144 DIFGO MANUAL 



medium prepared in this way, reactions typical of those described by Wilson and 

 Blair are routinely obtained. The characteristic precipitate present in the medium 

 should be evenly dispersed by twirling the flask just prior to pouring plates. Best 

 results are obtained when the medium is dissolved and used immediately. If it is 

 necessary to prepare the medium several days before using, it should be poured 

 into plates and stored in a cold moist atmosphere to prevent drying. The melted 

 medium should not be allowed to solidify in flasks and be remelted. The final 

 reaction of the medium will be pH 7.7. 



One pound of Bacto-Bismuth Sulfite Agar will make 8.7 liters of medium. 



1 Standard Methods for the Examination of » Am. J. Pub. Health, 28:1065:1938. 

 Dairy Products, 9th Edition: 165:1948. ^ ^^ J. Lab. Clin, Med., 24:461:1939. 



2 Diagnostic Procedures and Reagents, 3rd Edi- "Am. J. Pub. Health, 28:762:1938. 



tion: 212: 1950. ^ J. Am. Water Works Assoc, 30:124:1938. 



3J, Hyg., 21:392:1923. 13 J. Lab. Clin. Med., 23:1185:1938. 



* Brit. Med. J., 1:1061:1928. i* Public Health Reports, 65:1075:1950. 



^ J. Path. Bact., 29:310:1926. ^^ J. Milk and Food Tech., j 3:^26: 1950 



'i 



Hyg., 26:374:1927. i^Proc. 22. Ann_^ Mtg. N. E. Cqnf. Lab. Work- 



Hyg., 31:139:1931- ers P " 



Bact., 34:565: 1937- 1950. 



Hyg., 31:139:1931. ers Pullorum Disease Control Burlington, Vt. 



165:1937- 



BACTO 



BRILLIANT GREEN AGAR (B285) 



DEHYDRATED 



Bacto- Yeast Extract 3 g. 



Proteose Peptone No. 3, Difco . . 10 g. 



Sodium Chloride 5 g. 



Bacto-Lactose 10 g. 



Saccharose, Difco 10 g. 



Bacto-Phenol Red 0.08 g. 



Bacto-Brilliant Green 0.0125 g. 



Bacto-Agar 20 g. 



Bacto-Brilliant Green Agar is a highly selective medium recommended for the 

 isolation of Salmonella, other than typhosa, directly from stools or other ma- 

 terials suspected of containing these organisms, or after preliminary enrichment 

 in Tetrathionate Broth. 



The use of a Brilliant Green Agar as a primary plating medium for the isola- 

 tion of Salmonella was first described by Kristensen, Lester, and Jurgens^ who 

 reported it useful for the differentiation of "paratyphoid B" from other intestinal 

 Gram-negative bacilli. Later, Kauffmann^ modified their formula and used the 

 Brilliant Green Agar in conjunction with a Tetrathionate Broth for the isolation 

 of Salmonella from stools. Galton and Quan^ increased their positive Salmonella 

 findings by 164 per cent by the use of Tetrathionate Broth and plating on Bril- 

 liant Green Agar. Broh-Kahn* and Edwards^ similarly employed the Kauffmann 

 modification of Brilliant Green Agar with superior results. 



Bacto-Brilliant Green Agar is a slight modification of the medium as described 

 by Kauffmann. The outstanding selectivity of this medium permits the use of 

 moderately heavy inocula, which should be evenly distributed over the surface. 

 Inoculation with heavy suspensions of stools or other materials suspected of con- 

 taining Salmonella usually results in an almost pure culture of these organisms. 

 Growth of other bacteria is almost completely inhibited. Following incubation at 

 37°G. for 18-24 hours the plates are examined for typical Salmonella colonies. 

 These appear as slightly pink-white opaque colonies surrounded by a brilliant red 

 medium. The few lactose or sucrose fermenting organisms which may develop 

 on the medium are readily differentiated due to the formation of a yellow-green 



