• Chromogenic Listeria Agar Meets Iso Recommendations

Laboratory Products

Chromogenic Listeria Agar Meets Iso Recommendations

Nov 06 2006

The recently launched Oxoid Chromogenic Listeria Agar (OCLA), for the isolation, enumeration and presumptive identification of Listeria spp. and Listeria monocytogenes from food, conforms to the formulation described by Ottaviani and Agosti in ISO 11290 parts 1 & 2:1997.

The selective chromogenic medium, comprised of OCLA Base (ISO) [CM1084] and Listeria Selective Supplement (ISO) [SR0226E], detects the ?-glucosidase activity common to all Listeria species resulting in distinct blue colonies. The addition of phosphatidylinositol at 2g/L, as recommended in the ISO formulation, detects phosphatidylinositol phospholipase C (PIPLC) produced by pathogenic Listeria species. Alternatively, the addition of Oxoid Chromogenic Listeria Differential Supplement [SR0228E] detects phosphatidycholine phospholipase C (PCPLC). Either supplementation results in a clearly visible, opaque white halo around pathogenic Listeria colonies.

Both PIPLC and PCPLC are associated with the virulence of Listeria, but detection of either enzyme is sufficient for the identification of pathogenicity. Listeria monocytogenes is the most common pathogenic Listeria species, but some strains of L. ivanovii may also possess these enzymes. Pathogenic L. ivanovii will also produce blue colony halos on OCLA (ISO).

Digital Edition

MAC Guide 2023/24

December 2023

Buyers Guide - Major producers of analytical equipment who wish to introduce and sell their products to buyers in science and industry - Over 1,000 products and services that these companys man...

View all digital editions


Instrumentation Live

Jan 17 2024 Birmingham, UK

Smart Factory Expo 2023

Jan 24 2024 Tokyo, Japan

Arab Health

Jan 29 2024 Dubai, UAE

Nano Tech 2024

Jan 31 2024 Tokyo, Japan

SLAS 2024

Feb 03 2024 Boston, MA, USA

View all events