Support Technical Data FRASER FOR LISTERIA BROTH
Technical Data # 2591a / 2010.08.18
Fraser for Listeria broth is a selective medium used for cultivation of Listeria monocytogenes . Esculin hydrolysed by Listeria sp. products a dark brown complex with Ammonium ferric citrate. Nalidixic acid inhibits Gram negative microorganisms while Lithium Chloride inhibits Enterococcus.
FORMULA
in grams per litre purified filtered water
Casein Peptone ........................................10,0
Beef extract……………..................................5,0
Yeast extract...............................................5,0
Sodium Chloride ......................................20,0
Lithium Chloride.........................................3,0
Esculin........................................................1,0
Sodium Phosphate dibasic.........................9,6
Potassium Phosphate monobasic...............1,35
Ammonium ferric Citrate.............................0,5
Acriflavin ....................................................0,012
Nalidixic acid ..............................................0,02
pH 7,3 +/- 0,2 at 25º C
This approximate formula may be adjusted and/or enriched to obtain best results.
PRECAUTIONS
This medium is for laboratory use only.
STORAGE
Store prepared media at 2-8° C protected from direct light and dehydrated powder, in a dry place, in tightly-sealed containers at 2-25° 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 or deterioration (shrinking, cracking, evaporation or discoloration). Do not use dehydrated media if it is caked.
DIRECTIONS
Suspend 55.5 g of dehydrated media in 1000 ml of purified filtered water. Heat with frequent agitation and boil for one minute. Dispense into culture tubes or vial and sterilize at 121º C for 15 minutes. Precipitate may be observed but this is not interfered the performance.
PROCEDURE
Prior to inoculate, the prepared media should be brought to room temperature.
QUALITY CONTROL
Results after 48 hrs at 35ºC
Organisms ATCC Growth
Listeria monocytogenes 15313 +
Staphylococcus aureus 25923 - or partial
Escherichia coli 25922 - or partial
Enterococcus faecalis 29212 - or partial
LIMITATIONS OF METHOD
This medium is only a part of the identification. Other tests may be required.
REFERENCES
1) Fraser, J.A. and Sherber, W.H. 1988 Rapid Detectiobn of Listeria in Food and Environmental Samples by Esculin Hydrolysis. J. Food Prot. 51:762-765
2) Mac Faddin, Jean F., 1985 Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria. Vol.1. Baltimore, MD.: Williams & Wilkins.
3) Standard Methods for Examination of Water and Wastewater 1989 17th ed. APHA Washington D.C.
CATALOGUE NUMBERS
Deshydrated medium 500 g QB-39-1804
Prepared medium
Tubes 16x125 mm, 10 ml 10/pkg 2591
