scholarly journals Evaluation of the Biofire FilmArray BioThreat-E Test (v2.5) for Rapid Identification of Ebola Virus Disease in Heat-Treated Blood Samples Obtained in Sierra Leone and the United Kingdom

2015 ◽  
Vol 54 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Simon A. Weller ◽  
Daniel Bailey ◽  
Steven Matthews ◽  
Sarah Lumley ◽  
Angela Sweed ◽  
...  
Keyword(s):  
United Kingdom ◽  
Real Time ◽  
Sierra Leone ◽  
Real Time Pcr ◽  
Ebola Virus ◽  
Reference Method ◽  
Blood Samples ◽  
The United Kingdom ◽  
Heat Treated ◽  
Significant Difference

Rapid Ebola virus (EBOV) detection is crucial for appropriate patient management and care. The performance of the FilmArray BioThreat-E test (v2.5) using whole-blood samples was evaluated in Sierra Leone and the United Kingdom and was compared with results generated by a real-time Ebola Zaire PCR reference method. Samples were tested in diagnostic laboratories upon availability, included successive samples from individual patients, and were heat treated to facilitate EBOV inactivation prior to PCR. The BioThreat-E test had a sensitivity of 84% (confidence interval [CI], 64% to 95%) and a specificity of 89% (CI, 73% to 97%) in Sierra Leone (n= 60; 44 patients) and a sensitivity of 75% (CI, 19% to 99%) and a specificity of 100% (CI, 97% to 100%) in the United Kingdom (n= 108; 70 patients) compared to the reference real-time PCR. Statistical analysis (Fisher's exact test) indicated there was no significant difference between the methods at the 99% confidence level in either country. In 9 discrepant results (5 real-time PCR positives and BioThreat-E test negatives and 4 real-time PCR negatives and BioThreat-E test positives), the majority (n= 8) were obtained from samples with an observed or probable low viral load. The FilmArray BioThreat-E test (v2.5) therefore provides an attractive option for laboratories (either in austere field settings or in countries with an advanced technological infrastructure) which do not routinely offer an EBOV diagnostic capability.

scholarly journals Validation of iQ-Check E. coli O157:H7 Real-Time PCR Test Kit for Detection of Escherichia coli O157:H7 in Selected Foods

2009 ◽  
Vol 92 (4) ◽  
pp. 1095-1104 ◽  
Author(s):  
Wendy F Lauer ◽  
Sylvie Tymciu ◽  
Caroline D Sidi ◽  
Pierre Sonigo
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Ground Beef ◽  
Reference Method ◽  
Target Sequence ◽  
Apple Cider ◽  
E Coli ◽  
Test Kit ◽  
Significant Difference ◽  
The U.S

Abstract iQ-Check E. coli O157:H7 (Bio-Rad Laboratories, Hercules, CA) is a real-time PCR kit for detection of E. coli O157:H7 from selected foods. Specific fluorescent oligonucleotide probes are used to detect target DNA during the amplification, by hybridizing to the amplicons. These fluorescent probes are linked to a fluorophore which fluoresces only when hybridized to the target sequence. Three foods (ground beef, apple cider, fresh spinach) were selected to compare the performance of iQ-Check E. coli O157:H7 to the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook (MLG) reference method for ground beef and the U.S. Food and Drug Administration/Bacteriological Analytical Manual reference method for apple cider and fresh spinach. Three protocols were tested in this study: a shortened 8 h primary enrichment in buffered peptone water (BPW), a 24 h enrichment in BPW, and an enrichment in appropriate reference method enrichment broth. The iQ-Check E. coli O157:H7 method was able to identify more true/confirmed positive samples than the reference method. Inclusivity and exclusivity rates of the method were 100. iQ-Check E. coli O157:H7 performed as expected when minor procedural variations were introduced, validating the ruggedness of the method. There was no significant difference observed in performance over the shelf life of the kit.

scholarly journals Evaluation of Applied Biosystems MicroSEQ® Real-Time PCR System for Detection of Salmonella spp. in Food

2011 ◽  
Vol 94 (4) ◽  
pp. 1106-1116 ◽  
Author(s):  
Priya Balachandran ◽  
Yanxiang Cao ◽  
Lily Wong ◽  
Manohar R Furtado ◽  
Olga V Petrauskene ◽  
...  
Keyword(s):  
Real Time ◽  
Study Design ◽  
Real Time Pcr ◽  
Detection System ◽  
Peanut Butter ◽  
Reference Method ◽  
Black Pepper ◽  
Salmonella Spp ◽  
Culture Methods ◽  
Significant Difference

Abstract Real-time PCR methods for detecting foodborne pathogens offer the advantages of simplicity and quick time-to-results compared to traditional culture methods. In this study, the MicroSEQ® real-time PCR system was evaluated for detection of Salmonella spp. in 10 different food matrixes following the AOAC Research Institute's Performance Tested MethodSM validation program. In addition, the performance of the MicroSEQ system was evaluated for the detection of Salmonella in peanut butter as a part of the Emergency Response Validation Program sponsored by the AOAC Research Institute. The system was compared to the ISO 6579 reference method using a paired-study design for detecting Salmonella spp. in raw ground beef, raw chicken, raw shrimp, Brie cheese, shell eggs, cantaloupe, chocolate, black pepper, dry infant formula, and dry pet food. For the peanut butter study, the system was compared to the U.S. Food and Drug Administration's Bacteriological Analytical Manual procedures using an unpaired-study design. No significant difference in performance was observed between the MicroSEQ Salmonella spp. detection system and the corresponding reference methods for all 11 food matrixes. The MicroSEQ system detected all Salmonella strains tested, while showing good discrimination against detection of an exclusivity panel of 30 strains, with high accuracy.

