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He M, Feng S, Shi K, Shi Y, Long F, Yin Y, Li Z. One-step triplex TaqMan quantitative reverse transcription polymerase chain reaction for the detection of feline coronavirus, feline panleukopenia virus, and feline leukemia virus. Vet World 2024; 17:946-955. [PMID: 38911097 PMCID: PMC11188903 DOI: 10.14202/vetworld.2024.946-955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 04/10/2024] [Indexed: 06/25/2024] Open
Abstract
Background and Aim Feline coronavirus (FCoV), feline panleukopenia virus (FPV), and feline leukemia virus (FeLV) are prevalent throughout China and significantly threaten cat health. These viruses cause similar manifestations and pathological damage. Rapid and accurate diagnosis depends on detection in the laboratory. This study aimed to establish a reliable and rapid method for accurate detection of FCoV, FPV, and FeLV so that a definite diagnosis can be made and effective measures can be taken to prevent and control viral infection. Materials and Methods We designed three pairs of specific primers and probes for the detection of FCoV 5' untranslated region, FPV viral protein 2, and FeLV pol genes. Recombinant plasmid constructs were generated for use as standard plasmid constructs. Optimal reaction conditions, including primer and probe concentrations, reaction cycles, and annealing temperatures, were obtained on the basis of optimization tests. One-step triplex real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was successfully established to simultaneously detect FCoV, FPV, and FeLV. The specificity, sensitivity, and repeatability of the assay were analyzed, and its applicability was validated by testing 1175 clinical samples. Results One-step triplex RT-qPCR had a high degree of specificity only for the detection of FCoV, FPV, and FeLV; it had high sensitivity with limits of detection of 139.904, 143.099, and 152.079 copies/reaction for p-FCoV, p-FPV, and p-FeLV standard plasmid constructs, respectively, and it had reliable repeatability with 0.06%-0.87% intra-assay coefficients of variations. A total of 1175 clinical samples were examined for FCoV, FPV, and FeLV using triplex RT-qPCR, and the FCoV, FPV, and FeLV positivity rates were 18.47%, 19.91%, and 47.57%, respectively. The clinical sensitivity and specificity of one-step triplex RT-qPCR were 93.07% and 97.99%, respectively. Conclusion We developed a rapid and reliable one-step triplex RT-qPCR method for the detection of FCoV, FPV, and FeLV, which could be used as a diagnostic tool for clinical monitoring and diagnosis.
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Affiliation(s)
- Mengyi He
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Guangxi University, Nanning 530005, China
| | - Shuping Feng
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China
| | - Kaichuang Shi
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Guangxi University, Nanning 530005, China
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China
| | - Yandi Shi
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Guangxi University, Nanning 530005, China
| | - Feng Long
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China
| | - Yanwen Yin
- Guangxi Center for Animal Disease Control and Prevention, Nanning 530001, China
| | - Zongqiang Li
- Department of Basic Veterinary Medicine, College of Animal Science and Technology, Guangxi University, Nanning 530005, China
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Diesel LP, de Mello LS, de Oliveira Santana W, Ikuta N, Fonseca ASK, Kipper D, Redaelli R, Pereira VRZB, Streck AF, Lunge VR. Epidemiological Insights into Feline Leukemia Virus Infections in an Urban Cat ( Felis catus) Population from Brazil. Animals (Basel) 2024; 14:1051. [PMID: 38612290 PMCID: PMC11010845 DOI: 10.3390/ani14071051] [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: 02/18/2024] [Revised: 03/17/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Feline leukemia virus (FeLV) is a retrovirus distributed worldwide in domestic cats and with different outcomes (progressive, regressive, abortive, focal). The present study reports an epidemiological survey of FeLV frequency and the evaluation of some risk factors and the two main disease outcomes (progressive and regressive) in an urban cat population from Brazil. A total of 366 cats with sociodemographic information and p27 FeLV antigen test performed were included in the study. FeLV DNA (provirus) in the blood samples of all cats was detected via real-time polymerase chain reaction (qPCR). Plasma samples from 109 FeLV-positive and FeLV-negative cats were also submitted to reverse transcription (RT-qPCR) to determine the FeLV viral load. The results demonstrated that 112 (30.6%) cats were positive through the p27 antigen and/or qPCR. A risk factor analysis demonstrated that cats without vaccination against FeLV (OR 9.9, p < 0.001), clinically ill (OR 2.9, p < 0.001), with outdoors access (OR 2.7, p < 0.001), and exhibiting apathetic behavior (OR 3.1, p < 0.001) were more likely to be infected with FeLV. FeLV-infected cats were also more likely to present with anemia (OR 13, p < 0.001) and lymphoma (OR 13.7, p = 0.001). A comparative analysis of the different detection methods in a subset of 109 animals confirmed FeLV infection in 58 cats, including 38 (65.5%) with progressive, 16 (27.6%) with regressive, and 4 (6.9%) with probably focal outcome diseases. In conclusion, this study demonstrates a high prevalence of FeLV in this urban cat population from Brazil and highlights the need to establish more effective prevention strategies (such as viral testing, vaccination programs, specific care for FeLV-positive cats) to reduce diseases associated with this virus in Brazil.
