squires
- College of Public Health, Medical & Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
| | - M Thompson
- Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
| | - R Malik
- Centre for Veterinary Education, The University of Sydney, Sydney, New South Wales, Australia.,School of Veterinary and Animal Science, Charles Sturt University, Wagga Wagga, New South Wales, Australia
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Muz D, Can H, Karakavuk M, Döşkaya M, Özdemir HG, Değirmenci Döşkaya A, Atalay Şahar E, Pektaş B, Karakuş M, Töz S, Özbel Y, Gürüz AY, Muz MN. The molecular and serological investigation of Feline immunodeficiency virus and Feline leukemia virus in stray cats of Western Turkey. Comp Immunol Microbiol Infect Dis 2021; 78:101688. [PMID: 34229197 DOI: 10.1016/j.cimid.2021.101688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/11/2021] [Accepted: 06/27/2021] [Indexed: 11/18/2022]
Abstract
This study aimed to investigate the Feline immunodeficiency virus (FIV) / Feline leukemia virus (FeLV) infection prevalence among looking healthy stray cats in Western Turkey by serologic and molecular-based tests. A total of 1008 blood samples from the stray cats were used in this study. All samples were tested for FIV antibodies / proviral DNA and FeLV antibodies / antigens / proviral DNA. The genetic characterization and phylogenetic analysis of FeLV and FIV were carried out in this study. These cats also tested for Leishmaniasis and Toxoplasmosis previously. FIV Ab and proviral DNA detected in 25.2 % and 25.5 % of samples, respectively. FeLV Ab, Ag, proviral DNA positivity was in 45.2 %, in 3.3 %, in 69.7 %, respectively. The molecular detection and phylogenetic analysis of the current FeLV pol gene and FIV gag gene performed. The molecular characterization for the pol gene of FeLV (enFeLV and exFeLV) among Turkey's cat population was reported for the first time. The exFeLV pol sequences closer to the FeLV-A genotype, and the enFeLV pol sequences overlapped with other enFeLV. The current FIV gag sequences were clustered within the subtypes A, B, and C. The findings revealed FeLV subtype A and FIV subtype-A, subtype-B, subtype-C circulate among Turkish stray cats. Single and multiple co-infection positivity was found higher compared to previous reports.
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Affiliation(s)
- Dilek Muz
- Department of Virology, Tekirdag Namik Kemal University, Faculty of Veterinary Medicine, Tekirdag 59030, Turkey.
| | - Hüseyin Can
- Department of Molecular Biology, Ege University Faculty of Sciences, Bornova, Izmir, 35100, Turkey
| | - Muhammet Karakavuk
- Department of Parasitology, Ege University Medical School, Bornova, Izmir, 35100, Turkey; Odemiş Training Collage, Ege University, Odemiş, İzmir, 35400, Turkey
| | - Mert Döşkaya
- Department of Parasitology, Ege University Medical School, Bornova, Izmir, 35100, Turkey
| | | | | | - Esra Atalay Şahar
- Department of Molecular Biology, Ege University Faculty of Sciences, Bornova, Izmir, 35100, Turkey
| | - Bayram Pektaş
- Izmir Atatürk Training and Research Hospital, Department of Microbiology, Yeşilyurt, Izmir, Turkey
| | - Mehmet Karakuş
- Department of Medical Microbiology, Hamidiye Faculty of Medicine, University of Health Sciences, İstanbul, Turkey
| | - Seray Töz
- Department of Parasitology, Ege University Medical School, Bornova, Izmir, 35100, Turkey
| | - Yusuf Özbel
- Department of Parasitology, Ege University Medical School, Bornova, Izmir, 35100, Turkey
| | - Adnan Yüksel Gürüz
- Department of Parasitology, Ege University Medical School, Bornova, Izmir, 35100, Turkey
| | - Mustafa Necati Muz
- Department of Parasitology, Tekirdag Namik Kemal University, Faculty of Veterinary Medicine, Tekirdag 59030, Turkey
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Szilasi A, Dénes L, Krikó E, Murray C, Mándoki M, Balka G. Prevalence of feline leukaemia virus and feline immunodeficiency virus in domestic cats in Ireland. Acta Vet Hung 2021; 68:413-420. [PMID: 33459612 DOI: 10.1556/004.2020.00056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/19/2020] [Indexed: 12/15/2022]
Abstract
Feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) are retroviruses affecting felid species worldwide. A study was performed over a period of 5 months in Ireland with the aim to get an updated and more realistic prevalence of these retroviruses. A total of 183 EDTA-anticoagulated whole-blood samples were collected from cats distributed between 10 clinics. The samples were tested using both point-of-care enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). Basic clinical data and vaccination history were also recorded for the sampled cats. The results of ELISA tests showed a prevalence of 10.4 and 3.3% for FIV and FeLV, respectively, and an apparent prevalence of 9.3% for FIV and 11.6% for FeLV with PCR. Phylogenetic analysis of the partial polymerase (pol) gene sequences obtained from 8 FIV-positive strains showed that all but one of the Irish strains belonged to FIV subtype A, and one to subtype B. The overall mean genetic similarity between the analysed strains was 91.15%.
