Development of detection method for edible silkworm (Bombyx mori) using real-time PCR

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.

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Next day Salmonella spp. detection method based on real-time PCR for meat, dairy and vegetable food products

International Journal of Food Microbiology ◽

10.1016/j.ijfoodmicro.2014.03.021 ◽

2014 ◽

Vol 184 ◽

pp. 113-120 ◽

Cited By ~ 31

Author(s):

David Rodriguez-Lazaro ◽

Patricia Gonzalez-García ◽

Elisabetta Delibato ◽

Dario De Medici ◽

Rosa Maria García-Gimeno ◽

...

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Detection Method ◽

Food Products ◽

Salmonella Spp ◽

Vegetable Food

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Performance comparison of two malaria rapid diagnostic test with real time polymerase chain reaction and gold standard of microscopy detection method

Infectious Disease Reports ◽

10.4081/idr.2020.8731 ◽

2020 ◽

Author(s):

Puspa Wardhani ◽

Trieva Verawaty Butarbutar ◽

Christophorus Oetama Adiatmaja ◽

Amarensi Milka Betaubun ◽

Nur Hamidah ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Real Time ◽

Diagnostic Test ◽

Real Time Pcr ◽

Predictive Value ◽

Gold Standard ◽

Detection Method ◽

Rt Pcr ◽

Chain Reaction ◽

Polymerase Chain

Background: The diagnostic test for malaria is mostly based on Rapid Diagnostic Test (RDT) and detection by microscopy. Polymerase Chain Reaction (PCR) is also a sensitive detection method that can be considered as a diagnostic tool. The outcome of malaria microscopy detection depends on the examiner's ability and experience. Some RDT has been distributed in Indonesia, which needs to be evaluated for their results. Objective: This study aimed to compare the performance of RightSign RDT and ScreenPlus RDT for detection of Plasmodium in human blood. We used specific real-time polymerase chain reaction abTESTMMalaria qPCRII) and gold standard of microscopy detection method to measure diagnostic efficiency. Methods: Blood specimens were evaluated using RightSign RDT, ScreenPlus RDT, Microscopy detection, and RT-PCR as the protocol described. The differences on specificity (Sp), sensitivity (Sn), positive predictive value (PPV), and negative predictive value (NPV) were analyzed using McNemar and Kruskal Wallis analysis. Results: A total of 105 subjects were recruited. Based on microscopy test, RightSign RDT had sensitivity, Specificity, PPV, NPV, 100%, 98%, 98.2%, 100%, respectively. ScreenPlus showed 100% sensitivity, 98% specificity, 98.2% PPV, 100% NPV. The sensitivity of both RDTs became lower (75%) and the specificity higher (100 %) when using real-time PCR. Both RDTs showed a 100% agreement. RT-PCR detected higher mix infection when compared to microscopy and RDTs. Conclusion: RightSign and ScreenPlus RDT have excellent performance when using microscopy detection as a gold standard. Real-time PCR method can be considered as a confirmation tool for malaria diagnosis.

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Development of a DNA-Based Detection Method for Cocos Nucifera Using TaqMan™ Real-Time PCR

Foods ◽

10.3390/foods9030332 ◽

2020 ◽

Vol 9 (3) ◽

pp. 332

Author(s):

Jasmin Wrage ◽

Oxana Kleyner ◽

Sascha Rohn ◽

Jürgen Kuballa

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Detection Method ◽

Immunoglobulin E ◽

Limit Of Detection ◽

Cocos Nucifera ◽

Cross Reactivity ◽

Pcr Assay ◽

Probe System ◽

Ige Mediated

So far, only a few cases of immunoglobulin E (IgE)-mediated coconut allergies have been described in the literature. Due to a growing consumption of coconut-containing foods in occidental countries, the number of coconut allergies may also increase. As there is no causative immunotherapy in clinical routine, appropriate food labelling is particularly important, also with regard to cross-contamination, to prevent serious health consequences. The purpose of this study was to develop a DNA-based detection method for coconut (Cocos nucifera). Initially, three sets of coconut-specific primers were designed and tested. A TaqMan™ probe was then developed to identify and quantify coconut by real-time PCR assay. With 27 other plant and animal species, the specificity of the primer/probe system was tested and cross reactivity was excluded. In a dilution series, a limit of detection of 1 pg/µL was determined. Thus, the developed real-time PCR assay is a suitable method to detect coconut in food.

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