Effect of background microflora on the EMA-PCR. Four different viable or heat-killed C. jejuni strains (approximately 107 CFU/ml), (A) NTNC 11168, (B) C-484, (C) C-526, and (D) C-534, were analyzed by EMA-PCR either alone or in a background of approximately 108 CFU/ml each of viable Escherichia coli O157, Salmonella spp., and Listeria monocytogenes. The white and black columns show the EMA-PCR results for pure cultures and cultures with background microflora, respectively. The error bars represent standard deviations from three independent replicates.