Twelve-Hour PCR-Based Method for Detection of Salmonella spp. in Food

Abstract

A PCR-based method for the detection of Salmonella spp. in food was developed. The method, set up on typical salami from the Italian region of Marche, is sensitive and specific and shows excellent correlation with the conventional method of reference when naturally contaminated foods are analyzed. Moreover, it can be easily performed within a maximum of 12 h from food sampling, thus allowing prompt detection of Salmonella spp. in the food stocks analyzed.

Rapid, sequence-specific detection of unpurified PCR amplicons via a reusable, electrochemical sensor

“…For example, it has been shown that the early identification of bacterial pathogens can significantly reduce the breadth and severity of outbreaks of food-borne diseases (1), outbreaks that are responsible for Ϸ76 million illnesses, 325,000 hospitalizations, and 5,000 deaths per year in the United States alone (2). Current methods for the detection and identification of bacteria, however, are complex and slow; because the minimum infectious doses of food-borne pathogens such as Escherichia coli, Listeria monocytogenes, and Salmonella are very low (3,4), the detection of clinically relevant levels of contamination generally requires amplification of the infectious organism via laboratory culturing over the course of 1 to several days (5,6).…”

Occurrence of Listeria monocytogenes in Salami Manufactured in the Marche Region (Central Italy)

“…The occurrence of L. monocytogenes in these salami samples collected from the Marche Region is comparable to that previously reported for other Italian [7,22] and European [16] fermented sausages. Although the Ciauscolo salami is believed to be a product at high risk of contamination, as a consequence of the short ripening time, the generally high a w , and the rare use of additives and starter cultures [3,8,11,21], the statistical analysis of the data allow us to reject this hypothesis, as no statistically significant differences are seen here between this product and the other salami sampled. With respect to the previous Italian regulations, which showed no tolerance for L. monocytogenes in ready-to-eat meat products, all of the samples that were positive for the presence of this pathogen would have to be considered as not acceptable.…”

Detection of Salmonella in Food Samples by Culture and Polymerase Chain Reaction Methods

“…Other studies have also reported that the use of a PCR assays were more sensitive than the culture method for detecting Salmonella in food, especially in poultry, meat, and poultry related products [17][18][19][20][21]. In this study we used a method proposed by Ferretti et al [16] who applied a PCR method without Internal Amplification Control (IAC), and although similar studies have been published previously [17][18][19][20][21], but PCR could be improved by introduction of a general IAC to prevent the occurrence of false negative results and to control the effects of inhibiting agents on amplification efficiency [22,23].…”

“…Molecular screening methods have been also used to detect nucleic acids. In this study, we used a rapid and simpler method proposed by Ferretti et al [16] that relying on a 6-h nonselective enrichment in BPW followed by cell breaking and PCR to detect Salmonella spp. within a maximum of 12 hour from the receipt of food samples.…”