638 THE GONOCOCCUS 



[Jenner's stain and Pappenheim's stain are both useful for staining films 

 of pus when searching for the gonococcus.] 



2. Cultural characteristics. 



Conditions of growth. The gonococcus is an aerobic organism which can 

 only be cultivated outside the body with some difficulty. It is necessary 

 to use special media and those containing serum give the best results. The 

 optimum temperature is 36-37 C. though growth takes place at all tem- 

 peratures between 21 and 39 C. The gonococcus ferments glucose but no 

 other sugar. 



Culture media. Broth. In ordinary broth at a temperature of 36 or 37 C. 

 the amount of growth is insignificant : towards the second day the medium 

 is cloudy, but subsequently becomes clear, a slight greyish deposit falling to 

 the bottom of the vessel. Vanned recommends veal broth containing no 

 peptone as a useful culture medium. The broth is evaporated to one-fourth 

 its volume and then one-third its volume of ascitic fluid is added. 



Bruschettini and Ansaldo obtained abundant growths by adding a few 

 drops of egg-yolk or egg-albumin to ordinary broth. According to these 

 observers the best medium is : 



Sterile beef broth, 10 c.c. 



Defibrinated blood, ...... 1 drop. 



Fresh white of egg, - 1 



Urine (Finger). In non-alkaline urine to which O5 per cent, peptone has 

 been added and the whole sterilized, the gonococcus grows better than in 

 broth. It produces a well-marked turbidity and a fairly copious precipitate. 

 Hammer prefers a highly albuminous urine sterilized either in the autoclave 

 or by filtration through porcelain. 



Acid gelatin (Turro). The gonococcus grows quite well at 22 C. in an acid 

 gelatin ordinary gelatin which has not been neutralized but the cultures 

 are delicate and growth fails after the third or fourth sub-culture. The 

 medium is not liquefied. 



Stab culture. After incubating for several days a very delicate white line 

 appears along the line of the stab . The amount of growth is always very poor. 



Single colonies, Single colonies appear as raised, viscous, white, hemi- 

 spherical points which always remain very small in size. 



Ordinary agar. A very scanty growth is obtained by sowing gonorrhceal 

 pus on the surface of ordinary agar : the necessary albuminoid material is 

 provided by the pus. The culture takes the form of a very thin glaze. 



Cultures have very little viability. It seems impossible to sub-cultivate on agar 

 for more than a generation or two and growth ceases generally after the second 

 sub-culture. Wildbolz however by using a slightly alkaline agar has occasionally 

 succeeded in sub-cultivating for several generations. Thalmann recommends 

 ordinary agar made neutral to phenolphthalem. Vanned uses ordinary 1*5 per 

 cent, agar made alkaline with 10 per cent, solution of sodium carbonate so that the 

 mixture turns litmus paper very slightly blue. 



Wertheim's agar. Tubes of sterilized agar (about 6 c.c. in each tube) are 

 liquefied by heat and cooled to 45 C. To each tube about 4 c.c. of human 

 blood serum or sterile ascitic fluid are added with aseptic precautions. The 

 contents of the tubes are mixed, sloped and allowed to cool. The tubes are 

 sown when the medium has set. 



It is an advantage both in this and in the following media to use glycerin-agar 

 instead of ordinary agar. 



Stroke cultures. Stroke cultures incubated for 2-3 days at 37 C. give a 

 narrow, thin, greyish, semi transparent band with a moist lustrous surface. 



