Universal extraction method for gastrointestinal pathogens

2013 ◽  
Vol 62 (10) ◽  
pp. 1535-1539 ◽  
Author(s):  
Fenella D. Halstead ◽  
Adele V. Lee ◽  
Xose Couto-Parada ◽  
Spencer D. Polley ◽  
Clare Ling ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Extraction Method ◽  
Treatment Method ◽  
Universal Method ◽  
Rapid Diagnostics ◽  
Time Saving ◽  
Bead Beating ◽  
Gastrointestinal Pathogens ◽  
Disease Study

A universal stool extraction method for recovery of nucleic acids (NAs) from gastrointestinal pathogens was developed to support rapid diagnostics for the London 2012 Olympics. The method involved mechanical disruption (bead beating) of the stools, followed by automated extraction and detection using real-time PCR. This method had been used extensively in the Second Infectious Intestinal Disease Study (IID2) for the isolation of NA from bacteria and parasites (and was effective for the robust recovery of Cryptosporidium spp.) but had not been used for enteric viruses. To ensure this method was universally suitable, panels of samples known to contain target bacteria, viruses or parasites were processed in triplicate using the pre-treatment method routinely used for each target and the new extraction method (bead beating). The extracts were tested using real-time PCR and the cycle threshold values were compared. The results from this study showed that bead beating improved yields for the bacterial and parasitic targets and was suitable for the viral targets. The implementation of this universal method should confer cost- and time-saving benefits and streamline the processes required for the characterization of an array of pathogens from faecal samples.

Giardia duodenalis typing from stools: a comparison of three approaches to extracting DNA, and validation of a probe-based real-time PCR typing assay

2014 ◽  
Vol 63 (1) ◽  
pp. 38-44 ◽  
Author(s):  
K. Elwin ◽  
H. V. Fairclough ◽  
S. J. Hadfield ◽  
R. M. Chalmers
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Giardia Duodenalis ◽  
Treatment Method ◽  
Gene Probe ◽  
Freeze Thaw ◽  
Bead Beating ◽  
Dna Yield ◽  
Technical Requirements ◽  
Spin Column

A weighted, multi-attribute approach was used to compare three methods for direct extraction of Giardia duodenalis DNA from 15 microscopy-positive stools: (1) a QIAamp spin-column method for stools including a 10 min incubation at 95 °C, (2) method 1 preceded by five freeze–thaw cycles and (3) bead beating with guanidine thiocyanate using a FastPrep-28 machine followed by liquid-phase silica purification of DNA. The attributes compared included DNA yield measured using a new triose phosphate isomerase (tpi) gene probe-based real-time PCR, also described here. All three methods shared 100 % PCR positivity, while the bead-beating method provided the highest G. duodenalis DNA yield (P<0.01). However, when other weighted attributes, including biocontainment, resources and technical requirements, were also considered, spin-column extraction with prior freeze–thaw treatment (method 2) was deemed the most desirable and was selected for use. The tpi real-time PCR typing assay was designed to discriminate between the main human infectious assemblages of G. duodenalis (A and B) and was evaluated initially using standard isolates. Validation using microscopy-positive stools from 78 clinical giardiasis cases revealed 100 % typability; 20 (26 %) samples contained assemblage A, 56 (72 %) assemblage B and two (3 %) assemblages A and B. While the epidemiological significance of assemblage distribution will be revealed as more isolates are typed and analysed with patient demographic and exposure data, the utility of this assay and its ready application in our laboratory workflow and result turnaround margins is already evident.

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

Pathogens ◽  
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.

Direct detection ofCampylobacter jejuniin human stool samples by real-time PCR

2008 ◽  
Vol 54 (9) ◽  
pp. 742-747 ◽  
Author(s):  
Shiyong Lin ◽  
Xinying Wang ◽  
Haoxuan Zheng ◽  
Zhengguo Mao ◽  
Yong Sun ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Direct Detection ◽  
Culture Method ◽  
Turnaround Time ◽  
Culture Methods ◽  
Time Saving ◽  
Whole Process ◽  
Pure Cultures ◽  
Stool Samples

Our purpose was to establish a quick and accurate real-time PCR (rtPCR) method to detect Campylobacter jejuni directly from human diarrheal stool as an alternative to traditional culture methods. To determine the consistency of rtPCR and culture method, 256 clinical diarrheal stool samples and 50 normal stool samples from healthy individuals were examined, and the whole process was double-blinded. Our data showed that the sensitivity of rtPCR in pure cultures and stool was 102CFU·mL–1and 103CFU·g–1, respectively. Of the 256 diarrheal samples, 10 specimens were successfully detected by both methods, whereas two specimens were PCR positive but culture negative. No positive results were found by these two methods in 50 normal specimens. Our data suggested that rtPCR was convenient in operation and time-saving (turnaround time 3.5–4 h), so it could be used for clinical diagnostic and epidemiological purposes.

