GAS GANGRENE 8 1 



deep agar stab of freshly sterilized glucose agar is made and inoculated. The sur- 

 face of this is then covered with sterile paraffin oil. The proper amount of pyro- 

 gallic acid is then deposited in a salt mouth bottle. The rubber stopper with the 

 glass and rubber tubing is then firmly pushed in and connection made with a filter 

 pump. 



In five to ten minutes almost all the air will be exhausted when the Hofmann 

 clamp is screwed up tight and the bottle disconnected from the vacuum pump. 

 The glass tubing end is then inserted into a graduate holding 10% caustic soda 

 solution, the Hofmann clamp unscrewed, and the necessary amount of caustic soda 

 having been run in, as noted under Buchner method, we again close the screw clamp 

 and incubate. 



GENERAL CONSIDERATIONS OF PATHOGENIC ANAEROBES 



Dean and others, working with gas gangrene wounds, have brought 

 out some very practical points in connection with the three important 

 anaerobes found in such wounds, viz.: B. aero genes capsulalus, B. adem- 

 atis maligni and B. tetani. 



They found an egg broth, made by shaking up the white and yolk of i egg in 

 300 c.c. water a most excellent culture medium. This medium was tubed and 

 sterilized, after which it was liberally inoculated with material from the wounds. 

 After inoculation the tube was heated to 8oC. for one-half hour and then incubated 

 anaerobically.. The gas bacillus was present in abundance in such cultures after two 

 or three days' incubation, while the bacillus of malignant oedema later on became the 

 predominant organism. The tetanus bacillus only appeared after a prolonged period 

 seven to ten days. The bacillus of malignant oedema grew best on Dorsett's egg 

 medium and in two days began to liquefy the slant with a bluish-black discolora- 

 tion. The growth at first was profuse and creamy white. On glucose agar there 

 was much less gas production than with the gas bacillus. The malignant oedema 

 organisms were as a rule Gram-negative on glucose agar but they were distinctly 

 Gram-positive on Dorsett's medium. The spores were oval in shape, usually 

 located near the end of the rod. The gas bacillus grew well on Dorsett's medium 

 but less vigorously. In glucose agar stabs so much gas was formed that the 

 cotton plug and much of the culture medium tended to be expelled from the 

 tube. The spores form well on Dorsett's medium but not in glucose agar and 

 show as oval bodies distending the central portion of the rod. 



Subcutaneous inoculation of the gas bacillus and that of malignant 

 oedema rarely produced death in guinea-pigs. 



As regarded the tetanus bacillus they tried various methods of bacteriological 

 diagnosis. The examination of smears from wounds was unsatisfactory in search 

 for "drum-stick" spores. In broth cultures the spores were not present until after 

 several days and in mixed cultures it was difficult to be sure that the terminal spores 

 were those of tetanus and not atypical malignant oedema spores. The best method 

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