Abstract: A method, diagnostic sequences and primers are provided that are useful in identifying the Listeria monocytogenes and Listeria spp. The method involves identifying a RAPD-amplified DNA fragment common to Listeria monocytogenes, then identifying the most conserved regions of that DNA fragment, and the preparing specific primers useful for detecting the presence of a marker within the fragment whereby that set of primers is then useful in the identification of all Listeria monocytogenes. Markers within the same fragment that are specific to the Listeria genus are also identified and are useful for the identification of all Listeria spp.

Abstract: A method for the identification of microorganisms is disclosed, comprising first isolating genomic DNA from the suspect microorganism. The isolated DNA has variable sequences interspersed between highly conserved rDNA sequences. The variable sequences are amplified. The amplification reaction is carried out in such manner as to either amplify the variable sequences interspersed between highly conserved rDNA sequences or to amplify arbitrary genomic regions in conjunction with the variable sequences. The resulting amplified DNA fragments are polymorphic with respect to both size and number in a manner which is specific to species, serotype and strain. The distribution of the polymorphic fragments is analyzed and compared to an established database to determine the species, serotype and strain of the suspect microorganism.

Abstract: A method, diagnostic sequences and primers are provided that are useful in the identification of the Escherichia coli 0157:H7 serotype. The method first involves the identification of a RAPD-amplified DNA fragment common to 0157:H7 Escherichia coli, the identification of the most conserved regions of that fragment, and the preparation of specific primers useful for detecting the presence of a marker within the fragment whereby that set of primers is then useful in the identification of all 0157:H7 Escherichia coli.

Abstract: A method is provided for the selection of diagnostic genetic markers fragments and useful in the identification of bacteria at the genus, species or serotype level. The method first involves the identification of a RAPD polymorphic DNA fragment common to a particular microbial group, the identification of the most conserved regions of that fragment, and the preparation of specific primers useful for detecting the presence of a marker within the fragment whereby that set of primers is then useful in the identification of all members of the chosen microbial group. Also provided is a specific diagnostic marker for Salmonella and primers directed thereto.

Abstract: A method is provided for the selection of diagnostic genetic markers fragments and useful in the identification of bacteria at the genus, species or serotype level. The method first involves the identification of a RAPD polymorphic DNA fragment common to a particular microbial group, the identification of the most conserved regions of that fragment, and the preparation of specific primers useful for detecting the presence of a marker within the fragment whereby that set of primers is then useful in the identification of all members of the chosen microbial group. Also provided is a specific diagnostic marker for Salmonella and primers directed thereto.