260 DIFGO MANUAL 



to this formula is satisfactory for the isolation of Neisseria gonorrhoeae from 

 gonococcal infection in the male and female. In 2 per cent concentration Proteose 

 Peptone No. 3 is an excellent carrying fluid for suspending suspected gonococcal 

 specimens. The suitability of Proteose Peptone No. 3 in the preparation of media 

 for the isolation of A^. gonorrhoeae from all types of gonococcal infection is amply 

 demonstrated by the many references to the use of this peptone for this purpose. 

 Among others Peizer and Steffen,^ Bucca,* Morton and Leberman,^ Landy and 

 Gerstung,^ Lankford and Skaggs^ and the "Diagnostic Procedures and Reagents"^ 

 of the American Public Health Association used Proteose Peptone No. 3 in media 

 for gonococcal studies. Continued study of the nutritional requirements of gono- 

 cocci has shown that a small percentage are exacting in their growth require- 

 ments. Chocolate Agars, prepared with Bacto-Proteose No. 3 Agar and Bacto- 

 Hemoglobin, enriched with Bacto-Supplement A or Bacto-Supplement B, have 

 proved excellent for the isolation of all types of N, gonorrhoeae. The method for 

 the isolation of this organism is discussed in detail under Bacto-Proteose No. 3 

 Agar, page 116, or Bacto-G C Medium Base, page 122. 



Proteose Peptone No. 3 is well suited for the preparation of media for cultiva- 

 tion of C orynebacterium diphtheriae. This peptone is employed in the preparation 

 of Bacto-Dextrose Proteose No. 3 Agar, as discussed on page 147, for isolation of 

 the diphtheria bacillus. Levin^ used Proteose Peptone No. 3 in media for the 

 isolation of meningococci and the diphtheria bacillus. 



This peptone is well suited for the growth of a large variety of organisms 

 including streptococci, staphylococci, meningococci, pneumococci, anaerobes and 

 aerobes. In addition to the media listed above it is employed in Bacto-Phenol Red 

 Carbohydrate Media discussed on page 187, 189, Bacto-Purple Broth Media, 

 page 189, 190, and other fermentation media, Bacto-A C Broth and Bacto-A C 

 Medium, pages 201 and 202. 



1 Seventh Annual Year Book (1936-37) p. 125. ^ U. S. Naval Med. Bull., 43:409:1944. 

 Suppl., Am. J. Pub. Health, 27: No. 3:1937. ^ J. Immunol., 51:269:1945. 



2 Bull. Genitoinfectious Diseases, Mass. Dept. '^ Arch. Biochem., 9:265:1946. 



Pub. Health, 2: No. 9:1938. ^ Diagnostic Procedures and Reagents, 3rd Edi- 



8 Venereal Disease Inform., 23:224:1942. tion: 119: 1950. 



* J. Bact., 46:133:1943. "J. Bact., 46:235:1943. 



B AGTO-TR YPTONE ( B 1 23 ) 



Bacto-Tryptone was developed in our search for a peptone particularly suitable 

 for the elaboration of indole by bacteria. Tests for the presence or absence of 

 indole as a by-product of bacterial metabolism are of definite value in the identifi- 

 cation and classification of bacteria. However, unless the culture medium in 

 which the organisms are grown can be relied upon to support indole production 

 uniformly, the results of the test are misleading and fallacious as shown by 

 Tilley.i 



Indole production is dependent upon the presence of the tryptophane group 

 in the medium,^'^.* Bacto-Tryptone is exceptionally well suited for use in tests 

 for indole production because it is rich in this form of nitrogen. Strong indole tests 

 are possible after incubation of the cultures for 15 or 16 hours in a 1 per cent 

 solution of Bacto-Tryptone. The reaction, furthermore, will remain strong even 

 when cultures are incubated for 4—5 days. The advantages of securing a positive 

 indole test, particularly after a relatively short incubation period, are obvious. 

 "Standard Methods for the Examination of Water and Sewage"^ of the American 

 Public Health Association and the American Water Works Association, and "Pure 

 Culture Study of Bacteria"^ of the Society of American Bacteriologists, specify 

 the use of Bacto-Tryptone in demonstrating the presence of indole. 



