scholarly journals Direct detection of Dengue viruses without extraction of RNA on the mobile real-time PCR device

2020 ◽  
Author(s):  
Masaaki Muraoka ◽  
Yukiko Tanoi ◽  
Tetsutaro Tada ◽  
Aya Tabata ◽  
Mikio Mizukoshi ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Direct Detection ◽  
Positive Control ◽  
Nucleic Acid Amplification ◽  
Severe Dengue ◽  
Mosquito Vectors ◽  
Rt Pcr ◽  
The Real ◽  
One Step

ABSTRACTDengue virus (DENV) is the cause of dengue / severe dengue and a virus of the Flaviviridae family, furthermore, dengue fever has rapidly spread in the world in recent decades. DENV is transmitted by female mosquitoes, mainly of the specie Aedes aegypti. The main method to control or prevent the transmission of DENV is to combat the mosquito vectors. Among these, one of important methods is to monitor the DENVs in the mosquito vectors.For the detection of DENV, nucleic acid amplification tests (NAAT) were recommended, of which criterion standard is real-time RT-PCR with highly sensitive and specific. However, it takes long time as to judge the result per a reaction, besides the necessity of the treatment of RNA in advance, example of extraction, concentration and purification.It was our object in this time to develop the method of real-time RT-PCR detecting DENVs in shorter time, moreover without especial treatment of RNA from the mosquito in advance. Besides, this work was performed with combing the mobile real-time PCR device with the one-step RT-PCR reagent.Firstly, we succeeded in shortening the time of real-time RT-PCR for the detection of DENV per one reaction, so that the judgement needed less than 20 minutes if genomic RNA treated in advance. Moreover, each value on the real-PCR device was quantitatively correlated with the positive control RNA from 1.0 × 10 ^ 3 copies to 1.0 × 10 ^ 0 copies per reaction (This correlation coefficient R2 > 0.95). Additionally, it made sure that this method could be applied to each DENV serotype.Secondly, we established the basis of procedure for the real-time RT-PCR without the treatment in advance so-called “direct”. As the result that the positive control RNA additive was utilized instead of the real DENV, spiked into the mosquito homogenized and sampled the supernatant without treatment, it was possible to detect on the real-time RT-PCR even if mosquitoes immediately after blood-feeding. For this reason, this method might be able to utilize in human sera, too.According to the results of this work, we could suggest the method is possible to detect DENV more quickly and more simply than heretofore. The Real-time “direct” RT-PCR, especially, could be performed with mobile real-time PCR PCR1100 device and one step RT-PCR reagent only. This method must help to detect some viruses other than DENV, too.

scholarly journals Quickly and simply detection for coronaviruses including SARS-CoV-2 on the mobile Real-Time PCR without treating RNA in advance

2020 ◽  
Author(s):  
Masaaki Muraoka ◽  
Yukiko Tanoi ◽  
Tetsutaro Tada ◽  
Mikio Mizukoshi ◽  
Osamu Kawaguchi
Keyword(s):  
Real Time ◽  
Correlation Coefficient ◽  
Real Time Pcr ◽  
Positive Control ◽  
List Type ◽  
Rt Pcr ◽  
Human Coronavirus ◽  
One Step ◽  
Short Time ◽  
Human Coronavirus 229E

ABSTRACTSARS-CoV-2 was reported to the WHO as an outbreak in Wuhan City, China on end of 2019, afterwards pandemic on the worldwide in 2020. The SARS-CoV-2 virus is less deadly, but far more transmissible. Therefore, it needs to detect and monitor quickly and simply on site to prevent SARS-CoV-2.If detecting coronaviruses including SARS-CoV-2, the real-time RT-PCR method is sensitive and specific for the unique target, however, it must take long time and labour that RNA is treated in advance, transcribed and amplified. Therefore, referenced previously report, in this study, we modified various methods to prove hypotheses the followed.Firstly, we hypothesized that real-time RT-PCR could be finished in very short time by the mobile real-time PCR device and one-step RT-PCR reagent. Secondly, we hypothesized that it was possible to perform RT-PCR utilizing the reagent as the above without RNA treatment in advance so called “direct”.Firstly, it was able to detect the positive control RNA of SARS-CoV-2 for less than 13.5 minutes by primer-probe referring to the CDC. Moreover, each detection value varied in accordance with each concentration (This correlation coefficient R2 > 0.95). Secondary, it was possible to detect human coronavirus 229E with direct RT-PCR. Furthermore, each detection value varied in accordance with each titer (TCID50 / mL) of human coronavirus 229E (This correlation coefficient R2 > 0.95).Considering the above, causing by utilizing the mobile real-time PCR device and the one-step real-time PCR reagent simultaneously following as: 1) It was possible to detect SARS-CoV-2 in very short time as compared to conventional method; 2) It was possible to detect human coronavirus quickly and simply with “direct”. For these reasons, we hypothesized that it is possible to detect SARS-CoV-2 quickly and simply by utilizing methods the above without treating RNA in advance. This hypothesis is our next try.STRENGTHS AND LIMITATIONS OF THIS STUDY*This study developed it possible to detect the positive control RNA of SARS-CoV-2 more quickly than previously, however couldn’t try to detect the genetic RNA.*This study proved clearly that the human coronavirus instead of SARS-CoV-2 could be detected simply without treating RNA in advance by the same method above.*This study couldn’t try to utilize the human specimens because of our institution limited.*This study could utilize the device and the reagents commercial and not especial.