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Affiliation(s)
- Anna Szilasi
- 1Department of Pathology, University of Veterinary Medicine, István u. 2, H-1078 Budapest, Hungary
| | - Lilla Dénes
- 1Department of Pathology, University of Veterinary Medicine, István u. 2, H-1078 Budapest, Hungary
| | - Eszter Krikó
- 2Centre for Bioinformatics, University of Veterinary Medicine, Budapest, Hungary
| | - Caoimhe Murray
- 3Suirside Veterinary Clinic, Townparks, Carrick-On-Suir, Co. Tipperary, Ireland
| | - Míra Mándoki
- 1Department of Pathology, University of Veterinary Medicine, István u. 2, H-1078 Budapest, Hungary
| | - Gyula Balka
- 1Department of Pathology, University of Veterinary Medicine, István u. 2, H-1078 Budapest, Hungary
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Lack of protection against feline immunodeficiency virus infection among domestic cats in New Zealand vaccinated with the Fel-O-Vax® FIV vaccine. Vet Microbiol 2020; 250:108865. [PMID: 33045631 DOI: 10.1016/j.vetmic.2020.108865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/17/2020] [Indexed: 11/20/2022]
Abstract
Infections with feline immunodeficiency virus (FIV) are common in New Zealand, although the impact of those infections on the health status of the cats remains unclear. Although many cats are vaccinated yearly with a commercial FIV vaccine containing FIV subtypes A and D, the effectiveness of this vaccine in protection against infection with field FIVs is unclear, as a high proportion of New Zealand viruses belong to subtype C. The objective of the study was to compare the frequency of FIV infection among adult FIV-vaccinated and FIV-unvaccinated domestic cats with access to outdoors. Buccal swabs were collected by the participating veterinarians and tested for the presence of FIV provirus by quantitative PCR. Overall, 26/185 (14.0 %) samples were positive for FIV, including 7/82 (8.5 %) samples from FIV-unvaccinated and 19/103 (18.4 %) from FIV-vaccinated cats. There was no protective effect of vaccination on FIV infection among sampled cats (p = 0.05). Partial sequences of the FIV envelope gene from five New Zealand viruses were analysed by the maximum likelihood method. All clustered with other New Zealand FIV sequences from subtypes A (n = 2), C (n = 2) or putative recombinant viruses (n = 1). While the FIV vaccination did not prevent FIV infection among sampled cats, it may have had an impact on transmissibility of the virus or on disease progression. As neither was addressed in the current study, further research is needed to fully assess the potential benefits of FIV vaccination. Considering the frequency of FIV infection in FIV-vaccinated cats, FIV infection status should be monitored not only before the first vaccination, but before each yearly booster.
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Decreased Sensitivity of the Serological Detection of Feline Immunodeficiency Virus Infection Potentially Due to Imported Genetic Variants. Viruses 2019; 11:v11080697. [PMID: 31370217 PMCID: PMC6722909 DOI: 10.3390/v11080697] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 01/02/2023] Open
Abstract
Feline immunodeficiency virus (FIV) is a lentivirus of domestic cats worldwide. Diagnosis usually relies on antibody screening by point-of-care tests (POCT), e.g., by enzyme-linked immunosorbent assays (ELISA), and confirmation using Western blot (WB). We increasingly observed ELISA-negative, WB-positive samples and aimed to substantiate these observations using 1194 serum/plasma samples collected from 1998 to 2019 primarily from FIV-suspect cats. While 441 samples tested positive and 375 tested negative by ELISA and WB, 81 samples had discordant results: 70 were false ELISA-negative (WB-positive) and 11 were false ELISA-positive (WB-negative); 297 ambiguous results were not analyzed further. The diagnostic sensitivity and specificity of the ELISA (82% and 91%, respectively) were lower than those reported in 1995 (98% and 97%, respectively). The diagnostic efficiency was reduced from 97% to 86%. False ELISA-negative samples originated mainly (54%) from Switzerland (1995: 0%). Sixty-four false ELISA-negative samples were available for POCT (SNAPTM/WITNESSR): five were POCT-positive. FIV RT-PCR was positive for two of these samples and was weakly positive for two ELISA- and POCT-negative samples. Low viral loads prohibited sequencing. Our results suggest that FIV diagnosis has become more challenging, probably due to increasing travel by cats and the introduction of new FIV isolates not recognized by screening assays.
