Quantification of endogenous and exogenous feline leukemia virus sequences by real-time PCR assays

ABSTRACTQuantitative real-time PCR (qPCR) is increasingly being used for the detection of bovine leukemia virus (BLV) proviral DNA. Nevertheless, quality control for the validation and standardization of such tests is currently lacking. Therefore, the present study was initiated by three Office International des Epizooties (OIE) reference laboratories and three collaborating laboratories to measure the interlaboratory variability of six already developed and available BLV qPCR assays. For that purpose, an international panel of 58 DNA samples reflecting the dynamic range of the majority of the assays was distributed to six testing centers. Based on qualitative results, the overall agreement among all six laboratories was moderate. However, significant variability in the measurement of the BLV proviral DNA copy number was observed among different laboratories. Quantitative PCR assays, even when performed by experienced staff, can yield large variability in BLV proviral DNA copy numbers without harmonization. Further standardization of different factors (i.e., utilization of unified protocols and unique calibrators) should increase interlaboratory agreement.

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Development and application of a quantitative real-time PCR assay to detect feline leukemia virus RNA

Veterinary Immunology and Immunopathology ◽

10.1016/j.vetimm.2008.01.013 ◽

2008 ◽

Vol 123 (1-2) ◽

pp. 81-89 ◽

Cited By ~ 14

Author(s):

Andrea N. Torres ◽

Kevin P. O’Halloran ◽

Laurie J. Larson ◽

Ronald D. Schultz ◽

Edward A. Hoover

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Leukemia Virus ◽

Feline Leukemia Virus ◽

Quantitative Real Time Pcr ◽

Pcr Assay ◽

Virus Rna

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Real-time PCR investigation of feline leukemia virus proviral and viral RNA loads in leukocyte subsets

Veterinary Immunology and Immunopathology ◽

10.1016/j.vetimm.2008.01.018 ◽

2008 ◽

Vol 123 (1-2) ◽

pp. 124-128 ◽

Cited By ~ 17

Author(s):

Valentino Cattori ◽

Andrea C. Pepin ◽

Ravi Tandon ◽

Barbara Riond ◽

Marina L. Meli ◽

...

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Leukemia Virus ◽

Viral Rna ◽

Feline Leukemia Virus

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Re-examination of feline leukemia virus: host relationships using real-time PCR

Virology ◽

10.1016/j.virol.2004.10.050 ◽

2005 ◽

Vol 332 (1) ◽

pp. 272-283 ◽

Cited By ~ 62

Author(s):

Andrea N. Torres ◽

Candace K. Mathiason ◽

Edward A. Hoover

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Leukemia Virus ◽

Feline Leukemia Virus ◽

Host Relationships

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Gammaretrovirus-Specific Antibodies in Free-Ranging and Captive Namibian Cheetahs

Clinical and Vaccine Immunology ◽

10.1128/cvi.00705-14 ◽

2015 ◽

Vol 22 (6) ◽

pp. 611-617 ◽

Cited By ~ 5

Author(s):

Annika Krengel ◽

Valentino Cattori ◽

Marina L. Meli ◽

Bettina Wachter ◽

Jürg Böni ◽

...

Keyword(s):

Reverse Transcriptase ◽

Real Time ◽

Real Time Pcr ◽

Mononuclear Cells ◽

Leukemia Virus ◽

Reverse Transcriptase Activity ◽

Feline Leukemia Virus ◽

Quantitative Real Time Pcr ◽

Peripheral Blood Mononuclear ◽

Free Ranging

ABSTRACTThe cheetah population in Namibia is the largest free-ranging population in the world and a key population for research regarding the health status of this species. We used serological methods and quantitative real-time PCR to test free-ranging and captive Namibian cheetahs for the presence of feline leukemia virus (FeLV), a gammaretrovirus that can be highly aggressive in populations with low genetic diversity, such as cheetahs. We also assessed the presence of antibodies to other gammaretroviruses and the responses to a FeLV vaccine developed for domestic cats. Up to 19% of the free-ranging cheetahs, 27% of the captive nonvaccinated cheetahs, and 86% of the captive vaccinated cheetahs tested positive for FeLV antibodies. FeLV-antibody-positive free-ranging cheetahs also tested positive for Rauscher murine leukemia virus antibodies. Nevertheless, FeLV was not detectable by quantitative real-time PCR and no reverse transcriptase activity was detectable by product-enhanced reverse transcriptase assay in the plasma of cheetahs or the supernatants from cultures of peripheral blood mononuclear cells. The presence of antibodies to gammaretroviruses in clinically healthy specimens may be caused either by infection with a low-pathogenic retrovirus or by the expression of endogenous retroviral sequences. The strong humoral immune responses to FeLV vaccination demonstrate that cheetahs can respond to the vaccine and that vaccination against FeLV infection may be beneficial should FeLV infection ever become a threat, as was seen in Iberian lynx and Florida panthers.