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Affiliation(s)
- Laura Pancich Diesel
- Veterinary Medicine Diagnostic Laboratory (LDMV), Institute of Biotechnology (IB), Postgraduate Programs in Animal Health (PPGSA) and Biotechnology (PPGBIO), University of Caxias do Sul (UCS), Caxias do Sul 95070-560, RS, Brazil; (L.P.D.); (W.d.O.S.); (V.R.Z.B.P.); (A.F.S.)
| | - Lauren Santos de Mello
- Simbios Biotechnologia, Cachoeirinha 94950-000, RS, Brazil; (L.S.d.M.); (N.I.); (A.S.K.F.); (D.K.)
| | - Weslei de Oliveira Santana
- Veterinary Medicine Diagnostic Laboratory (LDMV), Institute of Biotechnology (IB), Postgraduate Programs in Animal Health (PPGSA) and Biotechnology (PPGBIO), University of Caxias do Sul (UCS), Caxias do Sul 95070-560, RS, Brazil; (L.P.D.); (W.d.O.S.); (V.R.Z.B.P.); (A.F.S.)
| | - Nilo Ikuta
- Simbios Biotechnologia, Cachoeirinha 94950-000, RS, Brazil; (L.S.d.M.); (N.I.); (A.S.K.F.); (D.K.)
| | | | - Diéssy Kipper
- Simbios Biotechnologia, Cachoeirinha 94950-000, RS, Brazil; (L.S.d.M.); (N.I.); (A.S.K.F.); (D.K.)
| | - Raquel Redaelli
- Gatices Veterinary Hospital, Caxias do Sul 95000-000, RS, Brazil;
| | - Vagner Reinaldo Zingali Bueno Pereira
- Veterinary Medicine Diagnostic Laboratory (LDMV), Institute of Biotechnology (IB), Postgraduate Programs in Animal Health (PPGSA) and Biotechnology (PPGBIO), University of Caxias do Sul (UCS), Caxias do Sul 95070-560, RS, Brazil; (L.P.D.); (W.d.O.S.); (V.R.Z.B.P.); (A.F.S.)
| | - André Felipe Streck
- Veterinary Medicine Diagnostic Laboratory (LDMV), Institute of Biotechnology (IB), Postgraduate Programs in Animal Health (PPGSA) and Biotechnology (PPGBIO), University of Caxias do Sul (UCS), Caxias do Sul 95070-560, RS, Brazil; (L.P.D.); (W.d.O.S.); (V.R.Z.B.P.); (A.F.S.)
| | - Vagner Ricardo Lunge
- Veterinary Medicine Diagnostic Laboratory (LDMV), Institute of Biotechnology (IB), Postgraduate Programs in Animal Health (PPGSA) and Biotechnology (PPGBIO), University of Caxias do Sul (UCS), Caxias do Sul 95070-560, RS, Brazil; (L.P.D.); (W.d.O.S.); (V.R.Z.B.P.); (A.F.S.)
- Simbios Biotechnologia, Cachoeirinha 94950-000, RS, Brazil; (L.S.d.M.); (N.I.); (A.S.K.F.); (D.K.)
