A non-isotopic DNA hybridisation assay for the identification of Staphylococcus aureus isolated from foods

A digoxygenin-labelled total genomic DNA probe was used to identify Staphylococcus aureus. Isolation and identification of organisms was possible in less than 4 days. Identification alone could be completed in less than 2 days, compared with over 5 days for identification of isolates by multipoint inoculation. The probe showed excellent discrimination of S. aureus from other staphylococci and from a wide range of bacteria commonly associated with milk and meat. The effectiveness of this probe was tested against cultural isolation of staphylococci in milk using Baird-Parker agar followed by identification using multipoint inoculation and API Staph. The probe gave comparable results to the conventional methods and, for large sample numbers, offered lower cost and greater ease of use.