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Szilasi A, Dénes L, Krikó E, Heenemann K, Ertl R, Mándoki M, Vahlenkamp TW, Balka G. Prevalence of feline immunodeficiency virus and feline leukaemia virus in domestic cats in Hungary. JFMS Open Rep 2019; 5:2055116919892094. [PMID: 31839979 PMCID: PMC6904780 DOI: 10.1177/2055116919892094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
OBJECTIVES Feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) are retroviruses affecting cats worldwide. The objectives of the study were to estimate the prevalence of these retroviruses in domestic cats in Hungary and to characterise the phylogenetic relationships of FIV strains. METHODS A total of 335 anticoagulated whole-blood samples obtained from both a healthy and ill cat population were examined for the presence of FIV and FeLV with two methods: ELISA and PCR. Statistical analysis was carried out to analyse the data obtained. Sequencing and phylogenetic analysis of partial polymerase (pol) gene sequences was performed to describe circulating FIV subtypes. RESULTS Statistical analysis showed 11.8% and 9.9% true prevalence of FeLV and FIV, respectively, with ELISA. The apparent prevalence calculated from the PCR results were 17.3% for FeLV and 13.1% for FIV. Phylogenetic analysis of partial pol gene sequences obtained from 22 FIV strains showed that all observed Hungarian strains belonged to FIV subtype B. The strains were grouped into several monophyletic subgroups reflecting the geographic locations of the origin of the samples. The overall mean genetic similarity between the analysed strains was 98.2%. CONCLUSIONS AND RELEVANCE We report the first thorough overview of the prevalence of FeLV and FIV in Hungary, which is relatively high, and give insight into the genetic diversity of Hungarian strains of FIV.
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Affiliation(s)
- Anna Szilasi
- Department of Pathology, University of
Veterinary Medicine, Budapest, Pest, Hungary
| | - Lilla Dénes
- Department of Pathology, University of
Veterinary Medicine, Budapest, Pest, Hungary
| | - Eszter Krikó
- Centre for Bioinformatics, University of
Veterinary Medicine, Budapest, Pest, Hungary
| | - Kristin Heenemann
- Institute of Virology, Faculty of
Veterinary Medicine, Leipzig University, Leipzig, Sachsen, Germany
| | - Reinhard Ertl
- VetCore Facility for Research,
University of Veterinary Medicine, Vienna, Austria
| | - Míra Mándoki
- Department of Pathology, University of
Veterinary Medicine, Budapest, Pest, Hungary
| | - Thomas W Vahlenkamp
- Institute of Virology, Faculty of
Veterinary Medicine, Leipzig University, Leipzig, Sachsen, Germany
| | - Gyula Balka
- Department of Pathology, University of
Veterinary Medicine, Budapest, Pest, Hungary
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Westman ME, Malik R, Norris JM. Diagnosing feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) infection: an update for clinicians. Aust Vet J 2019; 97:47-55. [DOI: 10.1111/avj.12781] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 10/20/2018] [Accepted: 10/23/2018] [Indexed: 11/29/2022]
Affiliation(s)
- ME Westman
- Sydney School of Veterinary Science; The University of Sydney; NSW Australia
| | - R Malik
- Centre for Veterinary Education; The University of Sydney; NSW Australia
| | - JM Norris
- Sydney School of Veterinary Science; The University of Sydney; NSW Australia
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10
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Westman M, Malik R, Hall E, Harris M, Norris J. The protective rate of the feline immunodeficiency virus vaccine: An Australian field study. Vaccine 2016; 34:4752-4758. [DOI: 10.1016/j.vaccine.2016.06.060] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/15/2016] [Accepted: 06/18/2016] [Indexed: 10/21/2022]
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Phylogenetic characterisation of feline immunodeficiency virus in naturally infected cats in Croatia indicates additional heterogeneity of subtype B in Europe. Arch Virol 2016; 161:2567-73. [PMID: 27318929 DOI: 10.1007/s00705-016-2928-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 06/08/2016] [Indexed: 10/21/2022]
Abstract
This study was performed on 29 domestic cats with a variety of clinical signs, possibly related to FIV infection. Blood samples were tested by a rapid immunochromatographic (ICA) procedure for detection of FIV antibodies. Subsequently, polymerase chain reaction (PCR) was performed to amplify a portion of the proviral gag gene. All 11 positive PCR products were sequenced and compared with previously reported FIV sequences. Croatian proviral isolates that could be amplified were clustered within subtype B, and additional heterogeneity was confirmed by the formation of three separate clusters. Phylogenetic analysis of circulating strains in Croatia and in southeast Europe is necessary to improve diagnostic methods and selection of the appropriate vaccinal strains.
