BIOLOGY OF CLOSTRIDIUM WELCHII 409 



Artificial cultivation and cultivation for long periods of time 

 render the organism more resistant to heat. The thermal death 

 points of cultures grown in sterile milk are different from those 

 grown in glucose-liver broth. Sub-cultures in all cases give 

 uniform results under identical conditions. 



Cultures from fecal sources are more resistant to heat than 

 those from milk. Pasteurization kills all vegetative forms of 

 Clostridium Welchii. 



XI. PATHOGENICITY 



1. Historical. Since the spores of Clostridium Welchii have 

 such a wide distribution in nature, in the air, soil and dust, on 

 the bodies of human beings and animals, on food-stuffs and in 

 the intestinal tract and feces of animals, the question of the 

 possible pathological significance of these spores is an important 

 one. A review of the literature since Welch's discovery of the 

 gas bacillus shows not only a wide diversity of opinion in regard 

 to the pathogenicity of this organism but also varied conceptions 

 regarding its toxicity. 



In preantiseptic times, especially in military surgery, wound 

 infection by this organism was much more common than today 

 yet cases are being reported at the present time. In early days 

 the infection was thought by some writers to be due to the 

 penetration of air into the tissues but by most investigators to 

 the decomposition of adipose and bone marrow tissues brought 

 about by contact with the atmosphere. Since the observations 

 of Welch and his associates in the '90's, the investigations have 

 demonstrated that the most common and important cause of 

 gaseous phlegmons or emphysematous gangrene is the "gas 

 bacillus" or Clostridium Welchii. Fraenkel, 1902, attributed the 

 general symptoms in this infection to an intoxication due to the 

 decomposition products of the infected tissues while Metchnikoff, 

 1908, Korentchewsky, 1909, Kamen, 1904, Herter, 1907, Passini, 

 1905 and others ascribe them to ordinary endotoxin absorption. 

 Other views expressed ascribed the locally destructive effects of 

 the gas bacillus to mechanical action or to the production of 

 fatty acids causing acidosis which brought about fatal effects. 



THE JOURNAL OF BACTERIOLOGY, VOL. V, NO. ( 