scholarly journals Direct detection of microorganisms responsible for the sexually transmitted infection on the mobile real-time PCR device without treating in advance

2021 ◽  
Author(s):  
Masaaki Muraoka ◽  
Kazunori Sohma ◽  
Osamu Kawaguchi ◽  
Mikio Mizukoshi
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Limit Of Detection ◽  
Direct Detection ◽  
Treponema Pallidum ◽  
Nucleic Acid Amplification ◽  
Direct Pcr ◽  
Transmitted Infection ◽  
Sexually Transmitted ◽  
Ct Value

ABSTRACTAs WHO reported, four curable STIs-chlamydia, gonorrhoea, syphilis and trichomoniasis occur more than 1 million per each day globally almond 2016. For this reason, it is important to control these STIs, one of which is “to detect”. The general methods in order to detect STIs are nucleic acid amplification tests (NAATs). One of the reasons why NAATs are utilized in many tests is that it is possibly to be more sensitive than other test. However, there needs to treat extraction of nucleic acids in advance and amplify specific regions by NAATs, and hence it must take much labour and much time. In this work, for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Treponema pallidum (TP) which is each etiological agent of chlamydia, gonorrhoea and syphilis, we evaluate and propose “quicker and simpler” NAATs. Specifically, utilizing mobile real-time PCR device “PCR1100” and PCR reagent kit “KAPA3G Plant PCR Kit”, it was considered whether real-time direct PCR could be performed or not without treating DNA extraction in advance so-called “direct”.As a result, firstly, we established that real-time direct PCR could be performed in all of CT, NG, and TP, and moreover, each Ct value correlated with the concentration of each organism similarly to detection of genome DNA (each correlation coefficient R2 > 0.95). Moreover, each assay demonstrated a limit of detection (LOD) of the follows; CT was 10^0.86 = 7.24 IFU/reaction, NG was 10^-0.19 = 0.65 CFU/reaction, and TP was 10^1.4 = 25.1 organisms/reaction. However, it appeared the sensitivity was a little low, especially for CT and TP.Secondly, we found that even as without treating sample in advance, the time of detection was required more less 15 minutes at any of case, which was very quick compared with other current methods for real-time PCR. Additionally, compared with other commercial devices, it was easier to operate the PCR1100 device, for example, start, analysis of Ct value.In conclusion, the present study has demonstrated that it is possible for real-time direct PCR to perform with combination of the PCR1100 device and the PCR reagent kit in 3 kinds of microorganisms-CT, NG and TP. Furthermore, we propose “quicker and simpler” methods for NAATs, which it would not take labour and time. Further studies are needed in order to contribute to control STIs.