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Westman ME, Malik R, Hall E, Sheehy PA, Norris JM. Determining the feline immunodeficiency virus (FIV) status of FIV-vaccinated cats using point-of-care antibody kits. Comp Immunol Microbiol Infect Dis 2015; 42:43-52. [PMID: 26459979 DOI: 10.1016/j.cimid.2015.07.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 07/28/2015] [Accepted: 07/29/2015] [Indexed: 11/18/2022]
Abstract
This study challenges the commonly held view that the feline immunodeficiency virus (FIV) infection status of FIV-vaccinated cats cannot be determined using point-of-care antibody test kits due to indistinguishable antibody production in FIV-vaccinated and naturally FIV-infected cats. The performance of three commercially available point-of-care antibody test kits was compared in a mixed population of FIV-vaccinated (n=119) and FIV-unvaccinated (n=239) cats in Australia. FIV infection status was assigned by considering the results of all antibody kits in concert with results from a commercially available PCR assay (FIV RealPCR™). Two lateral flow immunochromatography test kits (Witness FeLV/FIV; Anigen Rapid FIV/FeLV) had excellent overall sensitivity (100%; 100%) and specificity (98%; 100%) and could discern the true FIV infection status of cats, irrespective of FIV vaccination history. The lateral flow ELISA test kit (SNAP FIV/FeLV Combo) could not determine if antibodies detected were due to previous FIV vaccination, natural FIV infection, or both. The sensitivity and specificity of FIV RealPCR™ for detection of viral and proviral nucleic acid was 92% and 99%, respectively. These results will potentially change the way veterinary practitioners screen for FIV in jurisdictions where FIV vaccination is practiced, especially in shelter scenarios where the feasibility of mass screening is impacted by the cost of testing.
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Affiliation(s)
- Mark E Westman
- Faculty of Veterinary Science, The University of Sydney, NSW 2006, Australia.
| | - Richard Malik
- Centre for Veterinary Education, The University of Sydney, NSW 2006, Australia
| | - Evelyn Hall
- Faculty of Veterinary Science, The University of Sydney, NSW 2006, Australia
| | - Paul A Sheehy
- Faculty of Veterinary Science, The University of Sydney, NSW 2006, Australia
| | - Jacqueline M Norris
- Faculty of Veterinary Science, The University of Sydney, NSW 2006, Australia.
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Wilkes RP, Kania SA, Tsai YL, Lee PYA, Chang HH, Ma LJ, Chang HFG, Wang HTT. Rapid and sensitive detection of Feline immunodeficiency virus using an insulated isothermal PCR-based assay with a point-of-need PCR detection platform. J Vet Diagn Invest 2015; 27:510-5. [PMID: 26185125 DOI: 10.1177/1040638715593597] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Feline immunodeficiency virus (FIV) is an important infectious agent of cats. Clinical syndromes resulting from FIV infection include immunodeficiency, opportunistic infections, and neoplasia. In our study, a 5' long terminal repeat/gag region-based reverse transcription insulated isothermal polymerase chain reaction (RT-iiPCR) was developed to amplify all known FIV strains to facilitate point-of-need FIV diagnosis. The RT-iiPCR method was applied in a point-of-need PCR detection platform--a field-deployable device capable of generating automatically interpreted RT-iiPCR results from nucleic acids within 1 hr. Limit of detection 95% of FIV RT-iiPCR was calculated to be 95 copies standard in vitro transcription RNA per reaction. Endpoint dilution studies with serial dilutions of an ATCC FIV type strain showed that the sensitivity of lyophilized FIV RT-iiPCR reagent was comparable to that of a reference nested PCR. The established reaction did not amplify any nontargeted feline pathogens, including Felid herpesvirus 1, feline coronavirus, Feline calicivirus, Feline leukemia virus, Mycoplasma haemofelis, and Chlamydophila felis. Based on analysis of 76 clinical samples (including blood and bone marrow) with the FIV RT-iiPCR, test sensitivity was 97.78% (44/45), specificity was 100.00% (31/31), and agreement was 98.65% (75/76), determined against a reference nested-PCR assay. A kappa value of 0.97 indicated excellent correlation between these 2 methods. The lyophilized FIV RT-iiPCR reagent, deployed on a user-friendly portable device, has potential utility for rapid and easy point-of-need detection of FIV in cats.
