scholarly journals Fast, Sensitive and Specific Detection of Thailand orthohantavirus and its Variants Using One-Step Real-Time Reverse-Transcription Polymerase Chain Reaction Assay

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 718
Author(s):  
Vololoniaina Raharinosy ◽  
Jean-Michel Heraud ◽  
Harinirina Aina Rabemananjara ◽  
Sandra Telfer ◽  
Danielle Aurore Doll Rakoto ◽  
...  

Genetic variants of Thailand orthohantavirus (THAIV) have been recently reported from rodents in South-East Asia and in islands from the South-West part of the Indian Ocean. In order to detect THAIV and its variants, we developed a sensitive and specific real-time RT-PCR targeting the S segment. Our assay was developed in two different RT-PCR systems that gave similar results in terms of sensitivity. Moreover, our results demonstrated a specificity of 100%.

Author(s):  
Choon Mee Kim ◽  
Dong-Min Kim ◽  
Na-Ra Yun

Severe fever with thrombocytopenia syndrome (SFTS), caused by SFTS virus (SFTSV) is an emerging tick-borne infectious disease. Few studies have assessed the clinical usefulness of nested reverse-transcription polymerase chain reaction (RT-PCR) for diagnosing SFTS. We performed conventional RT-PCR targeting the M segment, nested RT-PCR targeting M and S segments, and real-time RT-PCR targeting the S segment of SFTSV for four patients with suspected SFTS. Although conventional RT-PCR results for the first two patients were negative at admission, nested RT-PCR using the S or M targets was positive for the same samples. Likewise, in the other two patients, initial samples were confirmed positive in all three tests, but follow-up testing demonstrated negative conventional RT-PCR and positive nested RT-PCR results. Thus, delayed testing using conventional RT-PCR or real-time RT-PCR in symptomatic patients with SFTS may result in missed diagnoses, and compared with these methods, nested RT-PCR may increase the window for obtaining positive SFTSV PCR results. Meanwhile, the indirect immunofluorescence assay showed seroconversion to SFTSV antibodies in all four patients. Nested RT-PCR for SFTSV M and S segments could help diagnose SFTS in patients testing negative by conventional RT-PCR.


2006 ◽  
Vol 175 (4S) ◽  
pp. 485-486
Author(s):  
Sabarinath B. Nair ◽  
Christodoulos Pipinikas ◽  
Roger Kirby ◽  
Nick Carter ◽  
Christiane Fenske

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Yang Zhang ◽  
Chunyang Dai ◽  
Huiyan Wang ◽  
Yong Gao ◽  
Tuantuan Li ◽  
...  

Abstract Background Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is posing a serious threat to global public health. Reverse transcriptase real-time quantitative polymerase chain reaction (qRT-PCR) is widely used as the gold standard for clinical detection of SARS-CoV-2. Due to technical limitations, the reported positive rates of qRT-PCR assay of throat swab samples vary from 30 to 60%. Therefore, the evaluation of alternative strategies to overcome the limitations of qRT-PCR is required. A previous study reported that one-step nested (OSN)-qRT-PCR revealed better suitability for detecting SARS-CoV-2. However, information on the analytical performance of OSN-qRT-PCR is insufficient. Method In this study, we aimed to analyze OSN-qRT-PCR by comparing it with droplet digital PCR (ddPCR) and qRT-PCR by using a dilution series of SARS-CoV-2 pseudoviral RNA and a quality assessment panel. The clinical performance of OSN-qRT-PCR was also validated and compared with ddPCR and qRT-PCR using specimens from COVID-19 patients. Result The limit of detection (copies/ml) of qRT-PCR, ddPCR, and OSN-qRT-PCR were 520.1 (95% CI: 363.23–1145.69) for ORF1ab and 528.1 (95% CI: 347.7–1248.7) for N, 401.8 (95% CI: 284.8–938.3) for ORF1ab and 336.8 (95% CI: 244.6–792.5) for N, and 194.74 (95% CI: 139.7–430.9) for ORF1ab and 189.1 (95% CI: 130.9–433.9) for N, respectively. Of the 34 clinical samples from COVID-19 patients, the positive rates of OSN-qRT-PCR, ddPCR, and qRT-PCR were 82.35% (28/34), 67.65% (23/34), and 58.82% (20/34), respectively. Conclusion In conclusion, the highly sensitive and specific OSN-qRT-PCR assay is superior to ddPCR and qRT-PCR assays, showing great potential as a technique for detection of SARS-CoV-2 in patients with low viral loads.


2015 ◽  
Vol 65 ◽  
pp. 11-19 ◽  
Author(s):  
Je-Hyoung Kim ◽  
Chom-Kyu Chong ◽  
Mangalam Sinniah ◽  
Jeyaindran Sinnadurai ◽  
Hyun-Ok Song ◽  
...  

Author(s):  
Rajeev Kumar Jain ◽  
Nagaraj Perumal ◽  
Rakesh Shrivastava ◽  
Kamlesh Kumar Ahirwar ◽  
Jaya Lalwani ◽  
...  

