Comparison of DNA-extraction methods and Selective Enrichment broths on the detection of Salmonella Typhimurium in swine feces by polymerase chain reaction (PCR)

the aim of this study was to compare different dna-extraction methods and selective enrichment broths for their effectiveness to detect salmonella typhimurium in artificially inoculated swine feces samples (100 cfu/g) by polymerase chain reaction. after enrichment in rappaport-vassiliadis, selenite cystine or müller-kauffmann tetrathionate, aliquots were used for dna extraction by three different methods: boiling-centrifugation, phenol-chloroform and salting-out. aliquots of extracted dna were then used as template in pcr. the selective enrichment broths had no effect on the efficiency of pcr when boiling-centrifugation and salting-out were used. on the other hand, phenol-chloroform was superior (p<0.05) when combined to rappaport-vassiliadis. considering cost and efficiency parameters, we encourage the use of müller-kauffmann tetrathionate broth in combination with boiling-centrifugation dna-extraction procedure.