scholarly journals Detection of Avian Influenza Virus of H9 Subtype in the Faeces of Experimentally and Naturally Infected Chickens by Reverse Transcription-Polymerase Chain Reaction

2007 ◽  
Vol 76 (3) ◽  
pp. 405-413 ◽  
Author(s):  
H. Noroozian ◽  
M. Vasfi Marandi ◽  
M. Razazian
Keyword(s):  
Polymerase Chain Reaction ◽  
Avian Influenza ◽  
Reverse Transcription ◽  
Predictive Value ◽  
Relative Sensitivity ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Diagnostic Laboratory ◽  
Polymerase Chain ◽  
Virus Subtype

Avian Influenza (AI) is a viral, highly contagious disease of domestic and wild birds. In an avian diagnostic laboratory, it is essential to have methods for rapid detection of respiratory viruses. In the present study, cloacal swabs collected from chickens experimentally and naturally infected with mild pathogenicity AI virus subtype H9, used in a reverse transcription-polymerase chain reaction (RTPCR) assay for detection of AI. On cloacal swabs collected from experimentally infected chickens, AI virus was detected most frequently between days 3 and 7 post infection (p.i.) and the relative sensitivity, specificity, correlation rate, positive predictive value and negative predictive value of the RT-PCR compared to virus isolation (VI) assay were 84%, 80%, 82%, 83% and 81%, respectively. On pooled cloacal swabs collected from flocks suspected of AI, these results were 96%, 100%, 97%, 83% and 100%, respectively. The results proved that the RT-PCR assay could be a reliable and rapid alternative to VI assay for detection of AI virus subtype H9 in faecal specimens.

scholarly journals Evaluation of a 384–Well Format for High-Throughput Real-Time Reverse Transcription Polymerase Chain Reaction for Avian Influenza Testing

2009 ◽  
Vol 21 (5) ◽  
pp. 679-683 ◽  
Author(s):  
Pamela J. Ferro ◽  
Jason Osterstock ◽  
Bo Norby ◽  
Geoffrey T. Fosgate ◽  
Blanca Lupiani
Keyword(s):  
Polymerase Chain Reaction ◽  
Avian Influenza ◽  
Real Time ◽  
High Throughput ◽  
Reverse Transcription ◽  
Virus Isolation ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Response Planning ◽  
Polymerase Chain

As concerns over the global spread of highly pathogenic avian influenza H5N1 have heightened, more countries are faced with increased surveillance efforts and incident response planning for handling a potential outbreak. The incorporation of molecular techniques in most diagnostic laboratories has enabled fast and efficient testing of many agents of concern, including avian influenza. However, the need for high-throughput testing remains. In this study, the use of a 384–well format for high-throughput real-time reverse transcription polymerase chain reaction (real-time RT-PCR) testing for avian influenza is described. The analytical sensitivity of a real-time RT-PCR assay for avian influenza virus matrix gene with the use of both 96– and 384–well assay formats and serial dilutions of transcribed control RNA were comparable, resulting in similar limits of detection. Of 28 hunter-collected cloacal swabs that were positive by virus isolation, 26 (92.9%) and 27 (96.4%) were positive in the 96– and 384–well assays, respectively; of the 340 hunter-collected swabs that were negative by virus isolation, 45 (13.2%) and 23 (6.8%) were positive in the 96– and 384–well assays, respectively. The data presented herein supports the utility of the 384–well format in the event of an avian influenza outbreak for high-throughput real-time RT-PCR testing.

scholarly journals Detecting SARS-CoV-2 at point of care: preliminary data comparing loop-mediated isothermal amplification (LAMP) to polymerase chain reaction (PCR)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Marc F. Österdahl ◽  
Karla A. Lee ◽  
Mary Ni Lochlainn ◽  
Stuart Wilson ◽  
Sam Douthwaite ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcription ◽  
Predictive Value ◽  
Point Of Care ◽  
Isothermal Amplification ◽  
Service Improvement ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Loop Mediated Isothermal Amplification ◽  
Polymerase Chain