Detection and Enumeration of Salmonella Enteritidis in Homemade Ice Cream Associated with an Outbreak: Comparison of Conventional and Real-Time PCR Methods

2006 ◽  
Vol 69 (3) ◽  
pp. 639-643 ◽  
Author(s):  
K. H. SEO ◽  
I. E. VALENTIN-BON ◽  
R. E. BRACKETT
Keyword(s):  
Real Time ◽  
Quantitative Pcr ◽  
Real Time Pcr ◽  
Salmonella Enteritidis ◽  
Direct Detection ◽  
Ice Cream ◽  
Plate Count ◽  
Pcr Assay ◽  
The Real ◽  
Real Time Quantitative Pcr

Salmonellosis caused by Salmonella Enteritidis (SE) is a significant cause of foodborne illnesses in the United States. Consumption of undercooked eggs and egg-containing products has been the primary risk factor for the disease. The importance of the bacterial enumeration technique has been enormously stressed because of the quantitative risk analysis of SE in shell eggs. Traditional enumeration methods mainly depend on slow and tedious most-probable-number (MPN) methods. Therefore, specific, sensitive, and rapid methods for SE quantitation are needed to collect sufficient data for risk assessment and food safety policy development. We previously developed a real-time quantitative PCR assay for the direct detection and enumeration of SE and, in this study, applied it to naturally contaminated ice cream samples with and without enrichment. The detection limit of the real-time PCR assay was determined with artificially inoculated ice cream. When applied to the direct detection and quantification of SE in ice cream, the real-time PCR assay was as sensitive as the conventional plate count method in frequency of detection. However, populations of SE derived from real-time quantitative PCR were approximately 1 log higher than provided by MPN and CFU values obtained by conventional culture methods. The detection and enumeration of SE in naturally contaminated ice cream can be completed in 3 h by this real-time PCR method, whereas the cultural enrichment method requires 5 to 7 days. A commercial immunoassay for the specific detection of SE was also included in the study. The real-time PCR assay proved to be a valuable tool that may be useful to the food industry in monitoring its processes to improve product quality and safety.

Paradigm for diagnosing mycobacterial disease: direct detection and differentiation of Mycobacterium tuberculosis complex and non-tuberculous mycobacteria in clinical specimens using multiplex real-time PCR

2018 ◽  
Vol 71 (9) ◽  
pp. 774-780 ◽  
Author(s):  
Jeong-Uk Kim ◽  
Dae-Shick Ryu ◽  
Choong-Hwan Cha ◽  
Seon-Hee Park
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Real Time ◽  
Real Time Pcr ◽  
Predictive Value ◽  
Direct Detection ◽  
Positive Culture ◽  
Nucleic Acid Amplification ◽  
Mycobacterial Disease ◽  
Pcr Assay ◽  
Clinical Specimens

AimsMycobacterium tuberculosis and non-tuberculous mycobacteria (NTM) are clinically different, and the rapid detection and differentiation of M. tuberculosis complex (MTBC) and NTM is crucial for patient management and infection control. Given the slow growth of most pathogenic mycobacteria, nucleic acid amplification assays are excellent tools for direct identification of mycobacteria in clinical specimens. Recently, a multiplex real-time PCR assay was developed that can directly detect 20 mycobacterial species in clinical specimens. Here, we evaluated the diagnostic performance of the assay for diagnosing mycobacterial disease under routine laboratory conditions.MethodsA total of 3334 specimens collected from 1437 patients suspected of tuberculosis infection were subjected to acid-fast bacilli staining, conventional culture and the multiplex real-time PCR assay. To evaluate the sensitivity and specificity of the assay, the overall diagnosis of tuberculosis was defined by positive culture plus medical history, and the 2007 American Thoracic Society and Infectious Disease Society of America diagnostic criteria for NTM disease were applied.ResultsThe sensitivity, specificity, positive predictive value and negative predictive value were 87.5%, 99.6%, 96.1% and 98.5%, respectively, for the detection of MTBC isolates and 53.3%, 99.9%, 95.2%, and 98.9%, respectively, for detecting NTM isolates.ConclusionsThus, the assay can correctly differentiate between MTBC and NTM isolates in clinical specimens and would be a useful tool for the rapid differentiation of tuberculosis and NTM disease, despite its limited sensitivity for the diagnosis of NTM disease.

scholarly journals Comparison of a one-step real-time RT-PCR and a nested real-time RT-PCR for a genogroup II norovirus reveals differences in sensitivity depending upon assay design and visualization

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0248581
Author(s):  
Clyde S. Manuel ◽  
Cassandra Suther ◽  
Matthew D. Moore ◽  
Lee-Ann Jaykus
Keyword(s):  
Detection Limit ◽  
Real Time ◽  
Real Time Pcr ◽  
Environmental Samples ◽  
Blot Hybridization ◽  
Molecular Techniques ◽  
Rt Pcr ◽  
Dot Blot ◽  
Dot Blot Hybridization ◽  
One Step