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Affiliation(s)
- Rebecca Penrose Wilkes
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, TN (Wilkes, Kania)GeneReach USA, Lexington, MA (Tsai, Lee, Chang, Ma, Chang, Wang)
| | - Stephen A Kania
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, TN (Wilkes, Kania)GeneReach USA, Lexington, MA (Tsai, Lee, Chang, Ma, Chang, Wang)
| | - Yun-Long Tsai
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, TN (Wilkes, Kania)GeneReach USA, Lexington, MA (Tsai, Lee, Chang, Ma, Chang, Wang)
| | - Pei-Yu Alison Lee
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, TN (Wilkes, Kania)GeneReach USA, Lexington, MA (Tsai, Lee, Chang, Ma, Chang, Wang)
| | - Hsiu-Hui Chang
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, TN (Wilkes, Kania)GeneReach USA, Lexington, MA (Tsai, Lee, Chang, Ma, Chang, Wang)
| | - Li-Juan Ma
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, TN (Wilkes, Kania)GeneReach USA, Lexington, MA (Tsai, Lee, Chang, Ma, Chang, Wang)
| | - Hsiao-Fen Grace Chang
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, TN (Wilkes, Kania)GeneReach USA, Lexington, MA (Tsai, Lee, Chang, Ma, Chang, Wang)
| | - Hwa-Tang Thomas Wang
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, TN (Wilkes, Kania)GeneReach USA, Lexington, MA (Tsai, Lee, Chang, Ma, Chang, Wang)
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Bęczkowski PM, Hughes J, Biek R, Litster A, Willett BJ, Hosie MJ. Feline immunodeficiency virus (FIV) env recombinants are common in natural infections. Retrovirology 2014; 11:80. [PMID: 25699660 PMCID: PMC4180853 DOI: 10.1186/s12977-014-0080-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 09/01/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recombination is a common feature of retroviral biology and one of the most important factors responsible for generating viral diversity at both the intra-host and the population levels. However, relatively little is known about rates and molecular processes of recombination for retroviruses other than HIV, including important model viruses such as feline immunodeficiency virus (FIV). RESULTS We investigated recombination in complete FIV env gene sequences (n = 355) isolated from 43 naturally infected cats. We demonstrated that recombination is abundant in natural FIV infection, with over 41% of the cats being infected with viruses containing recombinant env genes. In addition, we identified shared recombination breakpoints; the most significant hotspot occurred between the leader/signal fragment and the remainder of env. CONCLUSIONS Our results have identified the leader/signal fragment of env as an important site for recombination and highlight potential limitations of the current phylogenetic classification of FIV based on partial env sequences. Furthermore, the presence of abundant recombinant FIV in the USA poses a significant challenge for commercial diagnostic tests and should inform the development of the next generation of FIV vaccines.
