CRITERION™ MACCONKEY AGAR WITH MUG

Cat. no. C6110 CRITERION™ MacConkey Agar with MUG 100gm
Cat. no. C6111 CRITERION™ MacConkey Agar with MUG 500gm
Cat. no. C6112 CRITERION™ MacConkey Agar with MUG 2kg
Cat. no. C6113 CRITERION™ MacConkey Agar with MUG 10kg
Cat. no. C6114 CRITERION™ MacConkey Agar with MUG 50kg

INTENDED USE

Hardy Diagnostics CRITERION™ MacConkey Agar with MUG is used for the presumptive identification of Escherichia coli .

This dehydrated culture medium is a raw material intended to be used in the making of prepared media products, which will require further processing, additional ingredients, or supplements.

SUMMARY

Trepeta and Edberg modified MacConkey Agar by the incorporation of 4-methylumbelliferyl-beta-D-glucuronide (MUG); the resulting medium allowed the authors to presumptively identify Escherichia coli from the primary plating medium within five minutes.(8) The above reaction is possible because most strains of E. coli (96-97%) produce glucuronidase, an enzyme that hydrolyzes MUG to 4-methylumbelliferone.(6) This compound fluoresces under long-wave ultraviolet light (366nm). The addition of MUG to the formulation allows beta-glucuronidase-positive strains of E. coli to fluoresce blue-green when examined under this wavelength of UV light.

FORMULA

Gram weight per liter: 50.0gm/L
Pancreatic Digest of Gelatin 17.0gm
Lactose 10.0gm
Sodium Chloride 5.0gm
Pancreatic Digest of Casein 1.5gm
Peptic Digest of Animal Tissue 1.5gm
Bile Salts No. 3 1.5gm
MUG 150.0mg
Neutral Red 30.0mg
Crystal Violet 1.0mg
Agar 13.5gm

Final pH 7.1 +/- 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 beige.

Store the prepared culture media at 2-8ºC.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 50.0gm of the dehydrated culture media in 1 liter of distilled or deionized water.

2. Heat to boiling and mix to dissolve completely.

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

4. Cool to 45-50ºC. Dispense into sterile containers as desired.

PROCEDURE AND INTERPRETATION OF RESULTS

For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. No. G37.

LIMITATIONS

Not all strains of Escherichia coli ferment lactose or produce beta-glucuronidase. Some strains of Salmonella and Shigella produce beta-glucuronidase and will fluoresce. A small percentage of Yersinia and streptococci have been reported to fluoresce.(5)

Additional biochemical and/or serological tests are necessary for definitive identification.

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
Escherichia coli
ATCC ® 25922
A 24hr 35°C Aerobic Pink colonies; fluoresce blue-green under UV light (366nm)
Shigella sonnei
ATCC ® 9290
A 24hr 35°C Aerobic Clear colonies; The colonies fluoresce blue-green under UV light (366nm)
Proteus mirabilis
ATCC ® 12453
A 24hr 35°C Aerobic Clear colonies; no fluorescence under UV light (366nm)

User Quality Control

PHYSICAL APPEARANCE

CRITERION™ MacConkey Agar with MUG powder should appear homogeneous, free-flowing, and beige in color. The prepared media should appear opalescent, and reddish-purple in color.

Note: This medium contains 4-methylumbelliferyl-beta-D-glucuronide (MUG). Most strains of E. coli possess an enzyme which breaks down MUG to a compound that fluoresces under a long-wave (366nm) ultra violet lamp.

REFERENCES

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

2. Anderson, N.L., et al. Cumitech 3B; Quality Systems in the Clinical Microbiology Laboratory, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C.

3. Feng, P.C.S. and P.A. Hartman. Appl. Envir. Microbiol.; 43:1982. p. 1320-1329.

4. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

5. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.

6. Killian, M. and P. Bulow. Acta. Pathol. Microbiol. Scand.; Sec. B, 84:1976. p. 245-251.

7. Robison, B.J. Appl. Envir. Microbiol.; 48:1984. p. 285-288.

8. Trepeta, R.W. and S.C. Edberg. J. Clin. Microbiol.; 19:1984. p. 172-174.


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

060616gr