190 pathogenicity; chemotherapy 



characterised by liquefaction of the tissues around the wound 

 and the appearance of bubbles of gas within the muscular 

 tissue around the wound — hence the name " gas gangrene." 

 The gas may accumulate to such an extent that the infected 

 flesh crackles when handled. The local condition in the 

 wound is accompanied by pronounced shock, fever, and 

 collapse which, in the absence of therapeutic measures, is 

 usually fatal. 



Gas gangrene became serious during the fighting in Flanders 

 in 1914-18, when it was, for a time, one of the major causes 

 of death following wounding. Bacteriological examination 

 of the wound and the wound exudate showed heavy infection 

 with certain species of strictly anaerobic bacteria. The main 

 organisms concerned are three Clostridia: CI. welchii, CI. 

 septicum, and CI. oedematiens, placed in order of importance. 

 Other Clostridia, particularly CI. sporogenes and CI. 

 histolyticum, were often found in association with these three; 

 these are not themselves pathogenic, but it has been observed 

 that gas gangrene infections where the pathogenic organism 

 is accompanied by one of these non-pathogenic species, are 

 considerably more dangerous and progress with greater 

 rapidity than those where a simple infection of CI. welchii, 

 etc., exists. 



The Clostridia live a saprophytic existence in the intestinal 

 contents of many animals. Several distinct toxigenic types 

 of CI. welchii have been identified, of which some, types B, C, 

 and D, are associated with diseases of young farm animals. 

 CI. welchii, Type A, the causal organism in gas gangrene, 

 appears to lead a normal and harmless existence in the 

 intestinal contents of man and animals. The organisms are 

 voided with the faeces, and a certain proportion of them form 

 spores in the unsuitable environment of field and soil. The 

 spores can remain in the resting state on the soil for many 

 years, if necessary, until they eventually fall into an environ- 

 ment suitable for vegetative existence when they germinate 

 to form viable cells ready for multiplication. A suitable 

 environment for germination is provided by the tissues of a 



