DIPLOCOCCUS GONORRHOEA 549 



meat infusion-agar with one part of uncoagulated human ascitic fluid, 

 hydrocele fluid, or blood serum. The agar is melted and cooled to 45 

 before the serum is added. The mixture may then be slanted in the 

 test tube or poured into a Petri plate. One per cent of glucose may be 

 added. Cultures in fluid media may be obtained by similar additions of 

 serum to meat-infusion-pep ton-broth. Whole rabbit's blood added to 

 agar, or the swine-serum-nutrose medium of Wassermann 7 may occa- 

 sionally be used with success. 



Plates may be made by smearing for enrichment a drop of blood 

 from the finger over the surface of agar in the manner of Pfeiffer's 

 method for influenza-bacillus cultivation. Inoculations from gonorrheal 

 material are best made by surface smearing upon plates, since the gono- 

 coccus grows best in the presence of free oxygen. Growth becomes more 

 luxuriant after prolonged cultivation upon artificial media. The most 

 favorable reaction of media is neutrality or slight acidity. 



When the gonococcus has been successfully cultivated from pus upon 

 media without serum additions, the success has probably been due to 

 the substances carried over in the pus. The ease of cultivation differs 

 considerably with different strains of gonococci. Some grow very 

 heavily after first isolation, but the majority show a very delicate growth 

 even on rich ascitic glucose agar. After several generations of growth 

 on artificial media, however, the organism develops with increasing ease 

 and on simpler media. It may eventually be cultivated on plain agar, 

 especially when this is made of veal infusion. Recently a medium upon 

 which gonococci after first cultivation can be grown with ease has been 

 recommended by Edward B. Vedder. 8 The medium consists of a 

 1.5 to 1.75 per cent agar made with beef infusion neutral to phenol- 

 phthalein, and after clearing, 1 per cent of corn starch added. The corn 

 starch is best added after grinding with a little agar to avoid clumps, 

 this then being poured into the bulk of the agar and thoroughly mixed. 

 The medium should be sterilized at not over 15 Ibs. pressure to avoid 

 changes in the starch. Recently we have isolated several strains of 

 gonococci which grew very heavily on simple media without ascitic 

 fluid in the second culture generation. 



The gonococcus will develop sparsely under anaerobic conditions 



7 Wasserma-nn, Berl. klin. Woch., 1897. 



(Fifteen c.c. swine-serum, 35 c.e. of water, 3 c.c. glycerin, with two per cent 

 nutrose. The nutrose is dissolved by boiling and the solution sterilized. This 

 is then added to agar, in equal parts, and used in plates.) 



8 Vedder, Jour. Infec. Dis., May 15, 1915, xvi, 385. 



