scholarly journals Wildlife pathogen detection: evaluation of alternative DNA extraction protocols

2021 ◽  
Author(s):  
Vasiliki Mantzana-Oikonomaki ◽  
Martine Maan ◽  
Joana Sabino-Pinto
Keyword(s):  
Dna Extraction ◽  
Pathogen Detection ◽  
Detection Efficiency ◽  
Quantitative Polymerase Chain Reaction ◽  
Wildlife Disease ◽  
False Negatives ◽  
Optimal Method ◽  
Spin Column ◽  
Pre Treatment ◽  
Wildlife Pathogens

Abstract Accurate detection of wildlife pathogens is critical in wildlife disease research. False negatives or positives can have catastrophic consequences for conservation and disease-mitigation decisions. Quantitative polymerase chain reaction is commonly used for molecular detection of wildlife pathogens. The reliability of this method depends on the effective extraction of the pathogen’s DNA from host samples. A wildlife disease that has been in the centre of conservationist’s attention is the amphibian disease Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). Here, we compare the efficiency of a spin column extraction kit (QIAGEN), commonly used in Bd DNA extraction, to an alternative spin column kit (BIOKÈ) used in extractions from other types of samples, which is considerably cheaper but not typically used for Bd DNA extraction. Additionally, we explore the effect of an enzymatic pre-treatment on detection efficiency. Both methods showed similar efficiency when extracting Bd DNA from zoospores from laboratory-created cell-cultures, as well as higher efficiency when combined with the enzymatic pre-treatment. Our results indicate that selecting the optimal method for DNA extraction is essential to ensure minimal false negatives and reduce project costs.

Detectability vs. time and costs in pooled DNA extraction of cutaneous swabs: a study on the amphibian chytrid fungi

2019 ◽  
Vol 40 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Joana Sabino-Pinto ◽  
E. Tobias Krause ◽  
Molly C. Bletz ◽  
An Martel ◽  
Frank Pasmans ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Pathogen Detection ◽  
Batrachochytrium Dendrobatidis ◽  
Quantitative Polymerase Chain Reaction ◽  
Large Fraction ◽  
Work Load ◽  
Detection Sensitivity ◽  
Pooled Dna ◽  
Reaction Volumes ◽  
User Friendly

Abstract Epidemiology relies on understanding the distribution of pathogens which often can be detected through DNA-based techniques, such as quantitative Polymerase Chain Reaction (qPCR). Typically, the DNA of each individual sample is separately extracted and undergoes qPCR analysis. However, when performing field surveys and long-term monitoring, a large fraction of the samples is generally expected to be negative, especially in geographical areas still considered free of the pathogen. If pathogen detection within a population – rather than determining its individual prevalence – is the focus, work load and monetary costs can be reduced by pooling samples for DNA extraction. We test and refine a user-friendly technique where skin swabs can be pooled during DNA extraction to detect the amphibian chytrid fungi, Batrachochytrium dendrobatidis and B. salamandrivorans (Bsal). We extracted pools with different numbers of samples (from one to four swabs), without increasing reaction volumes, and each pool had one sample inoculated with a predetermined zoospore amount. Pool size did not reduce the ability to detect the two fungi, except if inoculated with extremely low zoospore amounts (one zoospore). We confirm that pooled DNA extraction of cutaneous swabs can substantially reduce processing time and costs without minimizing detection sensitivity. This is of relevance especially for the new emerging pathogen Bsal, for which pooled DNA extraction had so far not been tested and massive monitoring efforts in putatively unaffected regions are underway.

scholarly journals The Rapid Antigen Detection Test for SARS-CoV-2 Underestimates the Identification of COVID-19 Positive Cases and Compromises the Diagnosis of the SARS-CoV-2 (K417N/T, E484K, and N501Y) Variants

2022 ◽  
Vol 9 ◽  
Author(s):  
Carlos Barrera-Avalos ◽  
Roberto Luraschi ◽  
Eva Vallejos-Vidal ◽  
Andrea Mella-Torres ◽  
Felipe Hernández ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Quantitative Polymerase Chain Reaction ◽  
Detection Sensitivity ◽  
Nucleotide Polymorphisms ◽  
False Negatives ◽  
Single Nucleotide ◽  
Rapid Antigen Detection Test ◽  
Current Scenario ◽  
Variant Detection ◽  
Polymerase Chain

