CRITERION™ Universal Preenrichment Broth

Cat. no. C7220 CRITERION™ Universal Preenrichment Broth 76.1gm
Cat. no. C7221 CRITERION™ Universal Preenrichment Broth 500gm
Cat. no. C7222 CRITERION™ Universal Preenrichment Broth 2kg
Cat. no. C7223 CRITERION™ Universal Preenrichment Broth 10kg

INTENDED USE

Hardy Diagnostics CRITERION™ Universal Preenrichment Broth is recommended for recovering sublethally injured Salmonella and Listeria from food products.

SUMMARY

Traditional methods for recovering Salmonella spp. and Listeria spp. from food products require separate preenrichment media for each microorganism. (1,2) Some broth media recommended for preenrichment contain antibiotic inhibitors or have insufficient buffering capacity which hinder recovery of sublethally injured cells. (3-5)

Bailey and Cox formulated Universal Preenrichment Broth to permit simultaneous resuscitation of sublethally injured Salmonella and Listeria . The formulation provides sufficient buffering capacity to prevent rapid decreases in pH, and allows for repair of injured cells that might be sensitive to low pH or inhibitory substances. According to the FDA's Bacteriological Analytical Manual (BAM), Universal Preenrichment Broth is used as preenrichment of Salmonella spp. when testing orange and apple juice, cider, cantaloupes, tomatoes, and mamey pulp. (2)

CRITERION™ Universal Preenrichment Broth follows the BAM formulation and contains peptones as sources of carbon, nitrogen, vitamins and minerals. Sodium and potassium phosphates buffer the medium while sodium chloride maintains osmotic balance. Magnesium sulfate and ferric ammonium citrate provide essential ions. Dextrose is an energy source and sodium pyruvate helps to stimulate the metabolism of stressed organisms.

FORMULA*

Gram weight per liter: 38.05gm/L
Monopotassium Phosphate 15.0gm
Disodium Phosphate 7.0gm
Pancreatic Digest of Casein 5.0gm
Proteose Peptone 5.0gm
Sodium Chloride 5.0gm
Dextrose 0.5gm
Magnesium Sulfate 0.25gm
Sodium Pyruvate 0.2gm
Ferric Ammonium Citrate 0.1gm

Final pH 6.3 +/- 0.2 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.

STORAGE AND SHELF LIFE

Store the sealed bottle(s) containing dehydrated culture medium at 2-30ºC. Dehydrated culture medium is very hygroscopic. Keep lid tightly sealed. Protect dehydrated culture media from moisture and light. The dehydrated culture media should be discarded if it is not free-flowing or if the color has changed from its original light beige

Store the prepared culture media at 2-8ºC.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 38.05gm of the dehydrated culture media in one liter of distilled or deionized water. Stir to mix thoroughly.

2. Heat as necessary to dissolve completely and dispense desired volume into clean containers.

3. Sterilize in the autoclave at 121ºC. for 15 minutes.

4. Cool containers and cap tightly.

PROCEDURE

Refer to the appropriate references for preenrichment procedures for Salmonella and Listeria . (1,2)

INTERPRETATION OF RESULTS

Refer to the appropriate procedure for expected results. (1,2)

Salmonella and Listeria demonstrate good growth and recovery following preenrichment in this broth.

LIMITATIONS

Due to nutritional variation, some strains may be encountered that grow poorly or fail to grow.

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as autoclaves, incinerators, and incubators, etc., are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Listeria monocytogenes
ATCC ® 7644
J 18-24hr 35°C Aerobic Growth and typical colony morphology upon subculture to Blood Agar
Salmonella enterica
ATCC ® 14028
J 18-24hr 35°C Aerobic Growth and typical colony morphology upon subculture to Blood Agar

User Quality Control

Physical Appearance

CRITERION™ Universal Preenrichment Broth powder should appear homogeneous, free-flowing, and light beige in color. The prepared medium should should appear slightly opalescent to opalescent, and light to medium amber in color. The broth may have a precipitate but no debris.

REFERENCES

1. APHA Technical Committee on Microbiological Methods for Foods. Compendium of Methods for the Microbiological Examination of Foods, APHA, Washington, D.C.

2. U.S. Food and Drug Administration. Bacteriological Analytical Manual. AOAC, Arlington, VA. www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm2006949.htm

3. Bailey, J.S., and N.A. Cox. 1992. Universal preenrichment broth for the simultaneous detection of Salmonella and Listeria in foods. J. Food Protect. ; 55:256-259.

4. Bailey, J.S., D.L. Fletcher, and N.A. Cox. 1990. Efficacy of enrichment media for recovery of heat-injured Listeria monocytogenes . J. Food Prot. ; 47:299-302.

5. Juven, B.J., N.A. Cox, J.S. Bailey, J.E. Thomson, O.W. Charles, and J.V. Shutze. 1984. Recovery of Salmonella from artificially contaminated poultry feed in non-selective and selective broth media. J. Food Prot. ; 47:299-302.


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