Abstract Background A cost effective and efficient diagnostic tool for COVID-19 as near to the point of care (PoC) as possible would be a game changer in the current pandemic. We tested reverse transcription loop mediated isothermal amplification (RT-LAMP), a method which can produce results in under 30 min, alongside standard methods in a real-life clinical setting. Methods This prospective service improvement project piloted an RT-LAMP method on nasal and pharyngeal swabs on 21 residents of a high dependency care home, with two index COVID-19 cases, and compared it to multiplex tandem reverse transcription polymerase chain reaction (RT-PCR). We recorded vital signs of patients to correlate clinical and laboratory information and calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of a single swab using RT-LAMP compared with the current standard, RT-PCR, as per Standards for Reporting Diagnostic Accuracy Studies (STARD) guidelines. Results The novel method accurately detected 8/10 RT-PCR positive cases and identified a further 3 positive cases. Eight further cases were negative using both methods. Using repeated RT-PCR as a “gold standard”, the sensitivity and specificity of a single novel test were 80 and 73% respectively. PPV was 73% and NPV was 83%. Incorporating retesting of low signal RT-LAMP positives improved the specificity to 100%. We also speculate that hypothermia may be a significant early clinical sign of COVID-19. Conclusions RT-LAMP testing for SARS-CoV-2 was found to be promising, fast and to work equivalently to RT-PCR methods. RT-LAMP has the potential to transform COVID-19 detection, bringing rapid and accurate testing to the PoC. RT-LAMP could be deployed in mobile community testing units, care homes and hospitals to detect disease early and prevent spread.

LOW SPECIFICITY OF A NESTED REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION TO DETECT AVIAN INFLUENZA VIRUS NUCLEOPROTEIN GENE

2016 ◽  
Vol 43 (02) ◽  
pp. 75-79
Author(s):  
Lih-Chiann Wang ◽  
Wei-En Hsu ◽  
Wei Thong ◽  
Ting-Yen Chao ◽  
Ching-Ho Wang
Keyword(s):  
Polymerase Chain Reaction ◽  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Reverse Transcription ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Nucleoprotein Gene ◽  
Polymerase Chain ◽  
Np Gene

Reverse transcription polymerase chain reaction (RT-PCR) was used routinely to detect the avian influenza virus (AIV) nucleoprotein (NP) gene. The purpose of the present study was to compare the correctness of a nested RT-PCR (nRT-PCR), one conventional RT-PCR with its outer primer (oRT-PCR) and the other conventional RT-PCR with its inner primer (iRT-PCR) to detect AIV NP gene. A total of 365 AI-free fecal swabs (73 pools), 7 tracheal swabs and anllantoic fluid from 25 chicken embryos were used to determine the analytic specificities of those tests. Compared with the iRT-PCR, the nRT-PCR was more sensitive for AIV detection. However, the specificities of nRT-PCR, oRT-PCR and iRT-PCR were 48.6% (35/72), 100% (67/67) and 91.3% (84/92), respectively. The amplifying band was sequenced and confirmed to be the AIV NP gene as the positive control. The specificity of this nRT-PCR is too low to be used for the AIV screening test.

Single-Step Multiplex Reverse Transcription–Polymerase Chain Reaction (RT-PCR) for Influenza A Virus Subtype H5N1 Detection

2004 ◽  
Vol 17 (4) ◽  
pp. 588-593 ◽  
Author(s):  
Sunchai Payungporn ◽  
Piraya Phakdeewirot ◽  
Salin Chutinimitkul ◽  
Apiradee Theamboonlers ◽  
Juthatip Keawcharoen ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Influenza A Virus ◽  
Reverse Transcription ◽  
Influenza A ◽  
Single Step ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Virus Subtype

1504: Molecular Diagnosis and Staging of Prostate Cancer Using Clusterin in Real Time Reverse Transcription Polymerase Chain Reaction (RT-PCR)

