scholarly journals Development of multiplex real-time RT-PCR assay for the detection of SARS-CoV-2

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250942
Author(s):  
Huseyin Tombuloglu ◽  
Hussein Sabit ◽  
Ebtesam Al-Suhaimi ◽  
Reem Al Jindan ◽  
Khaled R. Alkharsah
Keyword(s):  
Real Time ◽  
Single Gene ◽  
False Negative ◽  
Diagnostic System ◽  
Virus Detection ◽  
Current Method ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Positive Results ◽  
Good Agreement

The outbreak of the new human coronavirus SARS-CoV-2 (also known as 2019-nCoV) continues to increase globally. The real-time reverse transcription polymerase chain reaction (rRT-PCR) is the most used technique in virus detection. However, possible false-negative and false-positive results produce misleading consequences, making it necessary to improve existing methods. Here, we developed a multiplex rRT-PCR diagnostic method, which targets two viral genes (RdRP and E) and one human gene (RP) simultaneously. The reaction was tested by using pseudoviral RNA and human target mRNA sequences as a template. Also, the protocol was validated by using 14 clinical SARS-CoV-2 positive samples. The results are in good agreement with the CDC authorized Cepheid`s Xpert® Xpress SARS-CoV-2 diagnostic system (100%). Unlike single gene targeting strategies, the current method provides the amplification of two viral regions in the same PCR reaction. Therefore, an accurate SARS-CoV-2 diagnostic assay was provided, which allows testing of 91 samples in 96-well plates in per run. Thanks to this strategy, fast, reliable, and easy-to-use rRT-PCR method is obtained to diagnose SARS-CoV-2.

Prevalence of SHV-extended spectrum β-lactamase producing carbapenem –resistantKlebsiellapneumoniae among patients with lower respiratory tractinfections in Babylon Province-Iraq.

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Fatima Moeen Abbas
Keyword(s):  
Resistance Rate ◽  
Combination Method ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Carbapenem Resistant ◽  
Extended Spectrum ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Tract Infections ◽  
Positive Results

This study was carried out to screen the prevalence of Klebsiella pneumoniae isolated from patients with lower respiratory tract infections in Babylon province.From December,2015 to the end of March,2016,a total of 100 sputum samples were collected from patients visited or hospitalized Merjan Teaching Hospital and Al- Hashimya General Hospital. Fifteenth (65%) isolates were identified as Klebsiellapneumoniae. All bacterial isolates were evaluated for extended spectrum β-lactamase (ESBL) production phenotypically using disk combination method. Eleven (73.3%) isolates were detected as ESBL-producers. Kirby-Bauer disk diffusion method was employed to determine resistance profile of ESBLs-positive isolates. Higher rates of resistance were observed for ampicillin and piperacillin antibiotics with (81.8%) and (72.7%) resistance rate, respectively, while the lowest rate was noticed for imipenem antibiotic (14.28%). Carbapenem-resistant isolates were investigated for blaSHV gene by Polymerase Chain Reaction (PCR) method, 2 (100%) isolates gave positive results.

Detection of Streptococcus pneumoniae in Sputum Samples by Real- Time PCR.

2020 ◽  
Vol 18 ◽  
Author(s):  
Pegah Shakib ◽  
Mohammad Reza Zolfaghari
Keyword(s):  
Streptococcus Pneumoniae ◽  
Real Time ◽  
Real Time Pcr ◽  
False Negative ◽  
Cross Sectional Study ◽  
Laboratory Culture ◽  
Cross Sectional ◽  
Negative Results ◽  
False Negative Results ◽  
Pcr Method

Background: Conventional laboratory culture-based methods for diagnosis of Streptococcus pneumoniae are time-consuming and yield false negative results. Molecular methods including real-time (RT)-PCR rapid methods and conventional PCR due to higher sensitivity and accuracy have been replaced instead traditional culture assay. The aim of the current study was to evaluate lytA gene for detection of Streptococcus pneumoniae in the cerebrospinal fluid of human patients with meningitis using real-time PCR assay. Material and Methods: In this cross-sectional study, a total of 30 clinical specimens were collected from patients in a period from September to December 2018. In order to evaluate the presence of lytA gene, conventional and real-time PCR methods were used without culture. Results: From 30 sputum samples five (16.66%) isolates were identified as S. pneumoniae by lytA PCR and sequencing. Discussion: In this research, an accurate and rapid real-time PCR method was used, which is based on lytA gene for diagnosis of bacteria so that it can be diagnosed. Based on the sequencing results, the sensitivity for detection of lytA gene was 100% (5/5).

