314 BACTERIA AND DISEASE 



It is a non-liquefying organism, pathogenic for white mice (producing 

 septicsemia). It grows on ordinary laboratory media, producing a 

 viscid tenacious culture. 



5. B. coli communis and many putrefactive germs commonly 

 occur in suppurative conditions, but they are not restricted to such 

 disorders (see p. 46). 



6. Micrococcus gonorrhcece (Neisser, 1879). This organism is 

 more frequently spoken of as a diplococcus. It occurs at the acute 

 stage of the disease (and in the purulent secretion of gonorrhoeal 

 conjunctivitis), but is not readily differentiated from other similar 

 diplococci except by laboratory methods. Each element of the diplo- 

 coccus presents a straight or concave surface to its fellow. A very 

 marked concavity indicates commencing fission. The position which 

 these diplococci take up in pus is intracellular, and they are arranged 

 more or less definitely around the nucleus. In chronic gonorrhoea 



the diplococci are diminished in number. 

 Difficulty has often been found in culti- 

 vating the organism in artificial media 

 outside the body. Wertheim and others 

 have suggested special formulae for the 

 preparation of suitable media, but it is a 

 comparatively simple matter to secure 

 cultures on agar plates smeared with 

 human blood from a pricked finger. The 

 plate is incubated at 37 C. At the end 

 of twenty-four hours small raised grey 

 colonies appear, which at about the end 



FiG.27.-DiagramofGouococcus. of f r days show adult growth. The 



margin is uneven, and the centre more 



opaque than the rest of the colony. This diplococcus is readily 

 killed, and sub-cultures must be frequently made to retain vitality 

 and virulence. Light, desiccation, and a temperature of 55 C. 

 all act germicidally. The organism stains readily with Lofner's blue, 

 but is decolorised by Gram's method. It is more or less strictly 

 parasitic to man, and has been definitely proved to be the cause 

 of gonorrhoea. A toxin has been separated. The shape, size, 

 character of growth, intracellular position, and staining pro- 

 perties of the gonococcus assist in differentiating it from various 

 similar diplococci.* An organism not greatly different from the 

 gonococcus is the diplococcus intracellularis meningitidis isolated by 

 Weichselbaum from cases of cerebro-spinal meningitis. It occurs in 

 the interior of leucocytes. 



Such are the chief organisms associated with suppuration. In 



the condition known as septicaemia, these organisms multiply in the 



* See Tram. Jmner Inst. (First Series), A. G. R. Foulerton, F.R.C.S., pp. 40-81. 



