Detection of foodborne pathogens by qPCR: A practical approach for food industry applications

Abstract

Microbiological analysis of food is an integrated part of microbial safety management in the food chain. Monitoring and controlling foodborne pathogens are traditionally carried out by conventional microbiological methods based on culture-dependent approaches in control laboratories and private companies. However, polymerase chain reaction (PCR) has revolutionized microbiological analysis allowing detection of pathogenic microorganisms in food, without the necessity of classical isolation and identification. However, at present, PCR and quantitative polymerase chain reaction (qPCR) are essential analytical tools for researchers working in the field of foodborne pathogens. This manuscript reviews recently described qPCR methods applied for foodborne bacteria detection, serving as economical, safe, and reliable alternatives for application in the food industry and control laboratories. Multiplex qPCR, which allows the simultaneous detection of more than one pathogen in one single reaction, saving considerable effort, time, and money, is emphasized in the article.

Investigation and characterization of Shiga toxin‐producing Escherichia coli present in mussels from harvesting areas in Galician southern Rias (NW Spain)

“…Real‐time PCR is recognized as a highly specific and sensitive technique that can be completed in 1 hr after enrichment. Its potential for automation also makes it suitable for the screening of large numbers of food samples (Chapela, Garrido‐Maestu, & Cabado, ; Garrido‐Maestu, Chapela, Peñaranda, & Cabado, ). A multitude of both, real‐time and conventional, PCR assays have been described and evaluated for the detection of stx 1 and stx 2 genes in E. coli (Belanger, Boissinot, Menard, Picard, & Bergeron, ; Bischoff, Lüthy, Altwegg, & Baggi, ; Nielsen & Andersen, ; Paton & Paton, ; Wang, Clark, & Rodgers, ; Ziebell, Read, Johnson, & Gyles, ).…”

Multiplex Detection of Salmonella spp., E. coli O157 and L. monocytogenes by qPCR Melt Curve Analysis in Spiked Infant Formula

“…Fast and reliable analytical methods are needed by the industry, and control laboratories, to avoid potential illness and deaths. The development of molecular techniques based in DNA analysis, such PCR and particularly real-time PCR (qPCR), allow to reduce the time of analysis, decreasing hand-on steps allowing to handle several samples at the same time and detect different pathogens in a single analysis, being an advantage to reduce cost of reagents and labor needed [ 6 ].…”

Detection and Quantification of <i>Listeria</i><i> </i><i>m</i><i>onocytogenes</i> in Ready-to-eat Vegetables, Frozen Vegetables and Sprouts Examined by Culture Methods and Real-time PCR

“…The main advantages of qPCR include the ability of detecting and quantifying more pathogens (also viruses and protozoa) isolated from a single sample, with the possibility of the application of a multiplex format within a single qPCR reaction [2]. Many qPCR systems for the detection of foodborne pathogens are currently commercially available [2].…”

“…According to international law, unsafe food should not be placed on the market and to meet this requirement, microbiological testing must be performed on raw materials and finished products, as well as during the manufacturing process.Due to the short shelf life of raw vegetables, fast and automated detection systems for pathogens are required. This has led to a more widespread incorporation of real-time PCR (alternatively denoted as quantitative PCR -qPCR) methods in the food industry [2]. Further advantages of qPCR methods include the possibility of identifying and quantifying more pathogens simultaneously, and the detection of specific genes linked to strain virulence or resistance to antimicrobial agents.…”