Identification of Bacteroides forsythus in Subgingival Dental Plaque with the Aid of a Rapid PCR Method

1997 ◽  
Vol 76 (7) ◽  
pp. 1376-1380 ◽  
Author(s):  
J.H. Meurman ◽  
J. Wahlfors ◽  
A. Korhonen ◽  
P. Alakuijala ◽  
P. Väisänen ◽  
...  
Keyword(s):  
Dental Plaque ◽  
Subgingival Plaque ◽  
Chain Reaction ◽  
Rapid Pcr ◽  
Microbiological Methods ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Pre Treatment ◽  
Culture Positive ◽  
Positive Results

Bacteroides forsythus has been shown to be prevalent among patients with periodontitis. Conventional microbiological methods used to identify this bacterium, however, are laborious and time-consuming and are therefore not well-suited for screening purposes. We have developed a polymerase chain-reaction (PCR) method which is rapid, specific, and simple to perform and does not require other sample pre-treatment except a brief centrifugation. This method was applied to the detection of B. forsythus in subgingival plaque of 58 periodontitis patients. When compared with the results of conventional culturing, the PCR method always confirmed the culture-positive results, while none of the PCR negative samples was shown to be culture-positive. The PCR method appeared to give more than double the number of samples positive for B. forsythus than culturing (89.7% vs. 37.9%). The analysis requires less than 4 hrs to perform, and is specific only to B. forsythus and sensitive enough to detect fewer than 5 bacteria.

Quantitative Real-Time Polymerase Chain Reaction Detection of BK Virus Using Labeled Primers

2010 ◽  
Vol 134 (3) ◽  
pp. 444-448 ◽  
Author(s):  
Zhengming Gu ◽  
Jianmin Pan ◽  
Matthew J. Bankowski ◽  
Randall T. Hayden
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Real Time Pcr ◽  
Quantitative Polymerase Chain Reaction ◽  
Bk Virus ◽  
Clinical Samples ◽  
Quantitative Detection ◽  
Chain Reaction ◽  
Pcr Method ◽  
Polymerase Chain

Abstract Context.—BK virus infections among immunocompromised patients are associated with disease of the kidney or urinary bladder. High viral loads, determined by quantitative polymerase chain reaction (PCR), have been correlated with clinical disease. Objective.—To develop and evaluate a novel method for real-time PCR detection and quantification of BK virus using labeled primers. Design.—Patient specimens (n = 54) included 17 plasma, 12 whole blood, and 25 urine samples. DNA was extracted using the MagNA Pure LC Total Nucleic Acid Isolation Kit (Roche Applied Science, Indianapolis, Indiana); sample eluate was PCR-amplified using the labeled primer PCR method. Results were compared with those of a user-developed quantitative real-time PCR method (fluorescence resonance energy transfer probe hybridization). Results.—Labeled primer PCR detected less than 10 copies per reaction and showed quantitative linearity from 101 to 107 copies per reaction. Analytical specificity of labeled primer PCR was 100%. With clinical samples, labeled primer PCR demonstrated a trend toward improved sensitivity compared with the reference method. Quantitative assay comparison showed an R2 value of 0.96 between the 2 assays. Conclusions.—Real-time PCR using labeled primers is highly sensitive and specific for the quantitative detection of BK virus from a variety of clinical specimens. These data demonstrate the applicability of labeled primer PCR for quantitative viral detection and offer a simplified method that removes the need for separate oligonucleotide probes.

Establishment and evaluation of real-time PCR for West Nile virus detection

2009 ◽  
Vol 6 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Shi Li-Jun ◽  
Lu Mao-Min ◽  
Li Gang ◽  
Li Cheng-Yao ◽  
Zhang Jin-Gang
Keyword(s):  
West Nile Virus ◽  
Real Time ◽  
Virus Detection ◽  
Rt Pcr ◽  
Pcr Assay ◽  
West Nile ◽  
Capsid Protein Gene ◽  
Specific Test ◽  
Intercalating Dye ◽  
Polymerase Chain