2006 ◽  
Vol 175 (4S) ◽  
pp. 485-486
Author(s):  
Sabarinath B. Nair ◽  
Christodoulos Pipinikas ◽  
Roger Kirby ◽  
Nick Carter ◽  
Christiane Fenske
Keyword(s):  
Prostate Cancer ◽  
Polymerase Chain Reaction ◽  
Real Time ◽  
Molecular Diagnosis ◽  
Reverse Transcription ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain

scholarly journals A meta-analysis of accuracy and sensitivity of chest CT and RT-PCR in COVID-19 diagnosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fatemeh Khatami ◽  
Mohammad Saatchi ◽  
Seyed Saeed Tamehri Zadeh ◽  
Zahra Sadat Aghamir ◽  
Alireza Namazi Shabestari ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Ct Scan ◽  
Predictive Value ◽  
Meta Analysis ◽  
Chest Ct ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Chest Ct Scan

AbstractNowadays there is an ongoing acute respiratory outbreak caused by the novel highly contagious coronavirus (COVID-19). The diagnostic protocol is based on quantitative reverse-transcription polymerase chain reaction (RT-PCR) and chests CT scan, with uncertain accuracy. This meta-analysis study determines the diagnostic value of an initial chest CT scan in patients with COVID-19 infection in comparison with RT-PCR. Three main databases; PubMed (MEDLINE), Scopus, and EMBASE were systematically searched for all published literature from January 1st, 2019, to the 21st May 2020 with the keywords "COVID19 virus", "2019 novel coronavirus", "Wuhan coronavirus", "2019-nCoV", "X-Ray Computed Tomography", "Polymerase Chain Reaction", "Reverse Transcriptase PCR", and "PCR Reverse Transcriptase". All relevant case-series, cross-sectional, and cohort studies were selected. Data extraction and analysis were performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5. Among 1022 articles, 60 studies were eligible for totalizing 5744 patients. The overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan compared to RT-PCR were 87% (95% CI 85–90%), 46% (95% CI 29–63%), 69% (95% CI 56–72%), and 89% (95% CI 82–96%), respectively. It is important to rely on the repeated RT-PCR three times to give 99% accuracy, especially in negative samples. Regarding the overall diagnostic sensitivity of 87% for chest CT, the RT-PCR testing is essential and should be repeated to escape misdiagnosis.

Expression of hyaluronan synthase-3 in porcine oviducal epithelium during oestrus

2003 ◽  
Vol 15 (2) ◽  
pp. 99 ◽  
Author(s):  
Paisan Tienthai ◽  
Naoko Kimura ◽  
Paraskevi Heldin ◽  
Eimei Sato ◽  
Heriberto Rodriguez-Martinez
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcription ◽  
Hyaluronan Synthase ◽  
Critical Periods ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Mean Values ◽  
Polymerase Chain ◽  
Sperm Reservoir ◽  
Oviduct Fluid

Hyaluronan (HA) has been related to fertilization and embryo development in the pig. Furthermore, HA is present in pig oviduct fluid and the lining epithelium, particularly of the pre-ovulatory sperm reservoir. Because the mechanisms that regulate HA synthesis have not yet been clarified, semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was conducted to assess the expression of mRNAs of two HA-synthesizing enzymes (has2 and has3) in the oviduct epithelium (uterotubal junction, isthmus, ampullary–isthmic junction and ampulla segments) of non-inseminated (control) and inseminated (treatment) sows at pre-, peri- and post-ovulatory oestrus. Only has3 mRNA was detected; it was present in all tubal segments of both control and treatment samples. The level of has3 expression did not vary significantly between non-inseminated and inseminated specimens, but there was a tendency (NS) for increased mean values during the peri- and post-ovulatory stages compared with pre-ovulation. It is concluded that has3 is expressed by the porcine endosalpinx epithelium and the levels of expression do not vary during the critical periods of sperm transport and fertilization, despite fluctuating levels of HA in the tubal fluid at corresponding periods.

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