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Aims: To compare procedures for recovering template DNA from ground beef or chicken for polymerase chain reaction (PCR)‐based detection of Salmonella. Methods and Results: The primer set of ST11 and ST15 was utilized to amplify a 429‐bp product from Salmonella serotype Typhimurium. Boiling and three commercial kits were evaluated for extracting DNA from pure suspensions and artificially contaminated ground beef and chicken. The detection sensitivity of the PCR assay for pure cultures was independent of the template preparation method (P=0·946). Boiling and GeneReleaser™ failed to detect Salm. Typhimurium at 4 × 106 cfu g−1 in ground chicken. PrepMan™ Ultra and the high pure PCR template preparation kit facilitated reliable and sensitive detection of Salm. Typhimurium in two types of food. The sensitivities were approx. 4 × 103 cfu g−1. When spiked samples were enriched in peptone water for 6 h, an initial inoculum of 1 cfu g−1 was detectable. Conclusions: Four template DNA preparation methods differed in performance with respect to the type of samples tested. Significance and Impact of the Study: Template DNA for the PCR detection of pathogenic bacteria, such as Salmonella in meat and poultry, could be effectively obtained using a simple rapid method such as the commercially available PrepMan™ Ultra kit.

An image analysis system was developed and evaluated as a method for rapid detection of Salmonella typhimurium in pure culture and in chicken washes. A direct immunomagnetic separation and immunofluorescent staining technique was developed to capture and identify target cells. Digital images were acquired and segmented into background and bacteria. Bacteria were enumerated using a custom designed image analysis sofhuare. The image analyses results were compared with manual enumeration. A correlation coeflcient of 0.78 was established between manual and image analysis counts. In additon. the difference between the manual and the image analysis bacterial counts in individual images was low. Image analysis took an average of 15 s to analyze an image. m e results indicate that the proposed system has the potential to be used as a rapid screening procedure for bacterial detection in the food industry.3Correspondence to: Nmesh Singh,

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