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15
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Sykes JE. Feline Immunodeficiency Virus Infection. CANINE AND FELINE INFECTIOUS DISEASES 2014. [PMCID: PMC7152317 DOI: 10.1016/b978-1-4377-0795-3.00021-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Chang-Fung-Martel J, Gummow B, Burgess G, Fenton E, Squires R. A door-to-door prevalence study of feline immunodeficiency virus in an Australian suburb. J Feline Med Surg 2013; 15:1070-8. [PMID: 23739036 PMCID: PMC10816465 DOI: 10.1177/1098612x13491959] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
A door-to-door survey was conducted within the limits of the suburb of Douglas in northern Queensland, Australia, to determine the prevalence of feline immunodeficiency virus (FIV) infection in the overall population of domestic cats. Previous FIV prevalence studies have relied on convenience sampling strategies, leaving out an important group of pet cats that do not receive regular veterinary attention. Saliva was selected for testing because collection was non-invasive and was likely to achieve a high rate of participation. Ninety-six cats were surveyed and tested for salivary antibodies against FIV and with real-time polymerase chain reaction (PCR). PCR was considered to be the gold standard and a cat was considered to be FIV-positive if sequencing results on a PCR product of appropriate size matched previously published FIV genome sequences available in GenBank. Results showed 10/96 cats to be infected with FIV subtype A, indicating a prevalence of 10.4% (95% confidence interval: 4.4-16.4) in the area studied. High risk associations were established with the roaming lifestyle of the cat (P <0.002), presence of abscesses (P <0.03) and occurrence of bite wounds (P <0.10). This is the first known cross-sectional study of a population of urban northern Australian cats living in an affluent suburb and presenting saliva as a potential non-invasive sample for large-scale epidemiological surveys on FIV.
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Affiliation(s)
- Janine Chang-Fung-Martel
- School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland, Australia
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17
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Stickney AL, Dunowska M, Cave NJ. Sequence variation of the feline immunodeficiency virus genome and its clinical relevance. Vet Rec 2013; 172:607-14. [PMID: 23749359 DOI: 10.1136/vr.f101460] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The ongoing evolution of feline immunodeficiency virus (FIV) has resulted in the existence of a diverse continuum of viruses. FIV isolates differ with regards to their mutation and replication rates, plasma viral loads, cell tropism and the ability to induce apoptosis. Clinical disease in FIV-infected cats is also inconsistent. Genomic sequence variation of FIV is likely to be responsible for some of the variation in viral behaviour. The specific genetic sequences that influence these key viral properties remain to be determined. With knowledge of the specific key determinants of pathogenicity, there is the potential for veterinarians in the future to apply this information for prognostic purposes. Genomic sequence variation of FIV also presents an obstacle to effective vaccine development. Most challenge studies demonstrate acceptable efficacy of a dual-subtype FIV vaccine (Fel-O-Vax FIV) against FIV infection under experimental settings; however, vaccine efficacy in the field still remains to be proven. It is important that we discover the key determinants of immunity induced by this vaccine; such data would compliment vaccine field efficacy studies and provide the basis to make informed recommendations on its use.
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Affiliation(s)
- A L Stickney
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
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18
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Pathogenicity and rapid growth kinetics of feline immunodeficiency virus are linked to 3' elements. PLoS One 2011; 6:e24020. [PMID: 21887365 PMCID: PMC3162592 DOI: 10.1371/journal.pone.0024020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 07/28/2011] [Indexed: 11/19/2022] Open
Abstract
Chimeric viruses constructed between a highly pathogenic Feline Immunodeficiency Virus isolate (FIV-C36) and a less pathogenic but neurotropic strain (FIV-PPR) have been used to map viral genetic determinants of in vivo pathogenicity. Chimeric virus FIV-PCenv, which contains FIV-C36 genome from the 3′ region of pol to upstream of the 3′LTR on an FIV-PPR backbone, was previously shown to be replication-competent in vivo, inducing altered CD4+ T-cell and neutrophil profiles intermediate between parental strains following a delay in viral replication during initial infection. Examination of FIV-PCenv proviral sequences recovered at week 11 post-infection revealed two changes compared to initial viral inoculum; the most significant being arginine to histidine in the integrase region of Pol at residue 813 (R813H). Pooled plasma from the initial in vivo study was used to inoculate a second cohort of cats to determine whether similar virulence and kinetics could be established following primary infection. Viral replication kinetics and immunocyte profiles were monitored in blood, bone marrow, and saliva over a one-year period. Passaged FIV-PCenv again displayed intermediate phenotype between parental strains, but unlike primary experiments, the onset of acute viremia was not delayed. CD4/8 alterations were noted in all groups of animals, though significant changes from controls were delayed in FIV-PPR infected animals compared to FIV-C36 and FIV-PCenv. In vivo passage of FIV-PCenv increased replication-competence relative to the initial molecularly-cloned chimera in association with one adaptive nucleotide change in the 5′ end of the genome relative to primary tissue culture inoculum, while mutations in the 3′ end of the genome were not detected. The results are consistent with the interpretation that 3′ elements contribute to heightened virulence of FIV-C36, and that integrase residue 813 plays an important role in facilitating successful in vivo replication.
