Chopped Meat Glucose Broth (CMG) will support the growth of most non-sporeforming and sporeforming anaerobes associated with human and animal infections and is also used in maintaining stock cultures. Chopped Meat Glucose Broth is a non-selective medium that is useful as a holding medium for stock and mixed cultures, for sporulation, proteolysis and toxin production by certain Clostridia spp. such as Clostridium novyi, Type A. This medium is also used for preservation of clostridial cultures by freezing. Chopped Meat Glucose Broth has the capacity to initiate growth from a minute inoculum and maintain viability of organisms over extended periods. It also allows slower growing organisms, within a mixed sample, to proliferate in the presence of rapid reproducing organisms. This medium is also used to demonstrate clostridial toxin production, sporulation and short chain organic acid production by gas chromatography. This medium is prepared, dispensed, stored and packaged under oxygen-free conditions to prevent the formation of oxidized products prior to use. 

        Anaerobe Systems PRAS Chopped Meat
                  Glucose Broth (CMG) AS-813

 

Formula

Lean Ground Beef, 500.0 g

Sodium Hydroxide (1N), 25.0 ml

Pancreatic Digest of Casein, 30.0 g

Yeast Extract, 5.0 g

Potassium Phosphate, Dibasic, 5.0 g

L-Cysteine, 0.5 g

Hemin (0.1% Soln), 5.0 ml

Vitamin K1 (1% Soln), 0.1 ml

Dextrose, 3.0 g

Distilled Water, 1000.0 ml

 

Final pH 7.1 +/- 0.3 at 25 degrees C.

Final volume 7.0 mL +/- 0.7.

                                                                                                               

Precautions

For IN VITRO DIAGNOSTIC USE only.  Approved biohazard precautions and aseptic techniques should be observed when using this product.  This product is for use only by properly-trained and qualified personnel.  Sterilize all biohazard waste prior to disposal.

Storage and Shelf Life

Storage:  Upon receipt, store at room temperature (13°C - 27°C) in original packaging until use.  Avoid overheating or freezing.  Do not use medium if there are signs of deterioration (discoloration or evaporation) or contamination.  The expiration date applies to the product in its original packaging and stored as directed.  Do not use product past the expiration date shown on the container. 

Shelf Life:  1 year from date of manufacture.

 

Procedure

Specimen Collection:  Specimens for anaerobic culture should be protected from air (oxygen) during collection, transport and processing of specimens.  Consult appropriate references for detailed instructions concerning collection and transport of anaerobes.

Methods for Use:  Chopped Meat Glucose Broth should be inoculated directly with clinical material.  Inoculated tubes should be immediately placed in an anaerobic atmosphere and incubated at 35 – 37^oC for 18 – 48 hours.  Additional periods of incubation may be necessary to recover some anaerobes.  Detailed instructions for processing anaerobic cultures can be found in the appropriate references.

 

Materials Required But Not Provided

Standard microbiological supplies and equipment such as loops, pipets, saline blanks, slides, staining supplies, microscope, incinerator or autoclave, incubators, anaerobic chamber or anaerobic jars, disinfectant, other culture media and serological and biochemical reagents.

 

Limitations

Chopped Meat Glucose Broth will not provide complete information for the identification of bacterial isolates.  Additional test procedures and media are required for complete identification.  Consult reference materials for additional information.

 

Quality Control

If used properly, this medium should support good growth of Clostridium tetani, Clostridium sporogenes, Prevotella melaninogenica and Fusobacterium necrophorum from a small inoculum (i.e. 0.01 ml of a 24 – 48 hour Lombard-Dowell (LD) Broth culture diluted to 3:1000).  Both C. tetani and C. sporogenes should produce characteristic spores, and C. sporogenes should exhibit proteolysis of the meat.  In addition, C. septicum and C. tetani should exhibit typical toxin production as demonstrated by mouse toxicity and mouse toxin neutralization (1).

The following organisms are routinely used for quality assurance testing at Anaerobe Systems.

Organism Tested	ATCC #	Results	Time (Hours)
Bacteroides fragilis	25285	Growth	24 h
Prevotella melaninogenica	25845	Growth	24 – 48 h
Bacteroides vulgatus	8482	Growth	24 h
Fusobacterium nucleatum	25586	Growth	24 – 48 h
Fusobacterium necrophorum	25286	Growth	24 – 48 h
Clostridium perfringens	13124	Growth	24 h
Clostridium novyi	7659	Growth	24 – 48 h
Peptostreptococcus anaerobius	27337	Growth	24 h
Propionibacterium acnes	6919	Growth	24 – 48 h
Staphylococcus aureus	25923	Growth	24 h

 

User Quality Control: The final determination to the extent and quantity of user laboratory quality control must be determined by the end user.

If sterility testing is to be performed on this product, the appropriate percentage of the original shipment amount should be incubated anaerobically and aerobically for 48 – 96 hours.

If the nutritive capacity of this media is to be tested for performance, it is recommended that the following ATCC organisms be evaluated for growth.

 

Organism	Expected
	Growth
B. fragilis	24 hrs
P. melaninogenica	48 hrs
C. perfringens	24 hrs
F. necrophorum	48 hrs
S. aureus	24 hrs

 

Physical Appearance:  Chopped Meat Glucose Broth should appear as a clear, golden-yellow liquid with meat particles in a 16mm x 100mm glass tube.

References

1.     Dowell, V. R., Jr. and T. M. Hawkins. 1974. Laboratory Methods in Anaerobic Bacteriology.  CDC Laboratory Manual. USDHEW C. D. C. Atlanta, GA 30333.

 

2.        Dowell, V. R., Jr. and G. L. Lombard. 1977. Presumptive Identification of Anaerobic Non-sporeforming Gram-negative Bacilli. USDHEW, CDC.  Atlanta, GA 30333.

 

3.        Dowell, V. R., G. L. Lombard, S. F. Thompson and A. Y. Armfield. 1977. Media for the Isolation, Characterization and Identification of Obligately Anaerobic Bacteria.  USDHEW, CDC. Atlanta, GA 30333.

 

4.        Holdeman, L. V., F. P. Cato and W. E. C. Moore. 1977. Anaerobe Laboratory Manual.  Virginia Polytechnic Institute and State University. Blacksburg, VA 24061.

 

5.        Jousimeie-Somer, L. V. , Summanen, P. Citron, D. M., Baron, E. J., Wexler, H. M. and S. M. Finegold. 2002. Wadsworth – KTL Anaerobic Bacteriology Manual. Star Publishing Co., Belmont, CA 94002.

 

6.        NCCLS. Quality Control for Commercially Prepared Microbiological Culture Media; Approved Standard- Third Edition. (2004). NCCLS document M22-A3. NCCLS, 940 West Valley Road, Suite 1400, Wayne, PA 19087-1898.

 

7.        Engelkirk, P. G., Duben-Engelkirk, J. and Dowell, V. R. 1992. Principles and Practices of Clinical Anaerobic Bacteriology. Star Publishing Co., Belmont, CA 94002.