A method for detection of one or more microorganisms expressing one or more virulence factors comprising: a) contacting a sample suspected of containing one or more microorganisms expressing the one or more virulence factors with at least two sets of oligonucleotide primers specific to hybridize to target nucleic acids specific to the one or more virulence factors; b) amplifying at least one target nucleic acid sequence specific to the one or more virulence factors by a multiplex amplification method to obtain one or more amplified virulence factor specific nucleic acids; c) detecting the one or more amplified virulence factor specific nucleic acids or fragments or complements thereof; and d) identifying the amplified virulence factor specific nucleic acids, wherein detecting the one or more amplified virulence factor specific nucleic acids or fragments or complements thereof is indicative of the presence of a microorganism in the sample expressing the one or more virulence factor, wherein at least two sets of the oligonucleotide primers specific to the one or more virulence factors comprise at least a forward primer and at least a reverse primer operable to hybridize to a shiga toxin (stx) specific target nucleic acid and at least a forward primer and at least a reverse primer operable to hybridize to an eae specific target nucleic acid, wherein the oligonucleotide primers specific to hybridize to a stx specific target nucleic acid comprises one or more primer sets selected from a first primer set having SEQ ID NO: 1 and SEQ ID NO: 2; a second primer set having SEQ ID NO: 4 and SEQ ID NO: 5; a third primer set having SEQ ID NO: 6 and SEQ ID NO: 7; or a fourth primer set having SEQ ID NO: 8 and SEQ ID NO: 9 and the oligonucleotide primers specific to hybridize to an eae specific target nucleic acid comprise one or more primer sets selected from a primer set having SEQ ID NO: 11 and SEQ ID NO: 12 or a primer set having SEQ ID NO: 11 and SEQ ID NO: 13. a) contacting a sample suspected of containing one or more microorganisms expressing the one or more virulence factors with at least two sets of oligonucleotide primers specific to hybridize to target nucleic acids specific to the one or more virulence factors; b) amplifying at least one target nucleic acid sequence specific to the one or more virulence factors by a multiplex amplification method to obtain one or more amplified virulence factor specific nucleic acids; c) detecting the one or more amplified virulence factor specific nucleic acids or fragments or complements thereof; and d) identifying the amplified virulence factor specific nucleic acids, wherein detecting the one or more amplified virulence factor specific nucleic acids or fragments or complements thereof is indicative of the presence of a microorganism in the sample expressing the one or more virulence factor, wherein at least two sets of the oligonucleotide primers specific to the one or more virulence factors comprise at least a forward primer and at least a reverse primer operable to hybridize to a shiga toxin (stx) specific target nucleic acid and at least a forward primer and at least a reverse primer operable to hybridize to an eae specific target nucleic acid,