scholarly journals Evaluation of different DNA extraction methods and loop-mediated isothermal amplification primers for the detection of Mycobacterium ulcerans in clinical specimens

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Anthony Ablordey ◽  
Evans Ahotor ◽  
Charles A. Narh ◽  
Sandra A. King ◽  
Isra Cruz ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Extraction Method ◽  
Point Of Care ◽  
Buruli Ulcer ◽  
Extraction Methods ◽  
Isothermal Amplification ◽  
Mycobacterium Ulcerans ◽  
Loop Mediated Isothermal Amplification ◽  
Dna Extraction Method ◽  
Dna Extraction Methods

Abstract Background Early diagnosis and treatment of Buruli ulcer is critical in order to avoid the debilitating effects of the disease. In this regard, the development of new diagnostic and point of care tools is encouraged. The loop-mediated isothermal amplification for the detection of Mycobacterium ulcerans represents one of the new tools with a good potential of being developed into a point of care test. There is however the need to standardize the assays, reduce sample preparation times, improve the detection/visualization system and optimize them for high-throughput screening, adaptable to low resourced laboratories. Methods In this study, we assessed two DNA extraction protocols (modified Boom and EasyNAT methods), three previously published LAMP primer sets (BURULI, MU 2404 and BU-LAMP), and compared the sensitivity and specificity of LAMP assays on three DNA amplification platforms. Results Our results show that Buruli ulcer diagnosis using primers targeting IS2404 for the LAMP method is sensitive (73.75–91.49%), depending on the DNA extraction method used. Even though the modified Boom DNA extraction method provided the best results, its instrumentation requirement prevent it from being field applicable. The EasyNAT method on the other hand is simpler and may represent the best method for DNA extraction in less resourced settings. Conclusions For further work on the development and use of LAMP tests for Buruli diagnosis, it is recommended that the BURULI sets of primers be used, as these yielded the best results in terms of sensitivity (87.50–91.49%) and specificity (89.23–100%), depending on the DNA extraction methods used.

scholarly journals Evaluation of Rapid Extraction Methods Coupled with a Recombinase Polymerase Amplification Assay for Point-of-Need Diagnosis of Post-Kala-Azar Dermal Leishmaniasis

2020 ◽  
Vol 5 (2) ◽  
pp. 95 ◽  
Author(s):  
Rajashree Chowdhury ◽  
Prakash Ghosh ◽  
Md. Anik Ashfaq Khan ◽  
Faria Hossain ◽  
Khaledul Faisal ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Extraction Method ◽  
Extraction Methods ◽  
Recombinase Polymerase Amplification ◽  
National Guidelines ◽  
Diagnostic Efficacy ◽  
Rapid Extraction ◽  
Kala Azar ◽  
Dna Extraction Method ◽  
Dna Extraction Methods

To detect Post-kala-azar leishmaniasis (PKDL) cases, several molecular methods with promising diagnostic efficacy have been developed that involve complicated and expensive DNA extraction methods, thus limiting their application in resource-poor settings. As an alternative, we evaluated two rapid DNA extraction methods and determined their impact on the detection of the parasite DNA using our newly developed recombinase polymerase amplification (RPA) assay. Skin samples were collected from suspected PKDL cases following their diagnosis through national guidelines. The extracted DNA from three skin biopsy samples using three different extraction methods was subjected to RPA and qPCR. The qPCR and RPA assays exhibited highest sensitivities when reference DNA extraction method using Qiagen (Q) kit was followed. In contrast, the sensitivity of the RPA assay dropped to 76.7% and 63.3%, respectively, when the boil & spin (B&S) and SpeedXtract (SE) rapid extraction methods were performed. Despite this compromised sensitivity, the B&S-RPA technique yielded an excellent agreement with both Q-qPCR (k = 0.828) and Q-RPA (k = 0.831) techniques. As expected, the reference DNA extraction method was found to be superior in terms of diagnostic efficacy. Finally, to apply the rapid DNA extraction methods in resource-constrained settings, further methodological refinement is warranted to improve DNA yield and purity through rigorous experiments.

scholarly journals Toward standards in clinical microbiome studies: comparison of three DNA extraction methods and two bioinformatic pipelines

2019 ◽  
Author(s):  
Q.R. Ducarmon ◽  
B.V.H. Hornung ◽  
A.R. Geelen ◽  
E.J. Kuijper ◽  
R.D. Zwittink
Keyword(s):  
Dna Extraction ◽  
Extraction Method ◽  
Bacterial Biomass ◽  
Extraction Methods ◽  
Rrna Gene ◽  
Method Choice ◽  
Advantages And Disadvantages ◽  
Dna Extraction Method ◽  
Dna Extraction Methods ◽  
Negative Controls