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19
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Phylogenetic characterisation of naturally occurring feline immunodeficiency virus in the United Kingdom. Vet Microbiol 2011; 150:239-47. [PMID: 21349661 PMCID: PMC3103826 DOI: 10.1016/j.vetmic.2011.01.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/20/2011] [Accepted: 01/24/2011] [Indexed: 11/23/2022]
Abstract
Feline immunodeficiency virus (FIV) is a significant pathogen of domestic and non-domestic felids worldwide. In domestic cats, FIV is classified into five distinct subtypes (A–E) with subtypes A and B distributed most widely. However, little is known about the degree of intrasubtype viral diversity and this may prove critical in determining whether monovalent vaccines are likely to protect against FIV strains within a single subtype. Here, we characterise novel env sequences from 47 FIV strains recovered from infected cats in the United Kingdom and its environs. Phylogenetic analyses revealed that all bar one sequence belonged to subtype A, the predominant subtype in Western Europe. A single sequence was identified as a likely subtype A/C recombinant, intriguing given that subtype C does not appear to exist in either the UK or North Western Europe and suggestive of a recombination event predating its introduction into the UK. Subtype A strains from the UK were not significantly differentiated from representative subtype A isolates found elsewhere suggesting multiple introductions of FIV into the country. Divergence among isolates was comparable to that observed for subtype A isolates worldwide, indicating that FIV in the UK covers the full spectrum of subtype A diversity seen globally. This study demonstrates that while subtype A is predominant in the UK, novel introductions may result in the emergence of novel subtypes or intersubtype recombinants, potentially circumventing vaccine strategies. However, the dominance of subtype A suggests that the development of a regional or subtype-specific protective vaccine for the UK could be achievable.
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20
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Hosie MJ, Addie D, Belák S, Boucraut-Baralon C, Egberink H, Frymus T, Gruffydd-Jones T, Hartmann K, Lloret A, Lutz H, Marsilio F, Pennisi MG, Radford AD, Thiry E, Truyen U, Horzinek MC. Feline immunodeficiency. ABCD guidelines on prevention and management. J Feline Med Surg 2009; 11:575-84. [PMID: 19481037 PMCID: PMC7129779 DOI: 10.1016/j.jfms.2009.05.006] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Overview Feline immunodeficiency virus (FIV) is a retrovirus closely related to human immunodeficiency virus. Most felids are susceptible to FIV, but humans are not. Feline immunodeficiency virus is endemic in domestic cat populations worldwide. The virus loses infectivity quickly outside the host and is susceptible to all disinfectants. Infection Feline immunodeficiency virus is transmitted via bites. The risk of transmission is low in households with socially well-adapted cats. Transmission from mother to kittens may occur, especially if the queen is undergoing an acute infection. Cats with FIV are persistently infected in spite of their ability to mount antibody and cell-mediated immune responses. Disease signs Infected cats generally remain free of clinical signs for several years, and some cats never develop disease, depending on the infecting isolate. Most clinical signs are the consequence of immunodeficiency and secondary infection. Typical manifestations are chronic gingivostomatitis, chronic rhinitis, lymphadenopathy, weight loss and immune-mediated glomerulonephritis. Diagnosis Positive in-practice ELISA results obtained in a low-prevalence or low-risk population should always be confirmed by a laboratory. Western blot is the ‘gold standard’ laboratory test for FIV serology. PCR-based assays vary in performance. Disease management Cats should never be euthanased solely on the basis of an FIV-positive test result. Cats infected with FIV may live as long as uninfected cats, with appropriate management. Asymptomatic FIV-infected cats should be neutered to avoid fighting and virus transmission. Infected cats should receive regular veterinary health checks. They can be housed in the same ward as other patients, but should be kept in individual cages. Vaccination recommendations At present, there is no FIV vaccine commercially available in Europe. Potential benefits and risks of vaccinating FIV-infected cats should be assessed on an individual cat basis. Needles and surgical instruments used on FIV-positive cats may transmit the virus to other cats, so strict hygiene is essential.
