Listeria sp. Identification Test

Listeria sp.

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Morphology: Rods

Gram: Positive

Catalase: Positive

Respiratory system: Facultative anaerobe 

Motility: Peritrichous

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Tests to identify the genus

• Hemolysis test - Sheep blood agar
• CAMP factor - Sheep blood agar
• Mixed acid or butane-diol fermentation - Clark and Lubs medium
• Sugar fermentation: xylose, mannitol, rhamnose
• Nitrate reductase

Culture

PALCAM agar

Listeria sp. on PALCAM agar

On BD PALCAM Listeria Agar, colonies of Listeria appear gray-green with a black halo. Confirmation of the presence of Listeria is made following subculture onto appropriate media and biochemical/serological identification. Colonies of mannitol-fermenting organisms such as staphylococci, which may grow on this medium, appear yellow with a yellow halo.

Refererence: BD™ [Link]

ALOA™ agar

Listeria monocytogenes on ALOA™

Please, feel free to comment if there is any mistake.