THE GONOCOCCUS GROUP 303 



required. Agar 1 smeared with sterile defibrinated blood, 2 or agar mixed 

 with hydrocele or ascitic fluid (one part fluid, two parts agar) furnishes 

 a satisfactory nutrient substrate. Pus from acute, cases (after pre- 

 liminary cleaning and sterilization of the external genitalia) spread 

 upon one of the media described above, should exhibit colonies after 

 twenty-four hours' incubation at 37 C. The colonies are minute, 

 clear and colorless; they resemble small dewdrops and exhibit a ten- 

 dency to coalesce. Organisms stained from these colonies remain 

 typical in morphology only for one or two days. Very soon degen- 

 eration (autolysis) commences, and in a very short time the organisms 

 are dead 3 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 is an 

 especially favorable medium for this purpose. 



The gonococcus is markedly 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 to desiccation, and cultures die spontaneously within six 

 to eight days. Repeated transfers of the cocci at intervals of two to 

 three days will prolong the life of the culture almost indefinitely, pro- 

 vided they are maintained at 37 C. The organisms are very readily 

 killed (outside the body) by the usual disinfectants. Gonococci in 

 the urethra can not be killed readily by chemical disinfectants; the 

 organisms penetrate rather deeply, into the walls and the disinfectant 

 can not reach them in sufficient concentration to be effective. This 

 is particularly true of the subacute and chronic stages of the disease. 



Products of Growth. No enzymes have been detected in cultures of 

 gonococci. Culturally the organism is inert; no development occurs 

 in ordinary media. Acid is produced in dextrose-ascitic broth, but no 

 other sugars are fermented. (See page 299 for comparison of cultural 

 characters of gonococcus and similar Gram-negative diplococci.) 



. Toxins. No soluble (exo-) toxin has been demonstrated in cultures 

 of gonococci. 



Finger, Ghon and Schlagenhaufer, 4 Nicolaysen, 5 Wassermann 6 and 

 de Christmas 7 have shown that the cell substance itself is toxic. 



1 Glycerin agar is better than ordinary agar for this purpose. 



2 The blood agar should be heated to 56 C. for thirty minutes to destroy its bacteri- 

 cidal properties before use. 



3 Warden, Jour. Infec. Dis., 1913, xii, 93. 



4 Arch. f. Derm. u. Syph., 1894, xxviii, Nos. 1 and 2; Cent. f. Bakt., 1894, xvi, 350. 



5 Cent. f. Bakt., 1897, xxii, 305. 6 Zeit. f. Hyg., 1898, xxvii, 307. 

 7 Ann. Inst. Past., 1900, 349. 



