A-7 DIFFERENTIAL AGAR

Technical Data #1542a / 2013.05.20

The A 7 Differential Agar is a selective solid medium used for the cultivation and isolation of Ureaplasma urealyticum and Mycoplasma sp. Fresh yeast extract, horse serum and enrichment enhance Ureaplasma and Mycoplasma growth. Penicillin G inhibits Gram positive bacteria.

 


 

FORMULA
in grams per liter purified filtered water

Casein Peptone

13,6

Soy Peptone

2,4

Potassium phosphate, dibasic

2,0

Sodium Chloride

4,0

L-Cysteine HCl

0,1

Dextrose

2,0

GHL, tripeptide

0,00002

Manganous Sulfate

0,15

Agar, Purified

10,5

Urea

1,0 g

Bio-X Enrichment

5,0 ml

Fresh Yeast Extract, pH 6,0

10,0

Penicillin G

1,0 MM units

Horse Serum, sterile

200,0 ml

pH 6,0 +/- 0,2 25 C

This approximate formula may be adjusted and/or enriched to obtain best results.


PRECAUTIONS
This medium is for IN VITRO diagnostic use only.


STORAGE
Store prepared media at 2-8 C protected from direct light.


SIGN OF DETERIORATION
Media should not be used if the expiry date has passed and if there are signs of contamination or deterioration (shrinking, cracking, evaporation or discoloration).


PROCEDURE
Prior to inoculate, the prepared medium should be brought to room temperature.

  1. Urethral, vaginal, cervical swabs, urine sediment and other specimens are inoculated on Mycoplasma Ureaplasma Transport Medium (2281).
  2. Transfer 0,1 ml of Mycoplasma-Ureaplasma Transport Medium into a U9 Broth tube (2361), 0,1 ml into Arginine Broth tube (2991) and 0,1 ml into A-7 Differential Medium (1542).
  3. Incubate broths aerobically at 35 C.
  4. Incubate plates at 35 C under reduced O2 conditions.
  5. Examine broths and plates each day for up 7 days.


QUALITY CONTROL

Results after 3 days at 35 C

Organisms

ATCC

Growth

Ureaplasma urealyticum

27815

+

Ureaplasma urealyticum

27618

+

Mycoplasma hominis

23114

+

Microscopic examination at low power (100x) shows brown colonies as Ureaplasma and typical "fried egg" colonies with a brown nucleus as Mycoplasma.


LIMITATIONS OF METHOD
This medium is only a part of the identification. Other tests may be required.


REFERENCES

  1. Balows, A., W.J. Hausler. 1981 Diagnostic Procedures for Bacterial, Mycotic and Parasitic Infections 6th ed.
  2. Kenny, G.E., 1985 Manual of Clinical Microbiology, 4th ed. Chap. 36, pp. 407-411, American Society for Microbiology.
  3. Lefebvre, J., Public Health Laboratory, D.S.C. St-Luc Hospital, Ste-Anne-de-Bellevue, Personnal Communications.
  4. Mac Faddin, Jean F., Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria Vol.1 1985 Baltimore, MD. Williams & Wilkins.
  5. Shepard, M.C. and C.D. Lanceford. 1976 Differential agar medium (A-7) for identification of Ureaplasma urealyticum (human T-strain) in primary cultures of clinical material. J. Clin. Microbiol. 3:613-625.


CATALOGUE NUMBERS

Prepared media    
Plates 60x15 mm 10/pkg 1542
     
Mycoplasma Ureaplasma Transport    
Tubes 12x75 mm 10/pkg 2281
     
Ureaplasma U9 Broth    
Tubes 12x75 mm 10/pkg 2361
     
Mycoplasma Arginine Broth    
Tubes 12x75 mm 10/pkg 2991

 


 





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