Introduction: The whole world is facing an ongoing global health emergency of COVID-19 disease caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Real-Time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) is a gold standard in the detection of SARS-CoV-2 infection. Presently, many single tube multiple gene target RT-PCR kits have been developed and are commercially available for Coronavirus Disease 2019 (COVID-19) diagnosis. Aim: To evaluate the performance of seven COVID-19 RT-PCR kits (DiagSure, Meril, VIRALDTECT II, TruPCR, Q-line, Allplex and TaqPath) which are commercially available for COVID-19 RT-PCR diagnosis. Materials and Methods: This observational study was conductedat the State Virology Laboratory (SVL), Gandhi Medical College, Bhopal, Madhya Pradesh, India. Seven commercially available kits have been evaluated on the basis of: (i) number of SARS-CoV-2 specific gene target; (ii) human housekeeping genes as internal control; (iii) RT-PCR run time; and (iv) kit performances to correctly detect SARS-CoV-2 positive and negative RNA samples. A total of 50 RNA samples (left over RNA) were included, master mix preparation, template addition and RT-PCR test has been performed according to kits literature. At the end of PCR run, mean and standard deviation of obtained cut-off of all kits were calculated using Microsoft Excel. Results: All seven RT-PCR kits performed satisfactory regarding the reproducibility and they could correctly identify 30 positive and 20 negative RNA samples. RNA samples (group C) having low viral loads with a high Cycle threshold (Ct) value (>30) were also detected by all these seven kits. Obtained Ct values of each group was in parallel range in comparison with the initial testing Ct values. Kits were found to be superior which contains primers and probes for three SARS-CoV-2 specific gene targets, have human housekeeping gene as internal control and taking less time to complete RT-PCR. Conclusion: All seven COVID-19 RT-PCR kits included in this study demonstrated satisfactory performance and can be used for the routine molecular diagnosis of COVID-19 disease.


2018 ◽  
Vol 6 (1) ◽  
pp. 2 ◽  
Author(s):  
David De la Torre ◽  
Claudete Astolfi-Ferreira ◽  
Ruy Chacon ◽  
Antonio Piantino Ferreira

Avian rotavirus A (ARtV-A) is a virus that affects young birds, causing acute diarrhea and economic losses in the poultry industry worldwide. The techniques used for the diagnosis of ARtV-A include electron microscopy, isolation in cell culture, and serology, as well as molecular techniques, such as the reverse transcription-polymerase chain reaction (RT-PCR). The objective of this work was to standardize a real-time RT-polymerase chain reaction (RT-qPCR) using SYBR Green chemistry for the rapid detection and quantification of ARtV-A from bird tissues and materials fixed on FTA cards on the basis of the nucleotide sequence of segment 6 (S6), which codes for the structural VP6 protein of ARtV-A. The results show the efficient amplification of the proposed target, with a limit of detection (LoD) of one copy gene (CG) per microliter of cDNA and a limit of quantification (LoQ) of 10 CGs per microliter. The efficiency of the primers was determined to be 95.66% using a standard curve, with an R2 value of 0.999 and a slope of −3.43. The specificity was determined using samples coinfected with ARtV-A, the chicken parvovirus, the chicken astrovirus, and the avian nephritis virus as positive controls and commercially available vaccines of the infectious bronchitis virus, infectious bursa disease virus, avian reovirus and healthy organs as negative controls. This technique, which lacks nonspecific PCR products and dimers, demonstrated greater sensitivity and specificity than conventional RT-PCR, and it reduced the analysis time by more than 50%.


Parasitology ◽  
2020 ◽  
Vol 147 (10) ◽  
pp. 1140-1148
Author(s):  
Fernanda do Carmo Magalhães ◽  
Samira Diniz Resende ◽  
Carolina Senra ◽  
Carlos Graeff-Teixeira ◽  
Martin Johannes Enk ◽  
...  

AbstractDue to the efforts to control schistosomiasis transmission in tropical countries, a large proportion of individuals from endemic areas present low parasite loads, which hinders diagnosis of intestinal schistosomiasis by the Kato-Katz (KK) method. Therefore, the development of more sensitive diagnostic methods is essential for efficient control measures. The aim was to evaluate the accuracy of a real-time polymerase chain reaction (RT-PCR) to detect Schistosoma mansoni DNA in fecal samples of individuals with low parasite loads. A cross-sectional population-based study was conducted in a rural community (n = 257) in Brazil. POC-CCA® was performed in urine and feces were used for RT-PCR. In addition, fecal exams were completed by 18 KK slides, saline gradient and Helmintex techniques. The combined results of the three parasitological tests detected schistosome eggs in 118 participants (45.9%) and composed the consolidated reference standard (CRS). By RT-PCR, 117 out of 215 tested samples were positive, showing 91.4% sensitivity, 80.2% specificity and good concordance with the CRS (kappa = 0.71). RT-PCR identified 86.9% of the individuals eliminating less than 12 eggs/g of feces, demonstrating much better performance than POC-CCA® (50.8%). Our results showed that RT-PCR is a valuable alternative for the diagnosis of intestinal schistosomiasis in individuals with very low parasite loads.


2009 ◽  
Vol 21 (5) ◽  
pp. 679-683 ◽  
Author(s):  
Pamela J. Ferro ◽  
Jason Osterstock ◽  
Bo Norby ◽  
Geoffrey T. Fosgate ◽  
Blanca Lupiani

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.


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