THE GAS BACILLUS 75 



and cultivate by Wright's method. The fusiform lateral outgrowth 

 about the middle of the stab is characteristic. 



A more rapid method is to draw up the material, provided it be pus (tissue 

 scrapings may be emulsified in sterile salt solution) into a capillary bulb pipette. 

 Then seal off the end and heat the capillary bulb pipette and its contents in a water 

 bath at 80 C. for 15 minutes. Next break off the sealed tip and stick the pipette 

 into a deep tube of glucose agar. When the point reaches the bottom, force out the 

 material along the line of the stab as the pipette is withdrawn. Cover the surface of 

 the agar with sterile liquid petrolatum and incubate. Better anaerobic conditions 

 obtain where the Buchner or Wright method is employed. 



Tetanus produces no gas. Material for examination is best obtained with a bulb 

 pipette (containing a little sterile salt solution) which is plunged into the agar and the 

 salt solution forced out and drawn in where a proper growth is noted. 



Spores form in thirty-six to forty-eight hours. In injecting test animals it is 

 advisable to divide the material to be injected into two portions; one animal is 

 injected with the material alone, the second animal with tetanus antitoxin at the 

 same time the material is injected. Only the first animal dies with tetanic symptoms. 



B. aerogenes capsulatus (Welch, 1891). This bacillus is appar- 

 ently widely distributed. It is possibly the same organism as Klein's 

 B. enteritidis sporogenes, which is constantly present in faeces. It is a 

 large capsulated organism, which does not form chains. Spores are 

 produced on blood-serum. These are frequently absent on other 

 media. It is questioned whether its pathogenicity is other than ex- 

 ceedingly feeble, the presence of the bacillus in emphysematous find- 

 ings at postmortem being attributed to terminal or cadaveric invasion. 



Cases, however, in the Philippines, have been reported following carabao horn 

 wounds, in which most serious and fatal results attended emphysematous lesions 

 showing this bacillus. The isolation of a Gram positive bacillus from a lacerated 

 wound discharge, even in the absence of emphysema, is almost diagnostic. 



In milk cultures we have coagulation and from the subsequent development 

 of gas the disruption of the coagulum into shreds. An odor of butyric acid is 

 developed. 



Cultures in litmus milk show these shreds plastered against the sides of the tube 

 and showing a pink color. 



It is the cause of "foamy organs" occasionally present at autopsy. 



The best method of diagnosis is to inoculate the culture or material 

 into the ear vein of a rabbit, kill it and then incubate the body at 37 C. 

 Gas is generated in the organs in a few hours. 



Achalme isolated a large bacillus from a fatal case of rheumatism which is now 

 considered as having no relation to acute rheumatism and which was probably B. 

 aerogenes capsulatus. 



Kendall has called attention to the importance of this organism in a certain 

 proportion of cases of summer diarrhcea of infants. (See under chapter on faeces.) 



