Probeliatm PCR system for rapid detection of Salmonella in milk powder and ricotta cheese

Abstract

The Probelia™Salmonella sp. PCR amplification and detection kits (Sanofi Diagnostics Pasteur, Marnes La Coquette, France) were evaluated for the rapid and specific detection of Salmonella agona artificially inoculated into skim milk powder and ricotta cheese. The Probelia™ results were compared with those obtained using the Australian Standard Method. Using a pure culture of Salm. agona, the detection limit of Probelia™ was between 8 and 79 cfu ml−1, equivalent to 0·2–2 cfu per PCR reaction. Detection of Salm. agona inoculated in skim milk powder (at 5–10 cfu g−1, stored at 5, 15 or 25 °C) and ricotta cheese (at 1–2, 10–20 and 100–200 cfu per 25 g) was effected by using non‐selective enrichment prior to the PCR determinations. For all of the 40 milk powder samples and 12 ricotta cheese samples, the Probelia™ results were consistent with those using the Australian Standard Method. Using Probelia™, Salmonella was detected to genus level in the dairy products within 24–28 h, whereas the cultural technique required 3–4 d for presumptive positive isolates and further time for confirmation.

Evaluation of real-time PCR vs automated ELISA and a conventional culture method using a semi-solid medium for detection of Salmonella

“…The Probelia TM PCR system has been the subject of comparative evaluations and has been shown to generate results that are consistent with the standard culture method (Fach et al. 1999; Wan et al. 2000).…”

“…The iQ-Check PCR is a qualitative homogenous real-time PCR assay using a specific fluorescent probe, a molecular beacon, which hybridizes to the amplified product during the PCR annealing step and allows the determination of PCR product in real-time whereas the Probelia TM PCR kit was based on DNA amplification by PCR followed by probe hybridization in a 96-well plate for colorimetric detection. The Probelia TM PCR system has been the subject of comparative evaluations and has been shown to generate results that are consistent with the standard culture method (Fach et al 1999;Wan et al 2000). Recent advancements in the PCR technology have enabled real-time detection of the PCR product eliminating the need of post-PCR processing (Cockerill and Smith 2002).…”

Multiplex PCR for the direct detection of Salmonella enterica from chicken, lamb and beef food products

“…Salmonellosis is a major economic problem for the food industry and a public health hazard in many countries (RUMEU et al 1997, WAN et al 2000, ZDRAGAS et al 2000. Salmonella enterica, the causative agents of Salmonellosis, represent one of the most common reasons of outbreaks of food poisoning worldwide, estimated 1.4 million annual cases in the United States (LACEY 1993, DAUM et al 2002.…”

Direct detection of Salmonella without pre-enrichment in milk, ice-cream and fruit juice by PCR against hilA gene

“…Owing to this problem Calvo et al adopted a better detection technique utilizing bipA gene and real-time PCR for the specific detection of 48 Salmonella strains (Calvó, Martínez-Planells, Pardos-Bosch, & Garcia-Gil, 2008). However, most of the PCR based techniques require a pre-enrichment and DNA extraction steps that lengthen the detection time (Calvó et al, 2008;Perelle et al, 2004;Wan et al, 2000). Moreover, the macromolecules in food inhibit the PCR (Perelle et al, 2004).…”