Real-time PCR with internal amplification control for the detection of Cronobacter spp. (Enterobacter sakazakii) in food samples

Food Control ◽  
2012 ◽  
Vol 25 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Xiang Wang ◽  
Changqing Zhu ◽  
Xinglian Xu ◽  
Guanghong Zhou
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Food Samples ◽  
Internal Amplification Control ◽  
Enterobacter Sakazakii

Development of Rapid Real-Time PCR and Most-Probable-Number Real-Time PCR Assays To Quantify Enterotoxigenic Strains of the Species in the Bacillus cereus Group

2007 ◽  
Vol 70 (12) ◽  
pp. 2774-2781 ◽  
Author(s):  
I-CHEN YANG ◽  
DANIEL YANG-CHIH SHIH ◽  
JAN-YI WANG ◽  
TZU-MING PAN
Keyword(s):  
Bacillus Cereus ◽  
Real Time ◽  
Real Time Pcr ◽  
Food Samples ◽  
Most Probable Number ◽  
Pcr Assay ◽  
Bacillus Cereus Group ◽  
Probable Number ◽  
Cooked Rice ◽  
Group Detection

Members of the Bacillus cereus group may produce diarrheal enterotoxins and could be potential hazards if they enter the food chain. Therefore, a method capable of detecting all the species in the B. cereus group rather than B. cereus alone is important. We selected nhe as the target and developed a real-time PCR assay to quantify enterotoxigenic strains of the B. cereus group. The real-time PCR assay was evaluated with 60 B. cereus group strains and 28 others. The assay was also used to construct calibration curves for different food matrices and feces. The assay has an excellent quantification capacity, as proved by its linearity (R2 > 0.993), wide dynamic quantification range (102 to 107 CFU/g for cooked rice and chicken, 103 to 107 CFU/ml for milk, and 104 to 107 CFU/g for feces), and adequate relative accuracy (85.5 to 101.1%). For the low-level contaminations, a most-probable-number real-time PCR assay was developed that could detect as low as 100 CFU/ml. Both assays were tested with real food samples and shown to be considerably appropriate for B. cereus group detection and quantification.

scholarly journals Sesame, Pistachio, and Macadamia Nut: Development and Validation of New Allergenic Systems for Fast Real-Time PCR Application

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1085
Author(s):  
Martina Torricelli ◽  
Elisa Pierboni ◽  
Cristina Rondini ◽  
Serena Altissimi ◽  
Naceur Haouet
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Food Processing ◽  
Annealing Temperature ◽  
Limit Of Detection ◽  
Food Samples ◽  
Support Tool ◽  
Macadamia Nut ◽  
Real Market ◽  
Development And Validation

Food allergy is a worldwide health problem that concerns infants to adults. The main health risk for sensitised individuals is due to the presence of traces of allergens as the result of an accidental contamination during food processing. The labelling of allergens such as sesame, pistachio, and macadamia nut on food products is mandatory according to Regulation (EU) N. 1169/2011; therefore, the development of suitable and specific analytical methodologies is advisable. The aim of this study was to perform a multi-allergen real-time PCR system that works well in fast mode at the same annealing temperature and with the same thermal profile. The real-time PCR was developed designing new, specific, and efficient primer and probe systems for the 2S albumingene for sesame and pistachio and for the vicilin precursorgene for macadamia nut. These systems were subjected to a robust intra-laboratory qualitative validation process prior to their application, by DNA extraction and fast real-time PCR, on some real market samples to reproduce a potential allergen contamination along the food chain. The developed system results were specific and robust, with a sensible limit of detection (0.005% for sesame; 0.004% for pistachio; 0.006% for macadamia nut). The performance and the reliability of the target systems were confirmed on commercial food samples. This molecular approach could be used as a screening or as a support tool, in association with the other widespread monitoring techniques (such as ELISA).

scholarly journals Detection and quantification of Campylobacter in foods: New analytic approaches to detect and quantify Campylobacter spp. in food samples

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Maria Francesca Peruzy ◽  
Yolande Thérèse Rose Proroga ◽  
Federico Capuano ◽  
Federica Corrado ◽  
Serena Santonicola ◽  
...  
Keyword(s):  
Real Time ◽  
Campylobacter Jejuni ◽  
Internal Control ◽  
Real Time Pcr ◽  
Quantitative Methods ◽  
Bacterial Load ◽  
Digital Pcr ◽  
Food Samples ◽  
Meat Samples ◽  
Campylobacter Spp

