Salmonella spp. in poultry carcass: evaluation of sample preparation methods and effect of storage under refrigeration on pathogen recovery

Abstract

The aim of the present study was to evaluate the use of different analytical units and the influence of storage under refrigeration on the detection of Salmonella sp. in naturally contaminated poultry carcasses. One hundred and thirty samples were collected during the production process soon after chilling (postchiller phase). Fifty-five samples were analyzed in up to 2 h after collection and 65 samples were analyzed after 72 h of storage. Pathogen screening was based on three different analytical units and a comparison was made between them. Carcasses were initially rinsed with 400 mL of diluent, and three different analytical units were incubated: total rinsing volume (TRV), a single 30 mL aliquot of the rinsing volume, and 25 g of skin from different areas of the carcass. Of all samples analyzed, 60% were positive for Salmonella sp. From the samples collected at the post-chiller phase, 57% were positive for the pathogen and 52.31% of these were detected by TRV; a better statistical performance (P<0.05) when compared to the other analytical units. Of the refrigerated samples, 63% were contaminated, but there were no significant differences between analytical units (P>0.05). There were no significant differences between the number of positive samples from the post-chiller phase and after 72 h of refrigeration. It was also seen that the use of different analytical units (one for the post-chiller phase and another for the refrigerated samples) in samples coming from the same production lot may give different results.