Interlaboratory Validation for a Real-Time PCR Salmonella Detection Method Using the ABI 7500 FAST Real-Time PCR System

2015 ◽  
Vol 78 (6) ◽  
pp. 1119-1124 ◽  
Author(s):  
CHORNG-MING CHENG ◽  
TARA DORAN ◽  
WEN LIN ◽  
KAI-SHUN CHEN ◽  
DONNA WILLIAMS-HILL ◽  
...  
Keyword(s):  
Real Time ◽  
Internal Control ◽  
Real Time Pcr ◽  
Detection Method ◽  
Reference Method ◽  
Network Member ◽  
Fast System ◽  
Enhanced Sensitivity ◽  
Significant Difference ◽  
Chili Powder

Sixteen FERN (Food Emergency Response Network) member laboratories collaborated in this study to verify extension of the real-time PCR Salmonella detection method originally designed for the single-tube Cepheid SmartCycler II and validated against the Salmonella method of the U.S. Food and Drug Administration Bacteriological Analytical Manual to the Applied Biosystems (ABI) 7500 FAST Real-Time PCR system multiwell plate platform. Four foods were selected for this study: chili powder, soft cheese, fish, and tomatoes; these foods represent products that are commonly analyzed for the presence of Salmonella for regulatory purposes. Each food consisted of six uninoculated control samples, six samples inoculated with low Salmonella levels (target 1 to 5 CFU/25 g), and six samples inoculated with high levels (target 10 to 50 CFU/25 g). All samples were tested for Salmonella using the 24-h quantitative PCR (qPCR) method for detecting Salmonella, which utilizes modified buffered peptone water as the sole enrichment medium and an internal control for the qPCR. Each of these 18 samples was individually analyzed for Salmonella by the collaborating laboratories using both the ABI 7500 FAST system (alternative method) and the SmartCycler II system (reference method). Statistical analysis of the data revealed no significant difference (P ≥ 0.05) between these two qPCR platforms except for the chili powder samples. The differences noted with chili powder (P = 0.0455) were attributed to the enhanced sensitivity of the ABI 7500 FAST system compared with the SmartCycler II system. The detection limit of both qPCR methods was 0.02 to 0.15 CFU/g. These results provide a solid basis for extending the 24-h qPCR Salmonella method to the ABI 7500 FAST system for high-throughput detection of Salmonella in foods.

iQ-Check Listeria spp. Real-Time PCR Test Kit

2013 ◽  
Vol 96 (3) ◽  
pp. 508-515
Author(s):  
Wendy F Lauer ◽  
Jean-Philippe Tourniaire
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Reference Method ◽  
Sampling Area ◽  
Fermented Sausage ◽  
Low Level ◽  
Test Kit ◽  
Significant Difference ◽  
High Level ◽  
Health Canada

Abstract A comparative evaluation study of the Bio-Rad® iQ-Check™Listeria species Kit (Bio-Rad Laboratories, Hercules, CA) was conducted at Q Laboratories, Inc., Cincinnati, OH. iQ-Check is a rapid method based on real-time PCR amplification and detection of all species of Listeria, including L. grayi, in food and environmental samples. The iQ-Check method was compared to the Health Canada MFHPB-30 reference method for the analysis of five ready-to-eat meats—deli turkey, hot dogs, liver paté, raw fermented sausage, and deli ham—and one stainless steel surface. Each food matrix was analyzed at two contamination levels: a low level at 0.2–2 CFU/25 g and a high level at 2–5 CFU/25 g. The environmental surfaces were analyzed at a low level of 0.2–2 CFU/5 cm2 sampling area and a high level of 2–5 CFU/5 cm2 sampling area. There were 20 replicates per contamination level and five control replicates at 0 CFU/25 g or 0 CFU/5 cm2 sampling area (uninoculated). All samples that were detected by iQ-Check were subsequently confirmed by reference method protocol. There was no significant difference in the number of positive samples detected by the iQ-Check Listeria spp. Kit in comparison to the Health Canada MFHPB-30 method for all matrixes tested.