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Moll GM, Swenson CL, Yuzbasiyan-Gurkan V. BET Inhibitor JQ1 Attenuates Feline Leukemia Virus DNA, Provirus, and Antigen Production in Domestic Cat Cell Lines. Viruses 2023; 15:1853. [PMID: 37766260 PMCID: PMC10535802 DOI: 10.3390/v15091853] [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: 08/04/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Feline leukemia virus (FeLV) is a cosmopolitan gammaretrovirus that causes lifelong infections and fatal diseases, including leukemias, lymphomas, immunodeficiencies, and anemias, in domestic and wild felids. There is currently no definitive treatment for FeLV, and while existing vaccines reduce the prevalence of progressive infections, they neither provide sterilizing immunity nor prevent regressive infections that result in viral reservoirs with the potential for reactivation, transmission, and the development of associated clinical diseases. Previous studies of murine leukemia virus (MuLV) established that host cell epigenetic reader bromodomain and extra-terminal domain (BET) proteins facilitate MuLV replication by promoting proviral integration. Here, we provide evidence that this facilitatory effect of BET proteins extends to FeLV. Treatment with the archetypal BET protein bromodomain inhibitor (+)-JQ1 and FeLV challenge of two phenotypically disparate feline cell lines, 81C fibroblasts and 3201 lymphoma cells, significantly reduced FeLV proviral load, total FeLV DNA load, and p27 capsid protein expression at nonlethal concentrations. Moreover, significant decreases in FeLV proviral integration were documented in 81C and 3201 cells. These findings elucidate the importance of BET proteins for efficient FeLV replication, including proviral integration, and provide a potential target for treating FeLV infections.
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Affiliation(s)
- Garrick M. Moll
- Comparative Medicine & Integrative Biology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA;
| | - Cheryl L. Swenson
- Comparative Medicine & Integrative Biology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA;
- Department of Pathobiology & Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Vilma Yuzbasiyan-Gurkan
- Comparative Medicine & Integrative Biology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA;
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
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4
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Economu L, Stell A, O'Neill DG, Schofield I, Stevens K, Brodbelt D. Incidence and risk factors for feline lymphoma in UK primary-care practice. J Small Anim Pract 2020; 62:97-106. [PMID: 33325082 PMCID: PMC7986087 DOI: 10.1111/jsap.13266] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/21/2020] [Accepted: 10/26/2020] [Indexed: 11/29/2022]
Abstract
Objectives The study aimed to estimate the incidence and prevalence of feline lymphoma in cats attending primary‐care practices across the UK and to identify patient‐based and environmental (radon and pesticide exposure) risk factors. Materials and Methods Case records from the VetCompass programme from primary‐care veterinary practices in the UK were searched for a diagnosis of lymphoma in cats in 2016. Cases were required to have had an external laboratory confirmed diagnosis based on cytology and/or histopathology. A nested case–control study design was used to identify risk factors for lymphoma using multivariable logistic regression. Results From a cohort of 562,446 cats under veterinary care at VetCompass participating practices in 2016, a total of 271 lymphoma cases were identified (prevalence: 48/100,000, 95% confidence interval (CI) 44 to 56/100,000; incidence 32/100,000, 95% CI 26 to 35/100,000). There were 180 incident lymphoma cases and 803 controls, all aged 2 years and older. Male (odds ratio (OR) 1.7, 95% CI 1.2 to 2.4), insured (OR 3.6, 95% CI 2.3 to 5.6) and older cats (compared to cats 2 to <5 years, OR 5.0, 95% CI 2.8 to 8.8) were associated with increased odds of lymphoma diagnosis. Vaccinated cats were associated with decreased odds (OR 0.7, 95% CI 0.5 to 1.0) compared to unvaccinated cats, although the type of vaccination received was not statistically significant. Breed and environmental factors studied were not associated with a diagnosis of lymphoma. Clinical Significance This is the first study to estimate the frequency and report risk factors for lymphoma in cats attending UK primary‐care practice.