Human norovirus (NoV) is the leading cause of acute viral gastroenteritis and a major source of foodborne illness. Detection of NoV in food and environmental samples is typically performed using molecular techniques, including real-time reverse transcription polymerase chain reaction (RT-PCR) and less frequently, nested real-time PCR. In this study, we conducted a controlled comparison of two published NoV detection assays: a broadly reactive one-step real-time RT-PCR and a two-step nested real-time PCR assay. A 20% human fecal suspension containing a genogroup II human NoV was serially diluted, genome extracted, and subjected to amplification using the two assays compared via PCR Units. Additional amplicon confirmation was performed by dot blot hybridization using digoxigenin (DIG)-labeled oligonucleotide probes. Both assays displayed similar amplification standard curves/amplification efficiencies; however, the nested assay consistently detected one log10 lower virus. Dot blot hybridization improved the detection limit of the nested real-time PCR by one log10 NoV genome copies but impaired the detection limit of the one-step real-time RT-PCR by one log10 NoV genome copies. These results illustrate the complexities in designing and interpreting molecular techniques having a sufficient detection limit to detect low levels of viruses that might be anticipated in contaminated food and environmental samples.

scholarly journals Genetic Diversity of Porcine Reproductive and Respiratory Syndrome Virus and Evaluation of Three One-Step Real-Time RT-PCR Assays in Korea

2021 ◽  
Author(s):  
Go-Eun Shin ◽  
Ji-Young Park ◽  
Kyoung-Ki Lee ◽  
Mi-Kyeong Ko ◽  
Bok-Kyung Ku ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Real Time ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Nucleotide Sequence Analysis ◽  
Rt Pcr ◽  
The Real ◽  
One Step ◽  
Pcr Assays

Abstract Background Porcine reproductive and respiratory syndrome virus (PRRSV) has caused huge economic losses in the global swine industry. Frequent genetic variations in this virus cause difficulties in controlling and accurately diagnosing PRRSV. Methods In this study, we investigated the genetic characteristics of PRRSV-1 and PRRSV-2 circulating in Korea from January 2018 to September 2021 and evaluated three one-step real-time reverse transcription polymerase chain reaction (RT-PCR) assays. Results A total of 129 lung samples were collected, consisting of 47 samples for PRRSV-1, 62 samples for PRRSV-2, and 20 PRRSV-negative samples. Nucleotide sequence analysis of open reading frames (ORFs) 5, ORF6, and ORF7 genes from PRRSV samples showed that PRRSV-1 belonged to subgroup A (43/47, 91.49%) and subgroup C (4/47, 8.51%), whereas PRRSV-2 was classified as lineage 1 (25/62, 40.32%), Korean lineage (Kor) C (13/62, 20.97%), Kor B (10/62, 16.13%), lineage 5 (9/62, 14.52%), and Kor A (5/62, 8.06%). Amino acid sequence analysis showed that the neutralizing epitope and T cell epitope of PRRSV-1, and the decoy epitope region and hypervariable regions of PRRSV-2 had evolved under positive selection pressure. In particular, the key amino acid substitutions were found at positions 102 and 104 of glycoprotein 5 (GP5) in some PRRSV-2, and at positions 10 and 70 of membrane protein (M) in most PRRSV-2. In addition, one-step real-time RT-PCR assays, comprising two commercial tests and one test recommended by the World Organization for Animal Health (OIE), were evaluated. Conclusion The results revealed that two of the real-time RT-PCR assays had high sensitivities and specificities, whereas the real-time RT-PCR assay of the OIE had low sensitivity due to mismatches between nucleotides of Korean PRRSVs and forward primers. In this study, we genetically characterized recent PRRSV occurrences and evaluated three one-step real-time RT-PCR assays used in Korea.

scholarly journals Comparison of SARS-CoV2 N gene real-time RT-PCR targets and commercially available mastermixes

2020 ◽  
Author(s):  
Julianne R Brown ◽  
Denise O’Sullivan ◽  
Rui PA Pereira ◽  
Alexandra S Whale ◽  
Eloise Busby ◽  
...  
Keyword(s):  
Real Time ◽  
Lower Limit ◽  
Real Time Pcr ◽  
Limit Of Detection ◽  
N Gene ◽  
Rt Pcr ◽  
One Step ◽  
Improved Performance ◽  
Rna Transcript ◽  
Nose And Throat