Detection of Salmonella species in a Variety of Foods by the DuPont™ BAX® System Real-Time PCR Assay for Salmonella: First Action 2013.02

2014 ◽  
Vol 97 (3) ◽  
pp. 868-875 ◽  
Author(s):  
F Morgan Wallace ◽  
Bridget Andaloro ◽  
Dawn Fallon ◽  
Nisha Corrigan ◽  
Stephen Varkey ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Orange Juice ◽  
Collaborative Study ◽  
Reference Method ◽  
Probability Of Detection ◽  
Test Method ◽  
Pcr Assay ◽  
Test Portion ◽  
Significant Difference

Abstract A multilaboratory study was conducted to evaluate the ability of the DuPont™ BAX® System Real-Time PCR Assay for Salmonella to detect the target species in a variety of foods and environmental surfaces. Internal validation studies were performed by DuPont Nutrition & Health on 24 different sample types to demonstrate the reliability of the test method among a wide variety of sample types. Two of these matrixes—pork and turkey frankfurters and pasteurized, not-from-concentrate orange juice without pulp—were each evaluated in 14 independent laboratories as part of the collaborative study to demonstrate repeatability and reproducibility of the internal laboratory results independent of the end user. Frankfurter samples were evaluated against the U. S. Department of Agriculture, Food Safety and Inspection Service reference method as a paired study, while orange juice samples were evaluated against the U. S. Food and Drug Administration reference method as an unpaired study, using a proprietary media for the test method. Samples tested in this study were artificially inoculated with a Salmonella strain at levels expected to produce low (0.2–2.0 CFU/test portion) or high (5 CFU/test portion) spike levels on the day of analysis. For each matrix, the collaborative study failed to show a statistically significant difference between the candidate method and the reference method using the probability of detection statistical model.

Effect of Concentration of Trisodium Citrate Anticoagulant on Calculation of the International Normalised Ratio and the International Sensitivity Index of Thromboplastin

1994 ◽  
Vol 72 (01) ◽  
pp. 084-088 ◽  
Author(s):  
E M Duncan ◽  
C R Casey ◽  
B M Duncan ◽  
J V Lloyd
Keyword(s):  
Reference Material ◽  
Oral Anticoagulants ◽  
Reference Method ◽  
Trisodium Citrate ◽  
Sensitivity Index ◽  
Blood Samples ◽  
Orthogonal Regression ◽  
Significant Difference ◽  
International Normalised Ratio ◽  
International Sensitivity Index

SummaryThe aim of this study was to determine whether the concentration of trisodium citrate used to anticoagulate blood has an effect on the INR of the sample and the ISI of the thromboplastin. Five thromboplastins including and Australian reference material were used to measure the prothrombin time of normal and patient samples collected into two concentrations of trisodium citrate - 109 mM and 129 mM. There was no effect of citrate concentration on the INRs determined with the reference material. However for the other four thromboplastins there was a significant difference between INRs for the two citrate groups. The prothrombin times of the samples collected into 129 mM were longer than those collected into 109 mM. This difference was only slight in normal plasma but more marked in patients receiving oral anticoagulants, causing the INRs for patient plasmas collected into 129 mM citrate to be higher then the corresponding samples collected into 109 mM citrate.From orthogonal regression of log prothrombin times by the reference method against each thromboplastin, we found that the ISI for each thromboplastin was approximately 10% lower when determined with samples collected into 129 mM citrate than with samples collected into 109 mM. These results suggest that the concentration of trisodium citrate used for collection of blood samples can affect the calculation of the INR and the calibration of the ISI of thromboplastin. This was found both for commercial thromboplastins prepared by tissue extraction and for a recombinant tissue factor.

scholarly journals Listening to Slugs: Acceptability and Consumption of Molluscicide Pellets by the Grey Field Slug, Deroceras reticulatum

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 548
Author(s):  
Samantha Mirhaya de Silva ◽  
David Chesmore ◽  
Jack Smith ◽  
Gordon Port
Keyword(s):  
United Kingdom ◽  
Economic Impact ◽  
Active Ingredient ◽  
Crop Protection ◽  
Crop Plants ◽  
Deroceras Reticulatum ◽  
The United Kingdom ◽  
Ferric Phosphate ◽  
Significant Difference

Gastropod damage to crop plants has a significant economic impact on agricultural and horticultural industries worldwide, with the Grey Field Slug (Deroceras reticulatum (Müller)) considered the main mollusc pest in the United Kingdom and in many other temperate areas. The prevailing form of crop protection is pellets containing the active ingredient, metaldehyde. Metaldehyde can cause paralysis and death in the mollusc, depending on the amount ingested. The paralysing effects may result in reduced pellet consumption. A greater understanding of metaldehyde consumption may reveal an area that can be manipulated using novel molluscicide formulations. Novel pellet types included commercial metaldehyde pellets coated so that metaldehyde is released more slowly. In both laboratory and arena trials, an audio sensor was used to record individual slugs feeding on a variety of pellet types, including commercially available toxic pellets (metaldehyde and ferric phosphate) and novel metaldehyde formulations. The sensor was used to record the length of each bite and the total number of bites. There was no significant difference in the length of bites between pellet types in laboratory trials. Novel pellets were not consumed more than commercial pellet types. Commercial pellet types did not differ in consumption.

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