ONPG-PENYLALANINE AGAR-MOTILITY-SULFATE MEDIUM (ONPG-PA-M-S)

Technical Data #2737a / 2013.07.02

ONPG-PA-M-S is a semi-solid, single-tube, multiple-test medium used for screening Enterobacteriaceae in enteric and other clinical specimens. This medium allows the detection of motility, -galactosidase, phenylalanine deaminase, and H2S production.

 


 

FORMULA
in grams per liter purified filtered water

Casein Peptone

5,0

Yeast Extract

1,0

L-Phenylalanine

2,0

Sodium Chloride

5,0

-Nitrophenyl--D-galactopyranoside

0,25

Sodium Phosphate, dibasic

0,75

Ferrous Ammonium Sulfate

0,4

Sodium Thiosulfate

0,4

Agar

3,0

pH 7,4 +/- 0,2 à 25º 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 2-8º C protected from direct light.


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


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

  1. Inoculate tubes with one colony from an overnight growth, with straight needle till 1 cm from the bottom of the tube.
  2. Incubate at 35º C for 24 hours caps loosened.
  3. Examine for motility, presence of H2S, positive -galactosidase (yellow ring at the top of medium). Add 2-3 drops of Ferric Chloride 12% (8562). Positive Phenylalanine deaminase will give a dark green ring.


QUALITY CONTROL

Results after 24 hrs at 35ºC

Organisms

ATCC

Motility

H2S

ONPG

PHENYLALANINE

Salmonella typhimurium

14028

+

+

-

-

Shigella flexneri

12022

-

-

-

-

Proteus mirabilis

12453

+

+

-

+

Escherichia coli

25922

+

-

+

-


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


REFERENCES

  1. Borczyk, A.A., J.S.Thompson 1984 Use of a single-tube medium -nitrophenyl--D-galactopyranoside-phenylalanine-motility sulfate for screening of pathogenic members of the family Enterobacteriaceae. J. Clin. Microbiol. 20:136-137.
  2. Edwards, P.R., W.H. Ewing 1972 Identification of Enterobacteriaceae 3rd ed. Burgess Publishing Co. Minneapolis
  3. Gillies, R.R., 1956 An evaluation of two composite media for preliminary identification of Shigella and Salmonella. Am. J. Clin. Pathol 9:368-371
  4. Giammanco, G., A. Carmeni 1971 The detection of Salmonella and Shigella with the aid of a new medium for the simultaneous assay of beta-galactosidase, phenylalanine-deaminase and motility Ann. Inst. Pasteur (Paris) 120:525-530


CATALOGUE NUMBERS

ONPG-PA-M-S    
Prepared media    
Tubes, 13x100 mm, 4 ml 10/pkg 2737
  100/box 2737-H
     
ONPG-PA-M W/O SULFATE    
Prepared media    
Tubes, 13x100 mm, 4 ml 10/pkg 2736

 


 

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