PALCAM LISTERIA AGAR

Technical Data #1116a / 98.04.22

Palcam Listeria Agar supplemented with antibiotics is used for the selective isolation of Listeria monocytogenes from foods. Esculin hydrolysed by the Listeria sp. strains give black colonies. Antibiotics and lithium chloride are the inhibitors of gram positve and gram negative bacteria. Phenol red is the indicator.

 

FORMULA
in grams per liter purified filtered water

 

Casein Peptone

10,0
Meat Peptone

5,0
Yeast Extract

3,0
Heart Peptone

3,0
Sodium Chloride

5,0
Corn Starch

1,0
Esculin

0,8
Ferric Ammonium Citrate

0,5
Lithium Chloride

15,0
Dextrose

0,5
D-Mannitol

10,0
Phenol Red

0,08
Agar

15,5
Supplement

 
Palcam Selective Enrichment

10 ml

pH 7,2 +/- 0,2 at 25º C

This approximate formula may be adjusted and/or enriched to obtain best results.


PRECAUTIONS
This medium is for IN VITRO diagnostic use only.


STORAGE
Store prepared media at 2-8º C protected from direct light and dehydrated powder, in a dry place in tightly-sealed containers at 2-25º C.


SIGN OF DETERIORATION
Media should not be used if the expiry date has passed. Prepared media should not be used if there are signs of contamination (shrinking, cracking, evaporation or discoloration). Do not use dehydrated media if it is caked.


DIRECTIONS
Suspend 69 g in 1000 ml of purified water. Heat with frequent agitation and boil for one minute. Sterilize at 121º C for 15 minutes. Cool to 45-50º C. Add 10 ml of Palcam Selctive Supplement (#8726). Mix thouroughly and dispense into Petri dishes.


PROCEDURE
Bring prepared medium at room temperature before inoculation.

  1. Directly, inoculate the specimen and streak for isolated colonies.
  2. Incubate at 35º C for 24-48 hours.


QUALITY CONTROL
Results after 24 hrs at 35ºC

 

Organisms

ATCC

Growth
Listeria monocytogenes

15313

+ black colonies
Staphylococcus aureus

25923

- or partial
Escherichia coli

25922

- or partial

LIMITATIONS OF METHOD
This is only a part of the identification. Others tests may be required.


REFERENCES

  1. Lennette, E.H., Ballows, A., Hausler, W.J.Jr., and Shadomy, H.J. Manual of Clinical Microbiology. 4th ed. 1985 Washington D.C.: American Society for Microbiology.
  2. Mac Faddin, Jean F. 1985 Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria. Vol. I, Baltimore, MD.: Williams & Wilkins.
  3. Van Netten, P., I. Perales, A. Van de Moosdijk, D.M. Curtis, D.A.A. Mossel 1989 Liquid and solid differentiation media for enumeration of L. monocytogenes and other Listeria spp. J. Food Microbiol. 8:299-316.


CATALOGUE NUMBERS 

Dehydrated media 500 g QB-39-3509
     
Palcam Supplement, 10x5 ml 10/pkg 8726
     
Prepared media    
Plates, 100x15 mm 10/pkg 1116