Listeria ID

Features:

• AOAC approved
• Inoculation is simple
• Identify from selective or non-selective media
• Final confirmation in 24 hours or less
• Unique haemolysis test included
• No additional testing needed

• No MacFarland standard
• No CAMP test
• No 24 hour blood plate
• No set-up
• No weak or confusing color changes

Easy to use:

• Select a single colony of the isolate to be identified
• Emulsify colony in the suspending medium provided
• Add 3- 4 drops (100µL) suspension to each well of the strip(s)
• Add 1 drop of haemolysin red blood cells to well 12 (shake vial)
• Incubate 18-24 hours at 35-37°C
• Read and Record results using software (purchased separately)

Species identified:

• L. monocytogenes
• L. innocua
• L. seeligeri
• L. ivanovii
• L. welshimeri
• L. grayi

The Listeria ID system employs 12 standardized microwell biochemical substrates, including an in-well haemolysin test. The substrates are based on classical methods and include: Esculin, Mannitol, Xylose, Arabitol, Ribose, Rhamnose, Trehalose, Tagatose, Glu-1-Phos, Methyl-D-Glucoside, Methyl-D-Mannoside and Hemolysis. The inoculation and incubation of the substrate in each microwell causes a simple color change reaction, yellow is a positive reaction, purple is a negative reaction; there is no guess work involved.

Haemolysin Reaction

For convenience, an in-well haemolysin test is also included, eliminating the need for additional tests such as CAMP. As the detection of the haemolytic activity is fundamental to the identification of Listeria species (in particular L. monocytogenes and L. ivanovii) and the interpretation of this reaction is sometimes difficult, Microgen Bioproducts has developed a highly sensitive, easily interpreted and stable microwell haemolysin test. The haemolysin test is simply performed by adding 1 drop of the specially stabilized sheep red blood cells (included with kit) to the last well (well 12) of the Microgen Listeria ID test panel. If the organism being identified produces haemolysin, the red blood cells will rapidly be lysed and the cellular contents released into the suspending medium. The contents of the well will appear as a homogeneous red/ brown solution. Alternatively, if the organism being identified does not produce haemolysin, the stabilized red blood cells will remain intact. These cells will settle to the bottom of the microwell forming a distinct red layer with a clear supernatant.

Procedure

Using Listeria ID is simple and requires no set-up. Select a single colony of the isolate to be identified. The colony can be taken from selective or non-selective media, we suggest using BBL^TM CHROMagar^TM Listeria for presumptive identification. Emulsify colony in the suspending medium provided. Add 3- 4 drops (100µL) suspension to each well of the strip(s). Add 1 drop of red blood cells (provided) to the haemolysin test (well 12). Incubate for 18-24 hours at 35^o – 37^oC. Read and record results using the software program (sold separately). For a complete explanation of procedure for use, please refer to the Instructions for Use, included with your kit.

• Well 1- Esculin

• Well 2- Mannitol

• Well 3- Xylose

• Well 4- Arabitol

• Well 5- Ribose

• Well 6- Rhamnose

• Well 7- Trehalose

• Well 8- Tagatose

• Well 9- Glu-1-Phos

• Well 10- Methyl-D-Glucoside

• Well 11- Methyl-D-Mannoside

• Well 12- Haemolysis