AbstractA rapid real-time polymerase chain reaction (RT-PCR) for detecting West Nile virus (WNV) was established. Primers were designed according to the sequence of the capsid protein gene of WNV by Primer Premier 5.0. In this way, an inexpensive assay using the intercalating dye SYBR Green I was developed and validated. The amplifying curve showed that this method could successfully amplify 102 copies/μl of the WNV gene, while reference to Japanese encephalitis virus (JEV) and blank control were all negative. Tenfold successive dilutions of positive WNV DNA were used to measure the sensitivity of RT-PCR. The assay system showed high reproducibility with coefficient of variation (CV) <2%. Thus the newly established RT-PCR assay was shown to be a rapid, sensitive and specific test for detecting WNV.

scholarly journals Comparison of Four Polymerase Chain Reaction Methods for the Rapid Detection of Human Fecal Pollution in Marine and Inland Waters

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Dave S. Bachoon ◽  
Cortney M. Miller ◽  
Christen P. Green ◽  
Ernesto Otero
Keyword(s):  
Puerto Rico ◽  
Environmental Samples ◽  
Fecal Pollution ◽  
Chain Reaction ◽  
Bifidobacterium Adolescentis ◽  
Fecal Samples ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Positive Results ◽  
Human Specific

We compared the effectiveness of three PCR protocols for the detection ofBifidobacterium adolescentisand one PCR protocol for detectingBacteroidalesas indicators of human fecal pollution in environmental samples. Quantitative PCR indicated that a higher concentration ofB. adolescentisDNA was recovered from sewage samples on the 0.2 μm filters compared to the 0.45 μm filters, and there was no evidence of qPCR inhibitors in the DNA extracts. With the Matsuki method (1999),B. adolescentiswas detected only in undiluted sewage samples. The King method (2007) performed well and detectedB. adolescentisin all of the sewage dilutions (from undiluted to10−4). In contrast, the Bonjoch approach (2004) was effective at detectingB. adolescentisat lower dilutions (10−3) of sewage samples and it gave false positive results with some (3/8) pig fecal samples. Human-specificBacteroidales(HuBacs) were detected in the lower diluents of sewage samples but was positive in pig (6/8) and cattle fecal samples. PCR detection ofB. adolescentisin marine samples from Puerto Rico and freshwater samples from Georgia indicated that the PCR method of King et al. (2007) and the modified Layton method for HuBac were in agreement in detecting human fecal pollution in most sites.

Quantitative assessment of hematopoietic chimerism after bone marrow transplantation by real-time quantitative polymerase chain reaction

Blood ◽  
2002 ◽  
Vol 99 (12) ◽  
pp. 4618-4625 ◽  
Author(s):  
Mehdi Alizadeh ◽  
Marc Bernard ◽  
Bruno Danic ◽  
Charly Dauriac ◽  
Brigitte Birebent ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Stem Cell ◽  
Real Time ◽  
Real Time Pcr ◽  
Quantitative Assessment ◽  
Quantitative Polymerase Chain Reaction ◽  
Chain Reaction ◽  
Hematopoietic Stem ◽  
Pcr Method ◽  
Polymerase Chain

We have developed a real-time quantitative polymerase chain reaction (PCR) assay using TaqMan technology (Applied Biosystems, Foster City, CA) for monitoring donor cell engraftment in allogenic hematopoietic stem cell transplant recipients. For this purpose, we selected 19 specific sequence polymorphisms belonging to 11 human biallelic loci located on 9 different chromosomes. Using a set of specially designed primers and fluorogenic probes, we evaluated the 19 markers' informativity on a panel of 126 DNA samples from 63 recipient/donor pairs. In more than 90% of these pairs, discrimination between recipient and donor genetic profile was possible. By using serial dilutions of mixed DNAs, we evaluated the linearity and sensitivity of the method. A linear correlation with rhigher than 0.98 and a sensitivity of 0.1% proved reproducible. Fluorescent-based PCR of short tandem repeats (STR-PCR) and real-time PCR chimerism assay were compared with a panel of artificial cell mixtures. The main advantage of the real-time PCR method over STR-PCR chimerism assays is the absence of PCR competition and plateau biases, and results evidenced greater sensitivity and linearity with the real-time PCR method. Furthermore, different samples can be tested in the same PCR run with a final result in fewer than 48 hours. Finally, we prospectively analyzed patients who received allografts and present 4 different clinical situations that illustrate the informativity level of our method. In conclusion, this new assay provides an accurate quantitative assessment of mixed chimerism that can be useful in guiding early implementation of additional treatments in hematopoietic stem cell transplantation.

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