342 MENINGOCOCCUS— GONOCOCCUS— CATARRH ALLS GROUP 
the organism in pure culture upon coagulated human blood serum 
and rej^roduced acute gonorrhea in men by urethral injections. 
Morphology.— The gonococcus occurs typically as a diplococcus, the 
proximated surfaces of pairs of cocci being flattened and elongated; 
they resemble coffee beans in shape. The longer diameter measures 
about 1.5 microns, the shorter diameter about 0.8 micron. The 
polymorphonuclear leukocytes of pus from cases of acute gonorrhea 
usually contain from one to several pairs of gonococci which are 
within the cytoplasm of the leukocyte but rarely or never within the 
nuclei. The organisms are also found within desquamated epithelial 
cells and occur free in pus as well. Gonococci are less numerous in 
the subacute and chronic stages of the disease, and they occur chiefly 
extracellularly, with occasional pairs or clusters of gonococci in epith- 
elial cells, less commonly in polymorphonuclear leukocytes. The 
organisms undergo degeneration rapidly, and even in pus from the 
more acute cases many large faintly staining cocci are found in asso- 
ciation with those which are more typical in morphology and staining. 
In the chronic stage of the disease degenerated forms are very common. 
The gonococcus is non-motile, and possesses no flagella; it forms no 
spores and capsules have not been detected. It stains with ordinary 
anilin dyes, but with some difficulty. It is Gram-negative. 
Isolation and Culture.— The organism does not grow upon ordinary 
media; for the first growths outside the human body, media con- 
taining uncoagulated protein, preferably that of human origin, are 
required. Blood, however, heated to (30° to 80° C. has been found to 
be excellent for this purpose. ^ Agar'^ smeared with sterile defibrinated 
blood, ^ or agar mixed with hydrocele or ascitic fluid (one part fluid, two 
parts agar) furnishes a satisfactory nutrient substrate. Pus from acute 
cases (after preliminary cleaning and sterilization of the external 
genitalia) spread upon one of the media described above, should exliibit 
colonies after twenty-four hours' incubation at 37° C. The colonies are 
minute, clear and colorless; they resemble small dewdrops and exhibit 
a tendency to coalesce. Organisms stained from these colonies remain 
typical in morphology only for one or two days. Very soon degenera- 
tion (autolysis) commences, and in a very short time the organisms are 
dead^ and partially dissolved. Secondary growths may be obtained 
from colonies, provided the inoculations are made within twenty-four 
to forty-eight hours from the time of plating. Ascitic broth, neutral 
in reaction, is an especially favorable medium for this purpose. 
The gonococcus is quite aerobic; little or no growth occurs in media 
from which oxygen is excluded. The temperature limits are very 
restricted; growth ceases below 30° C. and above 40° to 42° C. The 
optimum temperature is 37° C. The organism is extremely sensitive 
1 McLeod, Wheatley and Phelon: British Jour. Exp. Pathol., 1927, 8, 25. 
- Glycerin agar is better than ordinary agar for this purpose. 
3 The blood agar should be heated to 56° C. for thirty minutes to destroy its bacteri- 
cidal properties before use. 
* Warden: Jour. Infec. Dis., 1913, 12, 93. 