scholarly journals A rapid RNA extraction method from oil palm tissues suitable for reverse transcription quantitative real-time PCR (RT-qPCR)

3 Biotech ◽  
2020 ◽  
Vol 10 (12) ◽  
Author(s):  
Siti Suriawati Badai ◽  
Omar Abd Rasid ◽  
Ghulam Kadir Ahmad Parveez ◽  
Mat Yunus Abdul Masani
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Oil Palm ◽  
Real Time Pcr ◽  
Extraction Method ◽  
Rna Extraction ◽  
Quantitative Real Time Pcr

Evaluation of a co-extraction method for real-time PCR-based body fluid identification and DNA typing

2014 ◽  
Vol 16 (1) ◽  
pp. 56-59 ◽  
Author(s):  
Ken Watanabe ◽  
Yasuki Iwashima ◽  
Tomoko Akutsu ◽  
Kazumasa Sekiguchi ◽  
Koichi Sakurada
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Extraction Method ◽  
Body Fluid ◽  
Dna Typing ◽  
Body Fluid Identification ◽  
Fluid Identification

scholarly journals Comparison of DNA extraction methods for Aspergillus fumigatus using real-time PCR

2006 ◽  
Vol 55 (9) ◽  
pp. 1187-1191 ◽  
Author(s):  
Lisa J. Griffiths ◽  
Martin Anyim ◽  
Sarah R. Doffman ◽  
Mark Wilks ◽  
Michael R. Millar ◽  
...  
Keyword(s):  
Real Time ◽  
Dna Extraction ◽  
Real Time Pcr ◽  
Diagnostic Technique ◽  
Extraction Methods ◽  
Simple Method ◽  
Bead Beating ◽  
Fungal Dna ◽  
Dna Extraction Methods ◽  
High Level

Newer methods such as PCR are being investigated in order to improve the diagnosis of invasive aspergillosis. One of the major obstacles to using PCR to diagnose aspergillosis is a reliable, simple method for extraction of the fungal DNA. The presence of a complex, sturdy cell wall that is resistant to lysis impairs extraction of the DNA by conventional methods employed for bacteria. Numerous fungal DNA extraction protocols have been described in the literature. However, these methods are time-consuming, require a high level of skill and may not be suitable for use as a routine diagnostic technique. Here, a number of extraction methods were compared: a freeze–thaw method, a freeze–boil method, enzyme extraction and a bead-beating method using Mini-BeadBeater-8. The quality and quantity of the DNA extracted was compared using real-time PCR. It was found that the use of a bead-beating method followed by extraction with AL buffer (Qiagen) was the most successful extraction technique, giving the greatest yield of DNA, and was also the least time-consuming method assessed.

scholarly journals Comparison of real-time PCR and the Kato-Katz method for the diagnosis of soil-transmitted helminthiasis and assessment of cure in a randomized controlled trial

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Beatrice Barda ◽  
Christian Schindler ◽  
Rahel Wampfler ◽  
Shaali Ame ◽  
Said M. Ali ◽  
...  
Keyword(s):  
Real Time ◽  
Dna Extraction ◽  
Real Time Pcr ◽  
Controlled Trial ◽  
Bead Beating ◽  
Novel Treatments ◽  
Two Samples ◽  
Stool Samples ◽  
Pcr Method

Abstract Background Diagnosis of soil-transmitted helminths (STHs) in developing countries is commonly based on microscopic detection of eggs in stool samples, using the Kato-Katz (KK) method, which has a poor sensitivity for detecting light intensity infections. We compared the performance of the KK method and real-time PCR in the framework of a randomized trial, which evaluated four novel treatments against Trichuris trichiura and concomitant STH infections. Results Two stool samples obtained from 320 participants were examined at baseline and follow-up with quadruplicate KK and PCR analyses of one of the two samples using “bead-beating” for DNA extraction. At follow-up, 80 samples were negative according to both PCR and KK and 173 were positive with both methods for any of the STHs. Relative to PCR, the calculated sensitivity of KK at follow-up was 83.6%, 43.0% and 53.8% for T. trichiura, for hookworm and for Ascaris lumbricoides, respectively. The sensitivity of PCR compared with KK at this time point was 89.1% for T. trichiura, 72.7% for hookworm and 87.5% for A. lumbricoides. Cure rates (CRs) for T. trichiura and A. lumbricoides were slightly lower with the PCR method. For hookworm CRs with KK were mostly significantly lower, namely 36.7%, 91.1%, 72.2% and 77.8% for moxidectin, moxidectin in combination with tribendimidine, moxidectin in combination with albendazole and albendazole in combination with oxantel pamoate, respectively, whereas with PCR the CRs were 8.3%, 82.6%, 37.1% and 57.1%, respectively. Conclusions In conclusion, a single real-time PCR is as sensitive as quadruplicate KK for T. trichiura and A. lumbricoides detection but more sensitive for hookworm, which has an influence on the estimated treatment efficacy. PCR method with DNA extraction using the “bead-beating protocol” should be further promoted in endemic areas and laboratories that can afford the needed equipment. The study is registered at ISRCTN (no. 20398469).