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Affiliation(s)
- L Economu
- The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts, AL9 7TA, UK
| | - A Stell
- Davies Veterinary Specialists, Manor Farm, Business Park, Higham Gobion, Hitchin, SG5 3HR, UK
| | - D G O'Neill
- Pathobiology and Population Science, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts, AL9 7TA, UK
| | - I Schofield
- Pathobiology and Population Science, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts, AL9 7TA, UK
| | - K Stevens
- Pathobiology and Population Science, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts, AL9 7TA, UK
| | - D Brodbelt
- Pathobiology and Population Science, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts, AL9 7TA, UK
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Hartmann K, Hofmann-Lehmann R. What's New in Feline Leukemia Virus Infection. Vet Clin North Am Small Anim Pract 2020; 50:1013-1036. [PMID: 32680664 DOI: 10.1016/j.cvsm.2020.05.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Feline leukemia virus (FeLV) is a retrovirus with global impact on the health of domestic cats that causes tumors (mainly lymphoma), bone marrow disorders, and immunosuppression. The importance of FeLV is underestimated due to complacency associated with previous decline in prevalence. However, with this comes lowered vigilance, which, along with potential for regressively infected cats to reactivate viremia and shed the virus or develop clinical signs, can pose a risk to feline health. This article summarizes knowledge on FeLV pathogenesis, courses of infection, and factors affecting prevalance, infection outcome, and development of FeLV-associated diseases, with special focus on regressive FeLV infection.
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Affiliation(s)
- Katrin Hartmann
- Clinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine LMU Munich, Veterinaerstrasse 13, Munich 80539, Germany.
| | - Regina Hofmann-Lehmann
- Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, Zurich 8057, Switzerland
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Grosenbaugh DA, Frances-Duvert V, Abedi S, Feilmeier B, Ru H, Poulet H. Efficacy of a nonadjuvanted recombinant FeLV vaccine and two inactivated FeLV vaccines when subject to consistent virulent FeLV challenge conditions. Biologicals 2017; 49:76-80. [PMID: 28734742 DOI: 10.1016/j.biologicals.2016.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/19/2016] [Accepted: 10/17/2016] [Indexed: 11/25/2022] Open
Abstract
The purpose of this study was to compare the efficacy of three FeLV vaccines, under identical conditions in a laboratory challenge model that closely mimics natural infection. Four groups of cats (n = 20 per group) were administered two doses of vaccine, 21 days apart, starting at 9-10 weeks of age (Purevax® FeLV, Versifel® FeLV, Nobivac® feline 2-FeLV, and a placebo). Cats were challenged 3 weeks later with a virulent, heterologous FeLV isolate. FeLV antigenemia was determined at weekly intervals from 3 to 15 weeks postchallenge. Circulating proviral DNA was determined on terminal PBMC samples. Following challenge, persistent antigenemia developed in 15 (75%) placebo-vaccinated cats, 3 (15%) cats in the Versifel FeLV vaccinated group, and 1 cat (5%) each in the Purevax FeLV and the Nobivac FeLV vaccinated groups. The prevented fractions for three vaccine groups were 93%, 93%, and 80% respectively. The adjusted p-values for all vaccine group comparisons fail to approach statistical significance. There was excellent agreement between proviral FeLV DNA in circulating PBMCs and persistent antigenemia. It is shown that when cats are managed under the same conditions during a virulent challenge, via the normal route of infection, the tested vaccines all show a comparable degree of protection.
