DEHYDRATED CULTURE MEDIA 



97 



or three weeks if kept in the cold room. For mass cultivation of H. pertussis as 

 in vaccine production dissolve 1 gram of Proteose Peptone in 100 ml. of glycerol 

 solution used to rehydrate the medium. 



One pound of Bacto-Bordet Gengou Agar Base is sufficient for 15 liters of 

 medium. 



1 Am. inst. Pasteur, 20:731:1906. « Am. J. Pub. Health, 24:309:1934. 



2 Diagnostic Procedures and Reagents, 'Am. J. Pub. Health, 26:506:1936. 



3rd Edition: 141 : 1950. s Sixth Annual Year Book (1935-36), p. 200, 



3 Ann. inst. Pasteur, 30:503:1916. Suppl., Am. J. Pub. Health, 26:No. 3:1936. 

 * J. Am. Med. Assoc, 89:275:1927. » J. Path. Bact., 45:472: i937- 



5 J. Am. Med. Assoc, 95:263:1930. "Am. J. Clin. Path., 21:101:1951. 



BACTO 



END AMOEBA MEDIUM (B53) 



DEHYDRATED 



Beef Liver, Infusion from 272 g. 



Proteose Peptone, Difco 5.5 g. 



Disodium Phosphate 3 g. 



Sodium Chloride 2.7 g. 



Bacto-Agar 11 g. 



Bacto-Endamoeba Medium is a Liver Infusion Agar prepared especially for 

 the cultivation of Endamoeba histolytica from specimens. The formula cor- 

 responds to that recommended by Cleveland and Sanders^ and Cleveland and 

 Collier.2 



Cleveland and his associates made a comprehensive study of the cultivation of 

 E. histolytica. They used egg, serum and various other materials for cultivating 

 the amoeba and state^: "We feel however, that we really did not cultivate Enta- 

 moeba histolytica until we grew it on slants of liver infusion agar covered with 

 fresh horse serum-saline 1-6 and containing rice flour." They used about half 

 strength Bacto-Liver Infusion Agar in this study. Bacto-Endamoeba Medium 

 has been prepared to duplicate the modified Liver Infusion Agar described by 

 Cleveland and his co-workers. 



This medium, furthermore, is reported by them to be almost specific for 

 E. histolytica, as far as the intestinal amoebae of man are concerned. They 

 attempted to cultivate Endolimax nana, Dientamoeba fragilis, and E. coli and 

 failed, while E. histolytica grew abundantly. In a committee report Spector,^ 

 referee, states that the method of Cleveland and Collier using Bacto-Liver In- 

 fusion Agar overlaid with sterile serum-saline 1-6 was one of the best for practi- 

 cal diagnostic purposes and that Wassermann-negative human inactivated serum, 

 horse, or rabbit serum may be used. This report also mentions that other in- 

 testinal amoebae do not grow as readily in this culture medium as does E. 

 histolytica. 



To rehydrate the medium, suspend 33 grams of Bacto-Endamoeba Medium in 

 1000 ml. cold distilled water and heat to boiling to dissolve the medium com- 

 pletely. Distribute in tubes and sterilize in the autoclave for 15 minutes at 15 

 pounds pressure (121°C.). The final reaction of the medium will be pH 7.0. The 

 tubes are allowed to solidify in a slanted position. For the cultivation of E. histo- 

 lytica the slants are covered with Bacto-Horse Serum Saline 1-6 and a loopful 

 of sterilized Bacto-Rice Powder is added. Bacto-Rice Powder is sterilized in a 

 dry heat oven at 160°F. for one hour. Scorching must be prevented. These en- 

 richments are discussed in detail on pages 273 and 200. 



One pound of Bacto-Endamoeba Medium will make 13.7 liters of medium. 



1 Arch. Protiskenkunde, 70:223:1930. 3 Sixth Annual Year Book (1935-36), p. 130, 



* Am. J. Hyg., 12:606:1930. Suppl., Am. J. Pub. Health, 26:No. 3:1936, 



