|Cat. no. Y25||MGP Broth, 13x100mm Tube, 2ml||20 or 100 tubes/box|
Hardy Diagnostics MGP Broth is used to differentiate enterococci based on the ability to acidify the carbohydrate methyl-alpha-D-glucopyranoside (MGP).
Enterococcus faecalis and Enterococcus faecium are becoming more frequently identified as pathogens, particularly in nosocomial infections. The occurrence of vancomycin resistance in these two species has increased in recent years. Enterococcus gallinarum and Enterococcus casseliflavus , while rarely involved in clinical infection, show intrinsic resistance to vancomycin due to the v anC gene. This intrinsic vancomycin resistance makes E. gallinarum and E. casseliflavus difficult to differentiate from the rest of the enterococci by conventional biochemical tests. (1)
Typically, E. gallinarum can be differentiated from E. faecium based on motility, E. gallinarum being motile, while E. faecium is not. However, non-motile strains of E. gallinarum have recently been identified. Correct identification of these strains is critical due to their difference in pathogenicity. E. gallinarum and E. casseliflavus are capable of acidifying methyl-alpha-D-glucopyranoside, but E. faecalis and E. faecium are not. This makes the MGP test useful in preventing the misidentification of vancomycin-resistant E. gallinarum as vancomycin-resistant E. faecium . (2) For a rapid MGP reaction (5 hours), please use our Rapid MGP Medium (Cat. no. Z225).
Ingredients per liter of deionized water:*
|Pancreatic Digest of Casein||10.0gm|
Final pH 7.4 +/- 0.2 at 25ºC.
* Adjusted and/or supplemented as required to meet performance standards.
STORAGE AND SHELF LIFE
Storage: Upon receipt store at 2-8ºC. away from direct light. Media should not be used if there are any signs of deterioration, discoloration, contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.
1. Inoculate the MGP Broth by lightly touching a single, isolated colony. Do not use a heavy inoculum with this product.
2. Incubate aerobically at 35ºC. for 24 hours.
3. Observe for yellow color change in the media.
INTERPRETATION OF RESULTS
A yellow color change is a positive test for acidification of MGP. Red or orange colored media is a negative test.
Typical results are as follows: (1)
A heavy inoculum may give false-positive results.
Extended incubation times may result in false-positive reactions.
MGP Broth is used to aid in the differentiation of the enterococci. Additional biochemical tests are required for complete identification. See listed references for more information. (1-6)
MATERIALS REQUIRED BUT NOT PROVIDED
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|
ATCC ® 49573
|A||24hr||35°C||Aerobic||Growth; media turns yellow|
ATCC ® 29212
|A||24hr||35°C||Aerobic||Growth; no color change|
User Quality Control
MGP Broth should appear clear with a slight opalescence, and red in color.
Enterococcus gallinarum (ATCC ® 49573) growing in MGP Broth (Cat. no. Y25). Incubated aerobically for 24 hours at 35ºC.
Enterococcus faecalis (ATCC ® 29212) growing in MGP Broth (Cat. no. Y25). Incubated aerobically for 24 hours at 3ºC.
Uninoculated tube of MGP Broth (Cat. no. Y25).
1. Devriese, L.A., et. al. 1996. J. Clinical Micro.; 34: 2607-2608.
2. Turenne, C.Y., et. al. 1998. J. Clinical Micro.; 36:2333-2335.
3. Gin, A.S. and G.G. Zhanel. 1996. Vancomycin-Resistant Enterococci. The Annals of Pharmacotherapy.; 30:615-624.
4. Facklam, R.R. and M.D. Collins. 1989. Identification of Enterococcus species isolated from human infections by a conventional test scheme. J. Clinical Micro.; 27:731-734.
5. Jorgensen., et al. Manual of Clinical Microbiology, American Society for Microbiology, Washington, D.C.
6. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.
ATCC is a registered trademark of the American Type Culture Collection.