Timely detection of severe acute respiratory syndrome due to coronavirus 2 (SARS-CoV-2) by reverse transcription quantitative polymerase chain reaction (RT-qPCR) has been the gold- strategy for identifying positive cases during the current pandemic. However, faster and less expensive methodologies are also applied for the massive diagnosis of COVID-19. In this way, the rapid antigen test (RAT) is widely used. However, it is necessary to evaluate its detection efficiency considering the current pandemic context with the circulation of new viral variants. In this study, we evaluated the sensitivity and specificity of RAT (SD BIOSENSOR, South Korea), widely used for testing and SARS-CoV-2 diagnosis in Santiago of Chile. The RAT showed a 90% (amplification range of 20 ≤ Cq <25) and 10% (amplification range of 25 ≤ Cq <30) of positive SARS-CoV-2 cases identified previously by RT-qPCR. Importantly, a 0% detection was obtained for samples within a Cq value>30. In SARS-CoV-2 variant detection, RAT had a 42.8% detection sensitivity in samples with RT-qPCR amplification range 20 ≤ Cq <25 containing the single nucleotide polymorphisms (SNP) K417N/T, N501Y and E484K, associated with beta or gamma SARS-CoV-2 variants. This study alerts for the special attention that must be paid for the use of RAT at a massive diagnosis level, especially in the current scenario of appearance of several new SARS-CoV-2 variants which could generate false negatives and the compromise of possible viral outbreaks.

scholarly journals New Insights on NETosis Induced by Entamoeba histolytica: Dependence on ROS from Amoebas and Extracellular MPO Activity

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 974
Author(s):  
César Díaz-Godínez ◽  
Joshue Fabián Jorge-Rosas ◽  
Mario Néquiz ◽  
Santiago Martínez-Calvillo ◽  
Juan P. Laclette ◽  
...  
Keyword(s):  
Cell Surface ◽  
Nadph Oxidase ◽  
Entamoeba Histolytica ◽  
Pathogen Detection ◽  
Dependent Manner ◽  
Antimicrobial Proteins ◽  
Nadph Oxidase Activity ◽  
Mitochondrial Ros ◽  
Pre Treatment ◽  
Dose Dependent

NETosis is a neutrophil process involving sequential steps from pathogen detection to the release of DNA harboring antimicrobial proteins, including the central generation of NADPH oxidase dependent or independent ROS. Previously, we reported that NETosis triggered by Entamoeba histolytica trophozoites is independent of NADPH oxidase activity in neutrophils, but dependent on the viability of the parasites and no ROS source was identified. Here, we explored the possibility that E. histolytica trophozoites serve as the ROS source for NETosis. NET quantitation was performed using SYTOX® Green assay in the presence of selective inhibitors and scavengers. We observed that respiratory burst in neutrophils was inhibited by trophozoites in a dose dependent manner. Mitochondrial ROS was not also necessary, as the mitochondrial scavenger mitoTEMPO did not affect the process. Surprisingly, ROS-deficient amoebas obtained by pre-treatment with pyrocatechol were less likely to induce NETs. Additionally, we detected the presence of MPO on the cell surface of trophozoites after the interaction with neutrophils and found that luminol and isoluminol, intracellular and extracellular scavengers for MPO derived ROS reduced the amount of NET triggered by amoebas. These data suggest that ROS generated by trophozoites and processed by the extracellular MPO during the contact with neutrophils are required for E. histolytica induced NETosis.

scholarly journals Toxoplasma gondii and pre-treatment protocols for polymerase chain reaction analysis of milk samples: a field trial in sheep from Southern Italy

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Alice Vismarra ◽  
Elena Barilli ◽  
Maura Miceli ◽  
Carlo Mangia ◽  
Cristina Bacci ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Real Time ◽  
Dna Extraction ◽  
Real Time Pcr ◽  
Southern Italy ◽  
Raw Milk ◽  
Type I ◽  
Treatment Protocols ◽  
Milk Samples ◽  
Pre Treatment

