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Enriched Tryptic Soy Agar with Nalidixic Acid and Vancomycin Agar (ETSA-NV)

Enriched Tryptic Soy Agar with Nalidixic Acid and Vacomycin (ETSA-NV) is an enriched selective medium for the cultivation and isolation of most gram-negative anaerobic and other fastidious bacteria. ETSA-NV is an enriched selective medium supplemented with diluted laked sheep blood and sheep serum to facilitate the recovery and pigmentation of black pigmenting Prevotella and Porphyromonas spp.  It is also supplemented with nalidixic acid and vancomycin to inhibit most gram-positive anaerobes.  This medium is prepared, stored, and dispensed under oxygen-free conditions to prevent the formation of oxidized products prior to use.

       Anaerobe Systems PRAS Enriched Tryptic
                Soy Agar w/ Nalidixic Acid &
               Vancomycin (ETSA-NV) AS-547

View the full product insertETSA-NV Insert.pdf

Enriched Tryptic Soy Agar W/ Nalidixic Acid and Vancomycin Agar Products

 Item #





ETSA-NV mono plate 

4 plates 




Pancreatic Digest of Casein, 15.0 g

Agar, 15.0 g

Soy Peptone, 5.0 g

Sodium Chloride, 5.0 g

Yeast Extract, 1.0 g

Dextrose, 1.0 g

Sodium Succinate, 0.5 g

Sodium Formate, 0.5 g

Sodium Fumarate, 1.0 g

Sodium Carbonate, 0.4 g

L-Cysteine, 0.4 g

Potassium Nitrate, 0.5 g

Hemin (0.1% Soln), 1.0 ml

Sodium Lactate, 0.6 g

Menadione, 1.0 mg

Nalidixic Acid, 10.0 mg

Vancomycin, 2.5 mg

Diluted Laked Sheep Blood, 30.0 ml

Sheep Serum, 40.0 ml

Distilled Water, 930.0 ml


Final pH 7.3 +/- 0.3 at 25 degrees C.

Final weight 20.0 g +/- 2.0 for AS-547.



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 container until use.  Avoid overheating or freezing.  Do not use medium if there are signs of deterioration (shrinking, cracking or discoloration due to oxidation of media) 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:  90 days from date of manufacture.



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

Methods for Use:  ETSA-NV should be inoculated directly with clinical material or a broth that has been previously inoculated from clinical material.  Inoculated plates should be streaked to obtain isolated colonies, immediately placed in an anaerobic atmosphere and incubated at 35-37oC 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, saline blanks, slides, staining supplies, microscope, incinerator / autoclave, incubators, anaerobic chamber, other culture media and serological and biochemical reagents.



ETSA-NV will not provide complete information for identification of bacterial isolates.  Additional test procedures and media are required for complete identification.  It is recommended that a non-selective medium such as Anaerobic Brucella Blood Agar also be inoculated from clinical specimens to assure growth of all species present.  Consult reference materials for additional information.


Quality Control

This medium should support good growth of many fastidious and non-fastidious anaerobes isolated from clinical specimens.  It should also facilitate pigmentation of the black pigmenting Prevotella and Porphyromonas spp.

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

Organism Tested



Time (Hours)

Special Reaction

Bacteroides fragilis



24 h


Prevotella melaninogenica



24-48 h


Fusobacterium necrophorum



24-48 h


Fusobacterium nucleatum



24 h


Clostridium perfringens


No Growth



Peptostreptococcus anaerobius


No Growth



Prevotella intermedia



24-48 h


Propionibacterium acnes


No Growth



Eubacterium lentum


No Growth



Actinomyces viscosus


No Growth



Porphyromonas gingivalis



24-48 h


                                             * Pigment production may require more than 48 hours of incubation.

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/inhibitory capacity of this medium is to be tested for performance, it is recommended that the following ATCC organisms be evaluated for growth/inhibition.



Expected Growth

Special Reaction

B. fragilis

24 hrs


P. melaninogenica

48 hrs


F. nucleatum

24 hrs


C. perfringens



P. anaerobius



P. intermedia

48 hrs


P. gingivalis

48 hrs



Physical Appearance:  ETSA-NV should appear opaque to translucent and amber in color in a 15mm x 100mm over-fill sized plate (AS-547).



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


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


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


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


5.        NCCLSQuality 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.