364 VETERINARY BACTERIOLOGY 



From the veterinary standpoint, the organism is of principal 

 interest, not so much because of its slight pathogenic power, as 

 the fact that it may be confused upon isolation with other spore- 

 bearing anaerobes. 



Immunity. McCampbell has found that the nitrates of 

 B. welchil grown in dextrose bouillon are toxic, but showed the 

 toxicity to be due to the butyric acid produced. No true toxin 

 nor endotoxin could be demonstrated. The acids are also hemo- 

 lytic and leukocytotoxic. Opsonins are present in normal and 

 in increased quantities in immune sera, as are also specific bacteri- 

 cidal substances. No method of systematic immunization has 

 been developed, nor does the slight pathogenicity of the organism 

 make this advisable. 



Bacteriological Diagnosis. The organism can be recognizeji 

 certainly from tissues only by isolation and morphological examina- 

 tion. Its gram-positive staining characters, lack of motility, and 

 the difficulty with which spores may be demonstrated are charac- 

 teristic. 



Transmission. The organism probably gains entrance to the 

 body through wounds or invades the tissues after death from the 

 intestines. 



Bacillus botulinus 



Disease Produced. Meat- or sausage-poisoning in man, 

 botulism (botulus = sausage). 



Van Ermengem, in 1896, isolated an organism from sausage, 

 which he believed to be the cause of poisoning. The organism has 

 since that time been several times isolated, and is, therefore, of 

 some hygienic importance, particularly in meat inspection and in 

 meat hygiene. This disease or poisoning should not be confused 

 with that produced by the Badllus enteritidis, which has already 

 been discussed. 



Distribution. Only a few well-authenticated reports of the 

 isolation of the organism are on record, and these principally 

 from European countries. 



Morphology and Staining. Bacillus botulinus is a large bacil- 

 lus, with usually rounded ends, 0.9 to 1.2 by 4 to 6 p. It is com- 

 monly single or in pairs, sometimes in short chains. Involution 

 forms frequently occur. It is motile by means of four to eight 