Toxoplasmosis is a zoonotic disease caused by the protozoan <em>Toxoplasma gondii</em>. Ingestion of raw milk has been suggested as a risk for transmission to humans. Here the authors evaluated pre-treatment protocols for DNA extraction on <em>T. gondii</em> tachyzoite-spiked sheep milk with the aim of identifying the method that resulted in the most rapid and reliable PCR positivity. This protocol was then used to analyze milk samples form sheep from three different farms in southern Italy, including Real Time PCR for DNA quantification and PCR-RFLP for genotyping. The pre-treatment protocol using EDTA and Tris-HCl to remove casein gave the best results in the least amount of time compared to the others on spiked milk samples. One sample of 21 collected from sheep farms was positive on one-step PCR, Real Time PCR and resulted in a Type I genotype at one locus (SAG3). Milk usually contains a low number of tachyzoites and this could be a limiting factor for molecular identification. Our preliminary data has evaluated a rapid, cost-effective and sensitive protocol to treat milk before DNA extraction. The results of the present study also confirm the possibility of <em>T. gondii</em> transmission through consumption of raw milk and its unpasteurized derivatives.

scholarly journals Determining the optimal method for DNA isolation from fruit jams

2018 ◽  
Vol 36 (No. 2) ◽  
pp. 126-132
Author(s):  
Sovová Tereza ◽  
Křížová Barbora ◽  
Ovesná Jaroslava
Keyword(s):  
Dna Extraction ◽  
Dna Isolation ◽  
Extraction Methods ◽  
Food Samples ◽  
Pcr Analysis ◽  
Uv Spectrophotometry ◽  
Pcr Assay ◽  
Optimal Method ◽  
Ctab Method ◽  
Dna Extraction Methods

DNA extraction is a crucial step in PCR analysis especially when analysing food samples that can be degraded and can potentially contain PCR-inhibiting substances. In this study, we compared the suitability of three DNA extraction methods – two kits: DNeasy<sup>®</sup> Plant Mini Kit and NucleoSpin<sup>®</sup> Food, and the CTAB method – for DNA extraction from commercial fruit jams. Fourteen jams with different contents of fruit, sugar and other additives were extracted in triplicate using the above-mentioned methods directly and after a washing step. The concentration and optical density were analysed using UV spectrophotometry and the amplifiability of the obtained DNA was evaluated using a PCR assay targeting a sequence coding for chloroplast tRNA-Leu. Samples isolated using the NucleoSpin<sup>®</sup> Food kit contained non-amplifiable DNA in eight cases, and samples isolated using the CTAB method could not be quantified. The DNeasy<sup>®</sup> Plant Mini Kit thus proved to be the most suitable method, since well-amplifiable DNA was obtained for all the analysed samples.

scholarly journals Comparason of extraction methods for PCR detection of Burkholderia cepacia complex (BCC) from cystic fibrosis patients

Open Medicine ◽  
2008 ◽  
Vol 3 (2) ◽  
pp. 157-162
Author(s):  
Koray Ergunay ◽  
Pinar Yurdakul ◽  
Burcin Sener ◽  
Ugur Ozcelik ◽  
Erdem Karabulut ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Burkholderia Cepacia ◽  
Limit Of Detection ◽  
Direct Detection ◽  
Extraction Methods ◽  
Rapid Identification ◽  
Burkholderia Cepacia Complex ◽  
Assay Sensitivity ◽  
Spin Column ◽  
Significant Difference

AbstractDirect detection of Burkholderia cepacia complex (BCC) and its genomovars from sputum by molecular tests emerges as a method for rapid identification. In this study, four DNA extraction methods were evaluated for the identification for BCC from sputum of CF patients. Sputa from 28 CF patients were aliquoted and spiked with BCC reference strain. Boiling, phenol-chloroform, CTAB methods and a commercial spin column kit was used for DNA extraction. Total DNA yields were determined by spectrophotometry and single-round recA PCR was used for detection of BCC. No significant difference was observed in DNA yields from different extraction methods. Lower limit of detection for recA PCR was determined as 106 cfu/ml. Amplification was observed in 7/16 (43.7%) of sputa for boiling, 8/16 (50%) of sputa for CTAB and 13/16 (81.2%) of sputa for phenol-chloroform method and spin column kit in the assay sensitivity range determined in the study. Phenol-chloroform and commercial spin column kit were found to be better suited for DNA purification from sputum of CF patients for BCC identification. Diagnostic impact of single-round recA PCR directly from sputum was limited to chronically-infected patients.

