This is particularly important

for samples containing low Listeria spp. numbers. Indeed, Listeria spp. grow slower than Enterobacteriaceae and its growth could be inhibited by the beef carcass co-resident microflora, and by Salmonella spp. in case of double contamination and the pre-enrichment in BPW instead of Half-Fraser is less optimal for Listeria spp. growth. However, these results demonstrated that BPW is efficient enough for Listeria detection as low as 4–16 cfu/swab with an overnight storage of the swab samples at fridge temperature. From these results, the positive and negative agreements (PA and NA), the positive and negative deviations (PD and ND) were assessed. For both targets, the PA and the NA result were 12 and 8 respectively while the ND and PD were 0. These values allowed the calculation of a 100% relative sensitivity (SE), 100% relative specificity Akt inhibitor (SP) and 100% relative accuracy (AC) and a Cohen’s kappa index of 1.00 of the results obtained with the complete CoSYPS Path Food workflow compared with the results obtained with the ISO methods (Table 2). These values demonstrated that the complete CoSYPS Path Food workflow is as efficient as the reference methods in detecting Salmonella spp. and L. monocytogenes in beef carcass swab samples. click here To perform the ISO reference methods, as well as the complete CoSYPS Path Food

workflow, classical L2 laboratory microbiological equipments are required. In addition, the complete CoSYPS Path Food workflow required qPCR well-trained personnel operating a properly maintained qPCR apparatus. The ISO 11290-1:1996 and ISO

6579:2002 comprise a pre-enrichment step, a selective enrichment step and isolation on selective plates (Fig. 1). These different steps need four and five days for Salmonella spp. and L. monocytogenes detection, respectively, since each culture step requires an 18 to 24 h of incubation (48 h for Fraser selective enrichment). If no typical colonies are observed on selective plates, the sample is concluded as containing no Salmonella spp. or L. monocytogenes all and the analysis is stopped. If typical colonies are observed on the selective plates, it is a presumptive positive result, and further biochemical confirmations are performed, which takes an additional day ( Fig. 1). The complete CoSYPS Path Food workflow comprises a pre-enrichment step, followed by a DNA extraction and a CoSYPS detection system (qPCR analysis). These steps can be completed within two days (including an overnight enrichment) as DNA extraction and CoSYPS analysis are easily performed within a single day. Indeed, DNA extraction requires maximum 3 h and the CoSYPS analysis needs around 4 h (preparation, running and result interpretation). If the CoSYPS analysis result is negative, the sample is concluded as containing neither Salmonella spp. nor Listeria spp. and the analysis is stopped.