Molecular methods for the detection and characterization of foodborne pathogens

Abstract

The surveillance of foodborne pathogens in food industries has shown the urgent need for rapid and dependable methods to detect and characterize the organisms in food and environments of clinical and epidemiologic importance. Recent studies on rapid methods in microbiology have been focused on biochemical characterization, immunoassays, and molecular methods. Many molecular methods have been developed and applied to the detection and characterization of foodborne pathogens in laboratories and food industries. They can be mainly divided into DNA banding pattern-based tests and DNA sequence-based tests. The former includes nucleic acid hybridization, polymerase chain reaction (PCR), amplified restriction length polymorphism, and randomly amplified polymorphic DNA, etc. Most of these methods in commercial applications are based on PCR or hybridization techniques. The principle, characteristics, and application of molecular methods for the detection and characterization of foodborne pathogens were reviewed in this article.

Evaluation of a multiplex selective enrichment broth SEL for simultaneous detection of injured Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes

“…For the truth that many foods are common carriers of Salmonella spp., E. coli O157:H7 and L. monocytogenes , traditional pathogen detection has burdened the industry and regulatory agencies, for the testing of foods that have a high risk of contamination with these pathogens (Nugen and Baeumner, 2008). Current research trends emphasize the development of multipathogen detection platforms in a single-assay format (Shi et al , 2010). The multipathogen detection approach is attractive and economically favorable since it can reduce labour requirement for handling a large number of samples, as well as reducing the overall cost of testing per pathogen.…”

Molecular techniques for detecting and typing of bacteria, advantages and application to foodborne pathogens isolated from ducks

“…Thus, in multiplex PCR more than one target sequences are amplified in a reaction to produce amplicons of varying sizes specific for different DNA sequences. Although multiplex PCR reduces cost, limits volume of samples and allows for the rapid detection of multiple bacteria species, strains and so on, primer design is critical in the development of multiplex PCR (Shi et al 2010). All primers need to have close annealing temperature, the amplicons must be markedly different in sizes and multiple primers may interfere with each other during the amplification process (Elnifro et al 2000; Shi et al 2010).…”

“…Although multiplex PCR reduces cost, limits volume of samples and allows for the rapid detection of multiple bacteria species, strains and so on, primer design is critical in the development of multiplex PCR (Shi et al 2010). All primers need to have close annealing temperature, the amplicons must be markedly different in sizes and multiple primers may interfere with each other during the amplification process (Elnifro et al 2000; Shi et al 2010). Boonmar et al (2007) compared the detection of Campylobacter species in duck meat and intestines in Nakhon Pathom Province, Thailand using the standard culture method (SCM) and multiplex PCR.…”

“…Real-time PCR is a polymerase chain reaction process in which the target DNA is amplified and quantified simultaneously within a reaction. Real-time PCR employs specific primer set, one or two probes and/or fluorescent dye to improve detection signals (Rensen et al 2006; Dhanasekaran et al 2010; Shi et al 2010). In real-time PCR, the amplified DNA is detected in real time as the reaction progresses instead of at the reaction end.…”

“…Real-time PCR shortens detection time compared to standard PCR and can determine the absolute or relative number of bacteria in various samples (Heid et al 1996; Shi et al 2010). Furthermore, there is no post-PCR processing of products, leads to high throughput and reduces the risk of amplicon contamination by laboratory environments (Heid et al 1996; Wong and Medrano 2005; Shi et al 2010). However, equipment and reagent costs are high for real-time PCR (Wong and Medrano 2005).…”