Hardy Diagnostics HUGO


Cat. no. U51 UVM Modified Listeria Enrichment Broth,
500ml Polycarbonate Bottle, 500ml
10 bottles/box
Cat. no. U153 UVM Modified Listeria Enrichment Broth,
500ml Polycarbonate Bottle, 225ml
10 bottles/box


Hardy Diagnostics UVM Modified Listeria Enrichment Broth is recommended for the rapid isolation of Listeria monocytogenes.

This product is not intended to be used for the diagnosis of human disease.


Listeria monocytogenes is a widespread problem in public health and food industries. Listeria monocytogenes was first described in 1926 by Murray, Webb and Swann, and can cause human illness and death, particularly in immunocompromised individuals and pregnant women.(1,2) The first reported food-borne outbreak of listeriosis was in 1985.(3) The principle route of transmission is via the consumption of foodstuffs contaminated with Listeria monocytogenes.(4)

This organism has been isolated from turkey frankfurters, coleslaw, pasteurized milk, Mexican-style cheese, pate, and pickled pork tongue.(5) Listeria monocytogenes is present in a wide range of unprocessed foods as well as in soil, sewage, silage, and river water.(6) Listeria species can grow over a pH range of 5.0-9.6 and survive in food products with pH levels outside of that range.(7)

UVM Modified Listeria Enrichment Broth is a modification of the formula described by Donnelly and Baigent.(9) It is used for selective enrichment of Listeria spp. from food and clinical specimens.

UVM Modified Listeria Enrichment Broth contains beef extract, yeast extract, pancreatic digest of casein, and peptic digest of animal tissue which provide nitrogen, vitamins and minerals. Sodium chloride is added to maintain osmotic balance and phosphate is added as a buffer. Nalidixic acid inhibits gram-negative organisms and acriflavine hydrochloride inhibits many gram-positive bacteria. Esculin is hydrolyzed by Listeria species.


Ingredients per liter of deionized water:*

Sodium Chloride 20.0gm
Disodium Phosphate 9.6gm
Pancreatic Digest of Casein 5.0gm
Peptic Digest of Animal Tissue 5.0gm
Beef Extract 5.0gm
Yeast Extract 5.0gm
Monopotassium Phosphate 1.35gm
Esculin 1.0gm
Nalidixic Acid 20.0mg
Acriflavine HCl 12.0mg

Final pH 7.2 +/- 0.2 at 25°C.

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


Storage: Upon receipt store at 2-30 degrees C. away from direct light. Media should not be used if there are any signs of deterioration (shrinking, cracking, or discoloration), contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.



1. Collect specimens or food samples in sterile containers or with sterile swabs and transport immediately to the laboratory following recommended guidelines.(7,10-12)

2. Clinical specimens obtained from non-sterile sites, foods and specimens obtained from the environment should be selectively enriched for Listeria species before being plated.(10)

3. Process each specimen using procedures appropriate for that specimen or sample.(7,10-12)

Test Procedure

The USDA method involves enrichment of the specimen in UVM Modified Listeria Broth (one part sample in nine parts broth) at 30 degrees C. After incubation, a portion of the enrichment mixture is added to an enrichment broth or plated onto the final isolation agar.(7,11) For further information when testing food samples or clinical specimens, refer to appropriate references.(7,10-12)


Refer to appropriate references and procedures for results.



Standard microbiological supplies and equipment such as loops, other culture media, swabs, applicator sticks, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Listeria monocytogenes**
ATCC® 19114
A 18-48hr 35°C Aerobic Growth
Staphylococcus aureus
ATCC® 29523
B 18-48hr 35°C Aerobic Partial to complete inhibition
Escherichia coli**
ATCC® 25922
B 18-48hr 35°C Aerobic Partial to complete inhibition
Enterococcus faecalis**
ATCC® 29212
B 18-48hr 35°C Aerobic Partial to complete inhibition

** Recommended QC strains for User Quality Control according to the CLSI document M22 when applicable.

User Quality Control


UVM Modified Listeria Enrichment Broth should appear clear, may have a slight precipitate, and light amber in color.


1. Murray, E.G.D., R.A. Webb, and M.B.R. Swann. 1926. A disease of rabbits characterized by large mononuclear leucocytosis caused by a hitherto undescribed bacillus Bacterium monocytogenes . J. Path. Bact. ; 29:407-0439.

2. Monk, J.D., R.S. Clavero, L.R. Beuchat, M.P. Doyle, and R.E. Brackett. 1994. Irradiation inactivation of Listeria monocytogenes and Staphylococcus aureus in low- and high-fat, frozen and refrigerated ground beef. J. Food Prot. ; 57:969-974.

3. Wehr, H.M. 1987. Listeria monocytogenes - a current dilemma special report. J. Assoc. Off. Anal. Chem. ; 70:769-772.

4. Bremer, P.J. and C.M. Osborne. 1995. Thermal-death times of Listeria monocytogenes in green shell mussels ( Perna canaliculus ) prepared for hot smoking. J. Food Prot. ; 58:604-608.

5. Grau, F.H. and P.B. Vanderlinde. 1992. Occurrence, numbers, and growth of Listeria monocytogenes on some vacuum-packaged processed meats. J. Food Prot. ; 55:4-7.

6. Patel, J.R., C.A. Hwang, L.R. Beuchat, M.P. Doyle, and R.E. Brackett. 1995. Comparison of oxygen scavengers for their ability to enhance resuscitation of heat-injured Listeria monocytogenes. J. Food Prot. ; 58:244-250.

7. Donnelly, C.W., R.E. Brackett, D. Doores, W.H. Lee, and J. Lovett. 1992. Compendium of Methods for the Microbiological Examination of Foods, 3rd ed. American Public Health Association , Washington, D.C.

8. Kramer, P.A. and D. Jones. 1969. Media selective for Listeria monocytogenes . J. Appl. Bacteriol. ; 32:381-394.

9. Donnelly, C.W. and G.J. Baigent. 1986. Method for flow cytometric detection of Listeria monocytogenes in milk. Appl. Environ. Microbiol. ; 52:689-695.

10. Jorgensen, et al. Manual of Clinical Microbiology, American Society for Microbiology, Washington, D.C.

11. Lee, W.H. and D. McClain. 1989. Laboratory Communication, No.57. USDA, F.S.I.S. Microbiology Division, Bethesda, MD.

12. Hayes, P.S., L.M. Graves, B. Swaminathan, G.W. Ajello, G.B. Marcolm, R.E. Weaver, R. Ransom, K. Deaver, B.D. Plikaytis, A. Schuchat, J.D. Wenger, R.W. Pinner, C.V. Broome, and The Listeria Study Group. 1992. Comparison of three selective enrichment methods for the isolation of Listeria monocytogenes from naturally contaminated foods. J. Food Prot.; 55:952-959.

ATCC is a registered trademark of the American Type Culture Collection.