Due to the severity of infection which E. coli O157:H7 causes and an infectious dose which may be as low as 10 organisms, it has emerged as an important foodborne pathogen of considerable public health concern, so it\'s enumeration in foods is critical. Number of 101 to 105 ml -1 of bacteria were inoculated in sterilized milk. Modified MPN dilutions from inoculated milk sample (10, 1, 0.1, 0.01, 0.001 ml) with three replicates per dilution were prepared, using modified m-TSB (containing 20 mg L-1 novobiocin) Different background microorganisms including gram positive and gram negative bacteria were also inoculated. Enumeration was performed by DNA extraction from tubes showing turbidity and performing multiplex-PCR using primers specific for O157 and H7 antigens gene.This MPN-PCR proved to be a rapid and reliable method for enumerating Escherichia coli O157:H7 in milk, including low contaminated samples and may facilitate the enumeration of Escherichia coli O157:H7 for routine analyses in milk without excessive work.

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