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Affiliation(s)
| | - Valérie Frances-Duvert
- Merial, Research and Development, Lyon Gerland Laboratories, 254 rue Marcel Mérieux, 69007, Lyon, France
| | - Shabnam Abedi
- Merial, Research and Development, 1730 Olympic Dr., Athens, GA 30601, USA
| | - Bradley Feilmeier
- Merial, Research and Development, 1730 Olympic Dr., Athens, GA 30601, USA
| | - Hongyu Ru
- Merial, Research and Development, 1730 Olympic Dr., Athens, GA 30601, USA
| | - Hervé Poulet
- Merial, Research and Development, Lyon Gerland Laboratories, 254 rue Marcel Mérieux, 69007, Lyon, France
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7
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Comparative Efficacy of Feline Leukemia Virus (FeLV) Inactivated Whole-Virus Vaccine and Canarypox Virus-Vectored Vaccine during Virulent FeLV Challenge and Immunosuppression. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:798-805. [PMID: 25972402 PMCID: PMC4478526 DOI: 10.1128/cvi.00034-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/22/2015] [Indexed: 11/24/2022]
Abstract
Four vaccines for feline leukemia virus (FeLV) are available in the United States. This study's purpose was to compare the efficacy of Nobivac feline 2-FeLV (an inactivated, adjuvanted whole-virus vaccine) and PureVax recombinant FeLV (a live, canarypox virus-vectored vaccine) following FeLV challenge. Cats were vaccinated at 9 and 12 weeks with Nobivac feline 2-FeLV (group A, n = 11) or PureVax recombinant FeLV (group B, n = 10). Group C (n = 11) comprised unvaccinated controls. At 3 months postvaccination, cats were immunosuppressed and challenged with FeLV-A/61E. The outcomes measured were persistent antigenemia at 12 weeks postchallenge (PC) and proviral DNA and viral RNA at 3 to 9 weeks PC. Persistent antigenemia was observed in 0 of 11 cats in group A, 5 of 10 cats in group B, and 10 of 11 cats in group C. Group A was significantly protected compared to those in groups B (P < 0.013) and C (P < 0.0001). No difference was found between groups B and C (P > 0.063). The preventable fraction was 100% for group A and 45% for group B. At 9 weeks PC, proviral DNA and viral RNA were detected 1 of 11 cats in group A, 6 of 10 cats in group B, and 9 of 11 cats in group C. Nucleic acid loads were significantly lower in group A than in group C (P < 0.01). Group A had significantly lower proviral DNA loads than group B at weeks 6 to 9 (P < 0.02). The viral RNA loads were significantly lower in group A than in group B at weeks 7 to 9 (P < 0.01). The results demonstrate that Nobivac feline 2-FeLV-vaccinated cats were fully protected against persistent antigenemia and had significantly smaller amounts of proviral DNA and plasma viral RNA loads than PureVax recombinant FeLV-vaccinated cats and unvaccinated controls.
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Helfer-Hungerbuehler AK, Widmer S, Kessler Y, Riond B, Boretti FS, Grest P, Lutz H, Hofmann-Lehmann R. Long-term follow up of feline leukemia virus infection and characterization of viral RNA loads using molecular methods in tissues of cats with different infection outcomes. Virus Res 2015; 197:137-50. [DOI: 10.1016/j.virusres.2014.12.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 10/24/2022]
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Molecular detection, phylogenetic analysis, and identification of transcription motifs in feline leukemia virus from naturally infected cats in malaysia. Vet Med Int 2014; 2014:760961. [PMID: 25506469 PMCID: PMC4251355 DOI: 10.1155/2014/760961] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/11/2014] [Accepted: 09/11/2014] [Indexed: 01/14/2023] Open
Abstract
A nested PCR assay was used to determine the viral RNA and proviral DNA status of naturally infected cats. Selected samples that were FeLV-positive by PCR were subjected to sequencing, phylogenetic analysis, and motifs search. Of the 39 samples that were positive for FeLV p27 antigen, 87.2% (34/39) were confirmed positive with nested PCR. FeLV proviral DNA was detected in 38 (97.3%) of p27-antigen negative samples. Malaysian FeLV isolates are found to be highly similar with a homology of 91% to 100%. Phylogenetic analysis revealed that Malaysian FeLV isolates divided into two clusters, with a majority (86.2%) sharing similarity with FeLV-K01803 and fewer isolates (13.8%) with FeLV-GM1 strain. Different enhancer motifs including NF-GMa, Krox-20/WT1I-del2, BAF1, AP-2, TBP, TFIIF-beta, TRF, and TFIID are found to occur either in single, duplicate, triplicate, or sets of 5 in different positions within the U3-LTR-gag region. The present result confirms the occurrence of FeLV viral RNA and provirus DNA in naturally infected cats. Malaysian FeLV isolates are highly similar, and a majority of them are closely related to a UK isolate. This study provides the first molecular based information on FeLV in Malaysia. Additionally, different enhancer motifs likely associated with FeLV related pathogenesis have been identified.