The aim of the present study was to develop rapid qualitative and quantitative methods based on the use of Real-Time PCR and Droplet Digital PCR (ddPCR), in order to have reliable techniques to detect and quantify Campylobacter spp. in food samples. The gene 16S-rRNA was used as specific target for Campylobacter spp. Real- Time PCR evaluation assay and a not competitive internal control was ushered in it. To investigate the selectivity of the method, 26 Campylobacter strains and 40 non-Campylobacter strains were tested and in order to verify the application of Real-Time PCR method, 5 pork meat samples were experimentally inoculated with a Campylobacter jejuni strain. Subsequently, dilutions with a bacterial load of Campylobacter jejuni within 10-106 CFU/mL were chosen for the optimization of the ddPCR assay. Lastly, a total of 54 naturally contaminated foods samples were analyzed through molecular (Real-Time PCR and ddPCR) and traditional methods. The Real-Time PCR protocol demonstrated to amplify only the Campylobacter spp. strains and when Campylobacter jejuni was experimentally inoculated in meat samples the pathogen was always detected. The ddPCRs assay allowed to quantify a level of contamination of 10 CFU/mL, but it was unable to quantify levels of 105 – 106 CFU/mL. Lastly, Campylobacter spp. was never detected in the 54 samples tested. In conclusion, the novel analytic approach proposed, based on an initial screening of the samples with Real-Time PCR and then on quantification of Campylobacter spp. with a ddPCR on those positive, represents a quick monitoring tool and, if used correctly, it would allow the implementation of food safety.

Real time PCR using TaqMan and SYBR Green for detection of Enterobacter sakazakii in infant formula

2006 ◽  
Vol 65 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Yin Liu ◽  
Xiaoning Cai ◽  
Xia Zhang ◽  
Qili Gao ◽  
Xiaochuan Yang ◽  
...  
Keyword(s):  
Real Time ◽  
Infant Formula ◽  
Real Time Pcr ◽  
Sybr Green ◽  
Enterobacter Sakazakii

Development of a real-time PCR assay with an internal amplification control for detection of Gram-negative histamine-producing bacteria in fish

2011 ◽  
Vol 28 (3) ◽  
pp. 356-363 ◽  
Author(s):  
Kristin Bjornsdottir-Butler ◽  
Jessica L. Jones ◽  
Ronald Benner ◽  
William Burkhardt
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Internal Amplification Control ◽  
Pcr Assay ◽  
Gram Negative

scholarly journals Rapid detection of Listeria monocytogenes in raw milk and soft cheese by a redox potential measurement based method combined with real-time PCR

2014 ◽  
Vol 62 (3) ◽  
pp. 304-316 ◽  
Author(s):  
Orsolya Erdősi ◽  
Katalin Szakmár ◽  
Olivér Reichart ◽  
Zsuzsanna Szili ◽  
Noémi László ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Redox Potential ◽  
Real Time ◽  
Real Time Pcr ◽  
Rapid Detection ◽  
Raw Milk ◽  
Food Samples ◽  
Potential Measurement ◽  
Effective Manner ◽  
Soft Cheese

The incidence of outbreaks of foodborne listeriosis has indicated the need for a reliable and rapid detection of the microbe in different foodstuffs. A method combining redox potential measurement and real-time polymerase chain reaction (PCR) was developed to detectListeria monocytogenesin artificially contaminated raw milk and soft cheese. Food samples of 25 g or 25 ml were homogenised in 225 ml of Listeria Enrichment Broth (LEB) with Oxford supplement, and the redox potential measurement technique was applied. ForListeriaspecies the measuring time was maximum 34 h. The absence ofL. monocytogenescould reliably be proven by the redox potential measurement method, butListeria innocuaandBacillus subtiliscould not be differentiated fromL. monocytogeneson the basis of the redox curves. The presence ofL. monocytogeneshad to be confirmed by real-time PCR. The combination of these two methods proved to detect < 10 cfu/g ofL. monocytogenesin a cost- and time-effective manner. This method can potentially be used as an alternative to the standard nutrient method for the rapid detection ofL. monocytogenesin food.

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