Polymerase Chain Reaction for the Rapid Detection and Serovar Identification of Salmonella in Food and Feeding Stuff

Abstract

The polymerase chain reaction (PCR) is one of the most important rapid methods for the sensitive and specific detection of pathogenic and spoilage microorganisms. The method is increasingly applied in surveillance and monitoring programs to detect pathogens, especially for ensuring the safety and quality of food. The food-borne pathogen Salmonella together with Campylobacter is the most predominant bacterial pathogen in Europe, causing approximately 160,000 confirmed human cases per year. During the last two decades, the importance of Salmonella for food safety triggered the development of dozens of PCR-based detection methods. They promise significant advantages compared to the traditional culture-based methods with respect to speed, easiness, reliability, sensitivity, cost effectiveness, and automation. However, many of them are not applicable because of lacking validation procedures. Meanwhile, PCR has internationally been standardized and guidelines as well as standards for the validation of alternative methods, such as PCR, were established. This review will give an overview of the historical development of PCR-based methods for the detection of Salmonella including validation aspects and summarizes the state-of-the-art for the detection of Salmonella in food and feeding stuff by realtime PCR. Furthermore, current multiplex PCR-based serovar-specific identification methods will be reviewed.

Development of a multiplex real-time PCR method for simultaneous detection of Salmonella enterica, Shigella flexneri and Listeria monocytogenes in processed food samples

“…This genus is included in the Enterobacteriaceae family [4]. Currently, two species are recognized, Salmonella enterica, subdivided into six subspecies, and Salmonella bongori [5]. Salmonella strains can cause serious infection mainly through food poisoning, and salmonellosis, a zoonotic disease of considerable importance [6].…”

“…This methodology is increasingly applied in surveillance and monitoring programs to detect pathogens, especially for ensuring the safety and quality of food and to identify weak points during production [22]. In the early 1990s, the "second" generation of PCR technologies was introduced by the use of Xuorescent ds-DNA dyes or DNA probes, where PCR and detection occur in a one-step, closed-tube procedure reducing the risk of contamination leading to false-positive results [5]. Several methods have been developed for single real-time PCR detection of Shigella spp.…”

Evaluation of the BAX® system for the detection of Salmonella spp. in naturally contaminated chicken meat

“…in foods. Many of these alternative methods have been validated by international organizations, but most of these validations are carried out on artificially contaminated samples, and these methods might produce different results when naturally contaminated foods are tested (MALORNY et al, 2009).…”

Detection and Identification of Salmonella enterica, Escherichia coli, and Shigella spp. via PCR-Electrospray Ionization Mass Spectrometry: Isolate Testing and Analysis of Food Samples

“…Other samples were unspiked, and the samples were all blinded. The spiking levels were chosen to be consistent with other evaluations of rapid detection methods (12,32,34). After PCR-MS results were obtained and interpreted, the identities of the spiked samples were revealed.…”