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Kim WS, Chong CK, Kim HY, Lee GC, Jeong W, An DJ, Jeoung HY, Lee JI, Lee YK. Development and clinical evaluation of a rapid diagnostic kit for feline leukemia virus infection. J Vet Sci 2013; 15:91-7. [PMID: 24136209 PMCID: PMC3973770 DOI: 10.4142/jvs.2014.15.1.91] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 07/09/2013] [Indexed: 11/20/2022] Open
Abstract
Feline leukemia virus (FeLV) causes a range of neoplastic and degenerative diseases in cats. To obtain a more sensitive and convenient diagnosis of the disease, we prepared monoclonal antibodies specific for the FeLV p27 to develop a rapid diagnostic test with enhanced sensitivity and specificity. Among these antibodies, we identified two clones (hybridomas 8F8B5 and 8G7D1) that specifically bound to FeLV and were very suitable for a diagnostic kit. The affinity constants for 8F8B5 and 8G7D1 were 0.35 × 109 and 0.86 × 109, respectively. To investigate the diagnostic abilities of the rapid kit using these antibodies, we performed several clinical studies. Assessment of analytical sensitivity revealed that the detection threshold of the rapid diagnostic test was 2 ng/mL for recombinant p27 and 12.5 × 104 IU/mL for FeLV. When evaluating 252 cat sera samples, the kit was found to have a kappa value of 0.88 compared to polymerase chain reaction (PCR), indicating a significant correlation between data from the rapid diagnostic test and PCR. Sensitivity and specificity of the kit were 95.2% (20/21) and 98.5% (257/261), respectively. Our results demonstrated that the rapid diagnostic test would be a suitable diagnostic tool for the rapid detection of FeLV infection in cats.
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Affiliation(s)
- Won-Shik Kim
- Department of Clinical Pathology Laboratory Science, Daejeon Health Science College, Daejeon 300-711, Korea
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11
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GAPDH Pseudogenes and the Quantification of Feline Genomic DNA Equivalents. Mol Biol Int 2013; 2013:587680. [PMID: 23738070 PMCID: PMC3655645 DOI: 10.1155/2013/587680] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/21/2013] [Accepted: 03/28/2013] [Indexed: 01/14/2023] Open
Abstract
Quantitative real-time PCR (qPCR) is broadly used to detect and quantify nucleic acid targets. In order to determine cell copy number and genome equivalents, a suitable reference gene that is present in a defined number in the genome is needed, preferably as a single copy gene. For most organisms, a variable number of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) pseudogenes have been reported. However, it has been suggested that a single-copy of the GAPDH pseudogene is present in the feline genome and that a GAPDH assay can therefore be used to quantify feline genomic DNA (gDNA). The aim of this study was to determine whether one or more GAPDH pseudogenes are present in the feline genome and to provide a suitable alternative qPCR system for the quantification of feline cell copy number and genome equivalents. Bioinformatics and sequencing results revealed that not just one but several closely related GAPDH-like sequences were present in the cat genome. We thus identified, developed, optimized, and validated an alternative reference gene assay using feline albumin (fALB). Our data emphasize the need for an alternative reference gene, apart from the GAPDH pseudogene, for the normalization of gDNA levels. We recommend using the fALB qPCR assay for future studies.
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Abstract
Extremophiles can be defined as organisms that can survive in extreme environments that cannot support mammalian life. They include microorganisms that can tolerate temperature extremes, extremes of pH, salinity, hydrostatic pressure and ionizing radiation, as well as low oxygen tension, desiccation and the presence of heavy metals. Psychrophilic organisms also include fish in polar waters and animals that withstand freezing. Rare examples of thermophilic pathogens exist, and the main category of extremophilic animal pathogens comprises psychrophilic and psychrotrophic microorganisms that cause fish diseases, e.g. Flavobacterium psychrophilum, Moritella viscosa, Aliivibrio wodanis and Aliivibrio salmonicida. The most widely known application of an extremophile product in veterinary medicine is DNA polymerase from thermophiles, which is a mainstay of PCR-based diagnostics for an extensive range of animal pathogens. DNA polymerases and other extremophile enzymes are also used in many molecular biology applications and animal genomics. Other extremophile products may find application in veterinary medicine in the future. These include enzymes in biosensors, compatible solutes in skin care products, drug excipients, treatments for respiratory disease, radioprotectants, peptide antibiotics, archaeal lipids for drug delivery and anti-cancer therapeutics.