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21
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Iwata D, Holloway SA. Molecular subtyping of feline immunodeficiency virus from cats in Melbourne. Aust Vet J 2008; 86:385-9. [PMID: 18826508 DOI: 10.1111/j.1751-0813.2008.00336.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To determine the subtypes of feline immunodeficiency virus (FIV) present in the domestic cat population in Melbourne. METHODS Blood samples were collected from 42 cats that had serum antibodies against FIV. DNA was extracted and subjected to polymerase chain reaction (PCR) to amplify variable regions of the envelope (env) and group specific antigen (gag) genes of FIV. PCR products were directly sequenced or sequenced after cloning when direct sequencing yielded ambiguous results. Phylogenetic analysis was performed and comparisons made with representative sequences of different subtypes. RESULTS The variable region of the env gene was successfully amplified by PCR from 41 of the 42 cats. All 41 were found to cluster with subtype A env sequences. The variable region of the gag gene was successfully amplified by PCR from all 42 cats. Forty-one were found to cluster with subtype A gag genes and one was found to cluster with subtype B sequences, suggesting that it may be derived from a recombinant env A/gag B virus. CONCLUSIONS Subtype A is the predominant FIV type in Melbourne, although a subtype A/B recombinant was identified in the population of FIV positive cats. These results of env gene analysis were similar to those in a previous Australian study, suggesting that subtype A predominates in Australia. The results of the gag gene analysis show the importance of analysing multiple areas of the FIV genome when assigning FIV subtypes. Comparison with other major urban centres may provide useful information about the phylogenic diversity of FIV in Australia.
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Affiliation(s)
- D Iwata
- The University of Melbourne Veterinary Clinic and Hospital, Werribee, Vic, Australia
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22
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Kann RKC, Seddon JM, Meers J, Zwijnenberg RJG. Feline immunodeficiency virus subtypes in domestic cats in New Zealand. N Z Vet J 2007; 55:358-60. [DOI: 10.1080/00480169.2007.36795] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
Since feline immunodeficiency virus (FIV) was first isolated, international research efforts have been directed towards developing a protective vaccine, not least because it may provide a model for a candidate human immunodeficiency virus (HIV) vaccine. This article reviews the challenges facing vaccine development, the current state of knowledge and future prospects for FIV vaccination.
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Affiliation(s)
- M J Hosie
- Retrovirus Research Laboratory, Institute for Comparative Medicine, Faculty of Veterinary Medicine, The University of Glasgow
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Kann R, Seddon J, Kyaw-Tanner M, Meers J. Co-infection with different subtypes of feline immunodeficiency virus can complicate subtype assignment by phylogenetic analysis. Arch Virol 2007; 152:1187-93. [PMID: 17516035 DOI: 10.1007/s00705-007-0940-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Accepted: 01/08/2007] [Indexed: 10/23/2022]
Abstract
Phylogenetic analyses of the V3-V5 region of the env gene are used to determine Feline immunodeficiency virus (FIV) subtypes but can be complicated by co-infection with different subtypes or the presence of recombinant subtypes. FIV in blood samples from 30 domestic cats in New Zealand was subtyped by sequencing three overlapping fragments of the V3-V5 region of the env gene and 467 bp of the gag gene. Phylogenetic analyses revealed that the isolates clustered with subtype A and C viruses. Seven samples showed discrepancies in subtype assignment from analyses of their env gene sequences. Nucleotide differences of 19.6% and 20.9% in overlapping regions in two cats suggest co-infection with subtypes A and C.
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Affiliation(s)
- R Kann
- School of Veterinary Science, The University of Queensland, St. Lucia, Queensland, Australia
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25
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Hayward JJ, Taylor J, Rodrigo AG. Phylogenetic analysis of feline immunodeficiency virus in feral and companion domestic cats of New Zealand. J Virol 2006; 81:2999-3004. [PMID: 17192306 PMCID: PMC1866009 DOI: 10.1128/jvi.02090-06] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nested PCR was used to amplify envelope V3-V6 gene fragments of feline immunodeficiency virus (FIV) from New Zealand cats. Phylogenetic analyses established that subtypes A and C predominate among New Zealand cats, with clear evidence of intersubtype recombination. In addition, 17 sequences were identified that were distinct from all known FIV clades, and we tentatively suggest these belong to a novel subtype.
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Affiliation(s)
- Jessica J Hayward
- Bioinformatics Institute, Allan Wilson Centre for Molecular Ecology and Evolution, University of Auckland, Auckland Mail Centre, Auckland 1142, New Zealand
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