A RAPID METHOD FOR SCREENING FOR SALMONELLA-TYPHIMURIUM IN A CHICKEN CECAL MICROBIAL CONSORTIUM USING GENE AMPLIFICATION

A rapid sample processing method has been developed to detect low numb ers of Salmonella typhimurium in a chicken cecal microbial consortium. Using phoP-specific primers under stringent amplification conditions and gene probe analysis, fewer than 100 colony-forming units (CFUs) we re detectable when pure cultures were employed. When the polymerase ch ain reaction assay was run on cecal contents from birds infected with S. typhimurium, only positive cecal samples containing as few as 700 C FUs reacted to the assay, and the negative bird samples reacted only w hen the samples were spiked with S. typhimurium cells. The method empl oyed for sample processing is simple and provides a sensitive means of detecting S. typhimurium-specific sequences in trace amounts in the p resence of mixed chicken cecal microbial populations.