Evaluation of alternative DNA extraction processes and real-time PCR for detecting Cryptosporidium parvum in drinking water

2015 ◽  
Vol 15 (6) ◽  
pp. 1295-1303
Author(s):  
Gina H. Kimble ◽  
Vincent R. Hill ◽  
James E. Amburgey
Keyword(s):  
Drinking Water ◽  
Real Time ◽  
Dna Extraction ◽  
Cryptosporidium Parvum ◽  
Water Samples ◽  
Real Time Pcr ◽  
Extraction Procedure ◽  
The United States ◽  
Detection Sensitivity ◽  
Spin Column

USEPA Method 1623 is the standard method in the United States for the detection of Cryptosporidium in water samples, but quantitative real-time polymerase chain reaction (qPCR) is an alternative technique that has been successfully used to detect Cryptosporidium in aqueous matrices. This study examined various modifications to a commercial nucleic acid extraction procedure in order to enhance PCR detection sensitivity for Cryptosporidium. An alternative DNA extraction buffer allowed for qPCR detection at lower seed levels than a commercial extraction kit buffer. In addition, the use of a second spin column cycle produced significantly better detection (P = 0.031), and the volume of Tris–EDTA buffer significantly affected crossing threshold values (P = 0.001). The improved extraction procedure was evaluated using 10 L of tap water samples processed by ultrafiltration, centrifugation and immunomagnetic separation. Mean recovery for the sample processing method was determined to be 41% using microscopy and 49% by real-time PCR (P = 0.013). The results of this study demonstrate that real-time PCR can be an effective alternative for detecting and quantifying Cryptosporidium parvum in drinking water samples.

scholarly journals Development of an Efficient Real-Time Quantitative PCR Protocol for Detection ofXanthomonas arboricolapv. pruni inPrunusSpecies

2010 ◽  
Vol 77 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Ana Palacio-Bielsa ◽  
Jaime Cubero ◽  
Miguel A. Cambra ◽  
Raquel Collados ◽  
Isabel M. Berruete ◽  
...  
Keyword(s):  
Real Time ◽  
Dna Extraction ◽  
Plant Material ◽  
Pathogen Detection ◽  
Plant Protection ◽  
The European Union ◽  
Real Time Quantitative Pcr ◽  
Field Samples ◽  
Mediterranean Plant ◽  
Different Origins

ABSTRACTXanthomonas arboricolapv. pruni, the causal agent of bacterial spot disease of stone fruit, is considered a quarantine organism by the European Union and the European and Mediterranean Plant Protection Organization (EPPO). The bacterium can undergo an epiphytic phase and/or be latent and can be transmitted by plant material, but currently, only visual inspections are used to certify plants as beingX. arboricolapv. pruni free. A novel and highly sensitive real-time TaqMan PCR detection protocol was designed based on a sequence of a gene for a putative protein related to an ABC transporter ATP-binding system inX. arboricolapv. pruni. Pathogen detection can be completed within a few hours with a sensitivity of 102CFU ml−1, thus surpassing the sensitivity of the existing conventional PCR. Specificity was assessed forX. arboricolapv. pruni strains from different origins as well as for closely relatedXanthomonasspecies, non-Xanthomonasspecies, saprophytic bacteria, and healthyPrunussamples. The efficiency of the developed protocol was evaluated with field samples of 14Prunusspecies and rootstocks. For symptomatic leaf samples, the protocol was very efficient even when washed tissues of the leaves were directly amplified without any previous DNA extraction. For samples of 117 asymptomatic leaves and 285 buds, the protocol was more efficient after a simple DNA extraction, andX. arboricolapv. pruni was detected in 9.4% and 9.1% of the 402 samples analyzed, respectively, demonstrating its frequent epiphytic or endophytic phase. This newly developed real-time PCR protocol can be used as a quantitative assay, offers a reliable and sensitive test forX. arboricolapv. pruni, and is suitable as a screening test for symptomatic as well as asymptomatic plant material.

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