ABSTRACTWhen studying the microbiome using next generation sequencing, DNA extraction method, sequencing procedures and bioinformatic processing are crucial to obtain reliable data. Method choice has been demonstrated to strongly affect the final biological interpretation. We assessed the performance of three DNA extraction methods and two bioinformatic pipelines for bacterial microbiota profiling through 16S rRNA gene amplicon sequencing, using positive and negative controls for DNA extraction and sequencing, and eight different types of high- or low-biomass samples. Performance was evaluated based on quality control passing, DNA yield, richness, diversity and compositional profiles. All DNA extraction methods retrieved the theoretical relative bacterial abundance with maximum three-fold change, although differences were seen between methods, and library preparation and sequencing induced little variation. Bioinformatic pipelines showed different results for estimating richness, but diversity and compositional profiles were comparable. DNA extraction methods were successful for feces and oral swabs and variation induced by DNA extraction methods was lower than inter-subject (biological) variation. For low-biomass samples, a mixture of genera present in negative controls and sample-specific genera, possibly representing biological signal, were observed. We conclude that the tested bioinformatic pipelines perform equally with pipeline-specific advantages and disadvantages. Two out of three extraction methods performed equally well, while one method was less accurate regarding retrieval of compositional profiles. Lastly, we demonstrate the importance of including negative controls when analyzing low bacterial biomass samples.IMPORTANCEMethod choice throughout the workflow of a microbiome study, from sample collection to DNA extraction and sequencing procedures, can greatly affect results. This study evaluated three different DNA extraction methods and two bioinformatic pipelines by including positive and negative controls, and various biological specimens. By identifying an optimal combination of DNA extraction method and bioinformatic pipeline use, we hope to contribute to increased methodological consistency in microbiome studies. Our methods were not only applied to commonly studied samples for microbiota analysis, e.g. feces, but also for more rarely studied, low-biomass samples. Microbiota composition profiles of low-biomass samples (e.g. urine and tumor biopsies) were not always distinguishable from negative controls, or showed partial overlap, confirming the importance of including negative controls in microbiome studies, especially when low bacterial biomass is expected.

scholarly journals Evaluation of a Loop-Mediated Isothermal Amplification Suite for the Rapid, Reliable, and Robust Detection of Shiga Toxin-Producing Escherichia coli in Produce

2014 ◽  
Vol 80 (8) ◽  
pp. 2516-2525 ◽  
Author(s):  
Fei Wang ◽  
Qianru Yang ◽  
Yinzhi Qu ◽  
Jianghong Meng ◽  
Beilei Ge
Keyword(s):  
Escherichia Coli ◽  
Dna Extraction ◽  
Shiga Toxin ◽  
The United States ◽  
Extraction Methods ◽  
Isothermal Amplification ◽  
Detection Methods ◽  
Robust Detection ◽  
Loop Mediated Isothermal Amplification ◽  
Dna Extraction Methods

ABSTRACTShiga toxin-producingEscherichia coli(STEC) strains are a leading cause of produce-associated outbreaks in the United States. Rapid, reliable, and robust detection methods are needed to better ensure produce safety. We recently developed a loop-mediated isothermal amplification (LAMP) suite for STEC detection. In this study, the STEC LAMP suite was comprehensively evaluated against real-time quantitative PCR (qPCR) using a large panel of bacterial strains (n= 156) and various produce items (several varieties of lettuce, spinach, and sprouts). To simulate real-world contamination events, produce samples were surface inoculated with a low level (1.2 to 1.8 CFU/25 g) of individual STEC strains belonging to seven serogroups (O26, O45, O103, O111, O121, O145, and O157) and held at 4°C for 48 h before testing. Six DNA extraction methods were also compared using produce enrichment broths. All STEC targets and their subtypes were accurately detected by the LAMP suite. The detection limits were 1 to 20 cells per reaction in pure culture and 105to 106CFU per 25 g (i.e., 103to 104CFU per g) in produce, except for strains harboring thestx2c,eae-β, andeae-θ subtypes. After 6 to 8 h of enrichment, the LAMP suite achieved accurate detection of low levels of STEC strains of variousstx2andeaesubtypes in lettuce and spinach varieties but not in sprouts. A similar trend of detection was observed for qPCR. The PrepMan Ultra sample preparation reagent yielded the best results among the six DNA extraction methods. This research provided a rapid, reliable, and robust method for detecting STEC in produce during routine sampling and testing. The challenge with sprouts detection by both LAMP and qPCR calls for special attention to further analysis.

