Abstract: The present invention provides nucleic acid products and corresponding methods for screening a biological sample for the presence of an E. coli strain causing an infection.

Abstract: This invention provides 163 genes that are unique to the L. monocytogenes serovar 4b strain, CLIP80459, compared with L. monocytogenes EGDe strain. These genes are the basis for isolated nucleic acids, hybridization supports, and kits comprising a nucleotide sequence that is unique to a serovar 4b strain of L. monocytogenes. The invention also provides methods for identifying a L. monocytogenes in a sample, methods for identifying the lineage of a L. monocytogenes in a sample, and methods for sub-lineage typing of a L. monocytogenes in a sample. The invention also provides hybridization supports comprising a L. monocytogenes lineage-specific nucleic acid sequence, hybridization supports comprising a L. monocytogenes sub-lineage-specific nucleic acid sequence combination, and kits comprising a nucleic acid or hybridization support of the invention. Additionally, the invention provides specific macroarrays, methods, and kits for use in serotyping L. monocytogenes.