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Affiliation(s)
- Jane Ann Irwin
- Veterinary Sciences Centre, UCD School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
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Helfer-Hungerbuehler AK, Cattori V, Boretti FS, Ossent P, Grest P, Reinacher M, Henrich M, Bauer E, Bauer-Pham K, Niederer E, Holznagel E, Lutz H, Hofmann-Lehmann R. Dominance of highly divergent feline leukemia virus A progeny variants in a cat with recurrent viremia and fatal lymphoma. Retrovirology 2010; 7:14. [PMID: 20167134 PMCID: PMC2837606 DOI: 10.1186/1742-4690-7-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Accepted: 02/19/2010] [Indexed: 12/30/2022] Open
Abstract
Background In a cat that had ostensibly recovered from feline leukemia virus (FeLV) infection, we observed the reappearance of the virus and the development of fatal lymphoma 8.5 years after the initial experimental exposure to FeLV-A/Glasgow-1. The goals of the present study were to investigate this FeLV reoccurrence and molecularly characterize the progeny viruses. Results The FeLV reoccurrence was detected by the presence of FeLV antigen and RNA in the blood and saliva. The cat was feline immunodeficiency virus positive and showed CD4+ T-cell depletion, severe leukopenia, anemia and a multicentric monoclonal B-cell lymphoma. FeLV-A, but not -B or -C, was detectable. Sequencing of the envelope gene revealed three FeLV variants that were highly divergent from the virus that was originally inoculated (89-91% identity to FeLV-A/Glasgow-1). In the long terminal repeat 31 point mutations, some previously described in cats with lymphomas, were detected. The FeLV variant tissue provirus and viral RNA loads were significantly higher than the FeLV-A/Glasgow-1 loads. Moreover, the variant loads were significantly higher in lymphoma positive compared to lymphoma negative tissues. An increase in the variant provirus blood load was observed at the time of FeLV reoccurrence. Conclusions Our results demonstrate that ostensibly recovered FeLV provirus-positive cats may act as a source of infection following FeLV reactivation. The virus variants that had largely replaced the inoculation strain had unusually heavily mutated envelopes. The mutations may have led to increased viral fitness and/or changed the mutagenic characteristics of the virus.
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Sainsus N, Cattori V, Lepadatu C, Hofmann-Lehmann R. Liquid culture medium for the rapid cultivation of Helicobacter pylori from biopsy specimens. Eur J Clin Microbiol Infect Dis 2008; 27:1209-17. [PMID: 18604574 DOI: 10.1007/s10096-008-0567-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 05/29/2008] [Indexed: 01/06/2023]
Abstract
The goal of this study was to develop a liquid culture medium for the rapid isolation, cultivation, identification and subsequent antibiotics susceptibility testing of Helicobacter pylori directly from biopsy specimens. Five liquid media were tested: Ham's F-12, Brucella broth, tryptic soybroth, brain heart infusion broth and Mueller-Hinton broth. After optimisation of the medium, it was applied in order to investigate biopsy samples from 150 patients with gastro-duodenal disorders and compared with traditional culture methods, microscopy and an H. pylori-specific TaqMan real-time polymerase chain reaction (PCR). The most reliable and rapid growth of H. pylori, even at a small inoculum size, was obtained in Ham's F-12 medium with 5% horse serum. The developed system allowed the primary isolation of H. pylori in clinical samples and provided 87% sensitivity and 100% specificity.
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Affiliation(s)
- N Sainsus
- Department of Microbiology, State University of Medicine and Pharmacy N. Testemiţanu, 165, bd. Stefan cel Mare si Sfint, 2004, Chishinau, Moldova.
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