scholarly journals Toward Standards in Clinical Microbiota Studies: Comparison of Three DNA Extraction Methods and Two Bioinformatic Pipelines

mSystems ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Q. R. Ducarmon ◽  
B. V. H. Hornung ◽  
A. R. Geelen ◽  
E. J. Kuijper ◽  
R. D. Zwittink
Keyword(s):  
Dna Extraction ◽  
Extraction Method ◽  
Bacterial Biomass ◽  
Extraction Methods ◽  
Rrna Gene ◽  
Method Choice ◽  
Advantages And Disadvantages ◽  
Dna Extraction Method ◽  
Dna Extraction Methods ◽  
Negative Controls

ABSTRACT When studying the microbiome using next-generation sequencing, the DNA extraction method, sequencing procedures, and bioinformatic processing are crucial to obtain reliable data. Method choice has been demonstrated to strongly affect the final biological interpretation. We assessed the performance of three DNA extraction methods and two bioinformatic pipelines for bacterial microbiota profiling through 16S rRNA gene amplicon sequencing, using positive and negative controls for DNA extraction and sequencing and eight different types of high- or low-biomass samples. Performance was evaluated based on quality control passing, DNA yield, richness, diversity, and compositional profiles. All DNA extraction methods retrieved the theoretical relative bacterial abundance with a maximum 3-fold change, although differences were seen between methods, and library preparation and sequencing induced little variation. Bioinformatic pipelines showed different results for observed richness, but diversity and compositional profiles were comparable. DNA extraction methods were successful for feces and oral swabs, and variation induced by DNA extraction methods was lower than intersubject (biological) variation. For low-biomass samples, a mixture of genera present in negative controls and sample-specific genera, possibly representing biological signal, were observed. We conclude that the tested bioinformatic pipelines perform equally, with pipeline-specific advantages and disadvantages. Two out of three extraction methods performed equally well, while one method was less accurate regarding retrieval of compositional profiles. Lastly, we again demonstrate the importance of including negative controls when analyzing low-bacterial-biomass samples. IMPORTANCE Method choice throughout the workflow of a microbiome study, from sample collection to DNA extraction and sequencing procedures, can greatly affect results. This study evaluated three different DNA extraction methods and two bioinformatic pipelines by including positive and negative controls and various biological specimens. By identifying an optimal combination of DNA extraction method and bioinformatic pipeline use, we hope to contribute to increased methodological consistency in microbiota studies. Our methods were applied not only to commonly studied samples for microbiota analysis, e.g., feces, but also to more rarely studied, low-biomass samples. Microbiota composition profiles of low-biomass samples (e.g., urine and tumor biopsy specimens) were not always distinguishable from negative controls, or showed partial overlap, confirming the importance of including negative controls in microbiota studies, especially when low bacterial biomass is expected.

scholarly journals Comparative investigation of DNA extraction methods in black gram (Vigna mungo (L.)

2019 ◽  
Author(s):  
M. . Prakash ◽  
B. . Priyadharshini ◽  
M. . Vignesh ◽  
R. . Anandan
Keyword(s):  
Dna Extraction ◽  
Extraction Method ◽  
Large Scale ◽  
Dna Isolation ◽  
Extraction Methods ◽  
Comparative Investigation ◽  
Black Gram ◽  
Dna Extraction Method ◽  
Ctab Method ◽  
Dna Extraction Methods

Isolation of intact, double stranded, pure and non- contaminated genomic DNA is prerequisite for large scale genotyping analysis including DNA-banks. Three methods of DNA isolation (Dellaporta, CTAB and Hi-PurAg DNA isolation kits) from 25 black gram genotypes were compared in terms of the yield, purity, integrity, and stability of extracted DNA. Purity and quantification of isolated DNA samples was confirmed by using the UV nano-spectrophotometer at OD260/280 and the same is confirmed based by agarose gel electrophoresis. The CTAB method showed the best results followed by Hi-PurAg and Dellaporta method. The CTAB DNA extraction method was found to be the most efficient DNA extraction method, capable of providing high quality, pure and stable DNA and could be used for various molecular related works. All the 25 black gram genotypes for this research gave good yield of DNA from the established modified CTAB protocol.

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