222 APPLIED BACTERIOLOGY 



60N0REH(EA. 



Specific organism first discovered by Neisser — Morphology — Cultivated 

 by Eumm — Method of staining — Special media necessary for culture 

 — Occurrence and pathogenesis — Pathogenicity demonstrated by 

 Bumm — In gonorrhcea the gonococeus is associated with other 

 micro-organisms — Eesearches of Bosc — Bacteriological diagnosis — 

 Practical precautions. 



The diplococcus which is the cause of this disease was 

 first discovered by Neisser in the year 1879, and six years 

 later was cultivated by Bumm on blood serum. The gono- 

 coceus is a facultative aerobe, but grows best when oxygen 

 is excluded ; it is a very strict parasite, and can only be 

 cultivated on special media, and must be recultured at 

 frequent intervals, or its vitality is lost. 



It grows only at blood-heat. The organisms occur in 

 pairs, and appear somewhat biscuit-shaped when seen by 

 a high power. The thermal death-point is shown by Stern- 

 berg to be about 60° C. 



Method of Staining. — The gonococeus is stained best by 

 Loffler's methylene blue, and is decolourised by Gram's 

 method, which serves to distinguish it from certain other 

 diplococci that occur in gonorrhceal pus, but not from all. 



Growth on Media. — Bumm succeeded in growing the gono- 

 coceus on human blood serum, while other observers report 

 good results on blood serum agar, blood serum gelatine, 

 plover egg albumin, etc. The best results seem to have 

 been obtained by Wertheim, who prefers a mixture of two 

 parts of glycerine agar and one part of human blood serum; 

 on this medium he obtained well-defined growths in so short 

 a time as twenty-four hours after inoculation. A pure 

 culture of the gonococeus assumes a raised appearance 

 similar to a mulberry, and is of a yellowish- white colour. 



