Evaluation of a Multiplex PCR assay for simultaneous identification of Salmonella sp., Salmonella Enteritidis and Salmonella Typhimurium from environmental swabs of poultry houses

A Multiplex PCR-based assay (m-PCR) with three sets of primers was develope d for the detection of all serotypes of Salmonella enterica and the identif ication of Salmonella Enteritidis and Salmonella Typhimurium. This method w as evaluated against a bacteriological method for the analysis of environme ntal swabs of poultry houses. Samples were preenriched in phosphate-buffere d peptone water for 24 h and subjected to three different protocols prior t o PCR: (i) an immunomagnetic separation using Dynabeads(TM) anti-Salmonella (Dynal); (ii) a DNA extraction procedure using the Instagene(TM) matrix; ( iii) an additional step of culture on an MSRV medium. With protocols 1 and 2, eight positive results were found by PCR and 20 with the bacteriological method. Protocol 3 combining MSRV and PCR gave similar results to those ob tained from bacteriological methods and allowed Salmonella detection within 2 days.