Lab M's new Baird-Parker Medium (ISO) is the latest addition to the company's range of microbiological culture media developed to meet specific ISO requirements in the food industry.

This improved version of Baird-Parker Medium, for the isolation of coagulase-positive staphylococci including Staphylococcus aureus from food and animal feedstuffs, is formulated according to ISO 6888-1:1999 and is in compliance with ISO 6888-2:2003. It is tested in accordance with ISO/TS 11133-2:2003(E).

Through the selection of only the finest raw materials, Lab M's Egg Yolk Tellurite has been improved to complement this Baird-Parker formulation. As with Lab M's traditional Baird-Parker medium, the new formulation can be used with either Egg Yolk Tellurite or Rabbit Plasma Fibrinogen (RPF). The use of RPF produces enhanced reactions compared with previous Baird-Parker formulations.

When the medium is used with Egg Yolk Tellurite, presumptive S. aureus appear as black colonies demonstrating lecithinase activity as an opaque zone around the colony, encircled by a zone of clearing that is the result of lipase activity. Coagulase (RPF media) or latex agglutination tests are used for confirmation.

Where Rabbit Plasma Fibrinogen is used, typical S. aureus appear as black colonies surrounded by a zone of precipitation, indicating coagulase activity. This is the recognised gold standard method for the identification of S.aureus. RPF overcomes any issues with atypical colony forms and also means that further confirmatory tests are not necessary.