Influence of Primer Sequences and DNA Extraction Method on Detection of Non-O157 Shiga Toxin–Producing Escherichia coli in Ground Beef by Real-Time PCR Targeting the eae, stx, and Serogroup-Specific Genes†

2012 ◽  
Vol 75 (11) ◽  
pp. 1939-1950 ◽  
Author(s):  
JAMIE L. WASILENKO ◽  
PINA M. FRATAMICO ◽  
NEELAM NARANG ◽  
GLENN E. TILLMAN ◽  
SCOTT LADELY ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Dna Extraction ◽  
Shiga Toxin ◽  
Real Time Pcr ◽  
Extraction Method ◽  
Ground Beef ◽  
Dna Extraction Method ◽  
Big Six ◽  
Pcr Targeting

Non-O157 Shiga toxin–producing Escherichia coli (STEC) infections, particularly those caused by the “big six” or “top six” non-O157 serogroups (O26, O45, O103, O111, O121, and O145) can result in severe illness and complications. Because of their significant public health impact and the notable prevalence of STEC in cattle, methods for detection of the big six non-O157 STEC in ground beef have been established. Currently, the U.S. Department of Agriculture, Food Safety and Inspection Service detection methods for screening beef samples for non-O157 STEC target the stx1, stx2, and eae virulence genes, with the 16S rRNA gene as an internal control, in a real-time PCR multiplex assay. Further, the serogroup is determined by PCR targeting genes in the E. coli O-antigen gene clusters of the big six non-O157 serogroups. The method that we previously reported was improved so that additional stx variants, stx1d, stx2e, and stx2g, are detected. Additionally, alignments of the primers targeting the eae gene were used to improve the detection assay so that eae subtypes that could potentially be of clinical significance would also be detected. Therefore, evaluation of alternative real-time PCR assay primers and probes for the stx and eae reactions was carried out in order to increase the stx and eae subtypes detected. Furthermore, a Tris-EDTA DNA extraction method was compared with a previously used procedure that was based on a commercially available reagent. The Tris-EDTA DNA extraction method significantly decreased the cycle threshold values for the stx assay (P &lt; 0.0001) and eae assay (P &lt; 0.0001), thereby increasing the ability to detect the targets. The use of different stx primers and probes increased the subtypes detected to include stx1d, stx2e, and stx2g, and sequence data showed that modification of the eae primer should allow the known eae subtypes to be detected.

scholarly journals Development of a Broad-Range 23S rDNA Real-Time PCR Assay for the Detection and Quantification of Pathogenic Bacteria in Human Whole Blood and Plasma Specimens

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Paolo Gaibani ◽  
Mara Mariconti ◽  
Gloria Bua ◽  
Sonia Bonora ◽  
Davide Sassera ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Whole Blood ◽  
Extraction Method ◽  
Sample Type ◽  
Blood Samples ◽  
Human Whole Blood ◽  
Rdna Gene ◽  
Whole Blood Samples ◽  
Pcr Targeting

Molecular methods are important tools in the diagnosis of bloodstream bacterial infections, in particular in patients treated with antimicrobial therapy, due to their quick turn-around time. Here we describe a new broad-range real-time PCR targeting the 23S rDNA gene and capable to detect as low as 10 plasmid copies per reaction of targeted bacterial 23S rDNA gene. Two commercially available DNA extraction kits were evaluated to assess their efficiency for the extraction of plasma and whole blood samples spiked with different amount of eitherStaphylococcus aureusorEscherichia coli, in order to find the optimal extraction method to be used. Manual QIAmp extraction method with enzyme pre-treatment resulted the most sensitive for detection of bacterial load. Sensitivity of this novel assay ranged between 10 and 103 CFU per PCR reaction forE. coliandS. aureusin human whole blood samples depending on the extraction methods used. Analysis of plasma samples showed a 10- to 100-fold reduction of bacterial 23S rDNA in comparison to the corresponding whole blood specimens, thus indicating that whole blood is the preferential sample type to be used in this real-time PCR protocol. Our results thus show that the 23S rDNA gene represents an optimal target for bacteria quantification in human whole blood.

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