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DEVELOPMENT OF MULTIPLEX REAL-TIME PCR ASSAY FOR SIX PATHOGENS: RAPID TOOL FOR DIAGNOSIS OF BACTERIAL MENINGITIS

Journal of Medicine and Pharmacy ◽

10.34071/jmp.2019.3.8 ◽

2019 ◽

pp. 60-66

Author(s):

Viet Quynh Tram Ngo ◽

Thi Ti Na Nguyen ◽

Hoang Bach Nguyen ◽

Thi Tuyet Ngoc Tran ◽

Thi Nam Lien Nguyen ◽

...

Keyword(s):

Bacterial Meningitis ◽

Real Time ◽

Real Time Pcr ◽

Diagnostic Methods ◽

Type B ◽

E Coli ◽

Pcr Assays ◽

Set Up ◽

Etiological Agents ◽

Suis Serotype

Introduction: Bacterial meningitis is an acute central nervous infection with high mortality or permanent neurological sequelae if remained undiagnosed. However, traditional diagnostic methods for bacterial meningitis pose challenge in prompt and precise identification of causative agents. Aims: The present study will therefore aim to set up in-house PCR assays for diagnosis of six pathogens causing the disease including H. influenzae type b, S. pneumoniae, N. meningitidis, S. suis serotype 2, E. coli and S. aureus. Methods: inhouse PCR assays for detecting six above-mentioned bacteria were optimized after specific pairs of primers and probes collected from the reliable literature resources and then were performed for cerebrospinal fluid (CSF) samples from patients with suspected meningitis in Hue Hospitals. Results: The set of four PCR assays was developed including a multiplex real-time PCR for S. suis serotype 2, H. influenzae type b and N. meningitides; three monoplex real-time PCRs for E. coli, S. aureus and S. pneumoniae. Application of the in-house PCRs for 116 CSF samples, the results indicated that 48 (39.7%) cases were positive with S. suis serotype 2; one case was positive with H. influenzae type b; 4 cases were positive with E. coli; pneumococcal meningitis were 19 (16.4%) cases, meningitis with S. aureus and N. meningitidis were not observed in any CSF samples in this study. Conclusion: our in-house real-time PCR assays are rapid, sensitive and specific tools for routine diagnosis to detect six mentioned above meningitis etiological agents. Key words: Bacterial meningitis, etiological agents, multiplex real-time PCR

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Faculty Opinions recommendation of Evaluation of conventional and real-time PCR assays using two targets for confirmation of results of the COBAS AMPLICOR Chlamydia trachomatis/Neisseria gonorrhoeae test for detection of Neisseria gonorrhoeae in clinical samples.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1025709.374387 ◽

2006 ◽

Author(s):

David Persing

Keyword(s):

Chlamydia Trachomatis ◽

Neisseria Gonorrhoeae ◽

Real Time ◽

Real Time Pcr ◽

Clinical Samples ◽

Pcr Assays

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Faculty Opinions recommendation of Comparison of real-time PCR assays for monitoring serum hepatitis B virus DNA levels during antiviral therapy.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1040569.489566 ◽

2006 ◽

Author(s):

David Persing

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Antiviral Therapy ◽

Real Time ◽

Real Time Pcr ◽

Serum Hepatitis ◽

Hepatitis B Virus Dna ◽

B Virus ◽

Pcr Assays

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Differing Effects of Standard and Harsh Nucleic Acid Extraction Procedures on Diagnostic Helminth Real-Time PCRs Applied to Human Stool Samples

Pathogens ◽

10.3390/pathogens10020188 ◽

2021 ◽

Vol 10 (2) ◽

pp. 188

Author(s):

Tanja Hoffmann ◽

Andreas Hahn ◽

Jaco J. Verweij ◽

Gérard Leboulle ◽

Olfert Landt ◽

...

Keyword(s):

Nucleic Acid ◽

Real Time ◽

Real Time Pcr ◽

Acid Extraction ◽

Nucleic Acid Extraction ◽

Pcr Assay ◽

Bead Beating ◽

Stool Samples ◽

Pcr Assays ◽

Human Stool

This study aimed to assess standard and harsher nucleic acid extraction schemes for diagnostic helminth real-time PCR approaches from stool samples. A standard procedure for nucleic acid extraction from stool and a procedure including bead-beating as well as proteinase K digestion were compared with group-, genus-, and species-specific real-time PCR assays targeting helminths and nonhelminth pathogens in human stool samples. From 25 different in-house and commercial helminth real-time PCR assays applied to 77 stool samples comprising 67 historic samples and 10 external quality assessment scheme samples positively tested for helminths, higher numbers of positive test results were observed after bead-beating-based nucleic acid extraction for 5/25 (20%) real-time PCR assays irrespective of specificity issues. Lower cycle threshold values were observed for one real-time PCR assay after the standard extraction scheme, and for four assays after the bead-beating-based scheme. Agreement between real-time PCR results after both nucleic acid extraction strategies according to Cohen’s kappa ranged from poor to almost perfect for the different assays. Varying agreement was observed in eight nonhelminth real-time PCR assays applied to 67 historic stool samples. The study indicates highly variable effects of harsh nucleic acid extraction approaches depending on the real-time PCR assay used.

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