ABSTRACTWe aim to test four one-step RT real-time mastermix options for use in SARS-CoV2 real-time PCR, with three primer/probe assays targeting the N gene. The lower limit of detection is determined using a SARS CoV2 N gene RNA transcript dilution series (to 1 copy/µl) and verified using 74 nose and throat swabs.The N2 assay demonstrates the most sensitive detection of SARS-Cov-2 RNA. Three of the four mastermixes performed well, with the Takara One Step PrimeScript™ III RT-PCR Kit mastermix demonstrating improved performance at the lower limit of detection.

scholarly journals Direct Quantitative Detection and Identification of Lactococcal Bacteriophages from Milk and Whey by Real-Time PCR: Application for the Detection of Lactococcal Bacteriophages in Goat's Raw Milk Whey in France

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Mai Huong Ly-Chatain ◽  
Loïc Durand ◽  
Véronique Rigobello ◽  
Annabelle Vera ◽  
Yann Demarigny
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Direct Detection ◽  
Raw Milk ◽  
Quantitative Detection ◽  
Amplification Efficiency ◽  
The Real ◽  
Milk Whey ◽  
Detection And Identification ◽  
Milk Fermentation

The presence ofLactococcusbacteriophages in milk can partly or completely inhibit milk fermentation. To prevent the problems associated with the bacteriophages, the real-time PCR was developed in this study for direct detection from whey and milk of three main groups ofLactococcusbacteriophages, c2, 936, and P335. The optimization of DNA extraction protocol from complex matrices such as whey and milk was optimized allowed the amplification of PCR without any matrix and nontarget contaminant interference. The real-time PCR program was specific and with the detection limit of 102PFU/mL. The curve slopes were −3.49, −3.69, and −3.45 with the amplification efficiency estimated at 94%, 94%, and 98% and the correlation coefficient () of 0.999, 0.999, and 0.998 for c2, 936 and P335 group, respectively. This method was then used to detect the bacteriophages in whey and goat's raw milk coming from three farms located in the Rhône-Alpes region (France).

Multiplex real-time PCR assays for the prediction of cephalosporin, ciprofloxacin and azithromycin antimicrobial susceptibility of positive Neisseria gonorrhoeae nucleic acid amplification test samples

2020 ◽  
Vol 75 (12) ◽  
pp. 3485-3490 ◽  
Author(s):  
S W Peterson ◽  
I Martin ◽  
W Demczuk ◽  
N Barairo ◽  
P Naidu ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Neisseria Gonorrhoeae ◽  
Real Time ◽  
Real Time Pcr ◽  
Nucleic Acid Amplification ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Snp Analysis ◽  
Rt Pcr ◽  
Pcr Assays

Abstract Background The incidence of antimicrobial-resistant Neisseria gonorrhoeae (GC) is rising in Canada; however, antimicrobial resistance (AMR) surveillance data are unavailable for infections diagnosed directly from clinical specimens by nucleic acid amplification tests (NAATs), representing over 80% of diagnoses. We developed a set of 10 improved molecular assays for surveillance of GC-AMR and prediction of susceptibilities in NAAT specimens. Methods Multiplex real-time PCR (RT–PCR) assays were developed to detect SNPs associated with cephalosporin (ponA, porB, mtrR −35delA, penA A311V, penA A501, N513Y, G545S), ciprofloxacin (gyrA S91, parC D86/S87/S88) and azithromycin [23S (A2059G, C2611T), mtrR meningitidis-like promoter] resistance. The assays were validated on 127 gonococcal isolates, 51 non-gonococcal isolates and 50 NAATs with matched culture isolates. SNPs determined from the assay were compared with SNPs determined from in silico analysis of WGS data. MICs were determined for culture isolates using the agar dilution method. Results SNP analysis of the 50 NAAT specimens had 96% agreement with the matched culture RT–PCR analysis. When compared with MICs, presence of penA A311V or penA A501 and two or more other SNPs correlated with decreased susceptibility and presence of three or more other SNPs correlated with intermediate susceptibility to cephalosporins; presence of any associated SNP correlated with ciprofloxacin or azithromycin resistance. NAAT-AMR predictions correlated with matched-culture cephalosporin, ciprofloxacin and azithromycin MICs at 94%, 100% and 98%, respectively. Conclusions We expanded molecular tests for N. gonorrhoeae AMR prediction by adding new loci and multiplexing reactions to improve surveillance where culture isolates are unavailable.

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