Bacillus Proteus Vulgaris 369 



immunity resulting from the treatment with killed cultures 

 the serum of the animal becomes agglutinative and bac- 

 tericidal ; in the immunity resulting from treatment with the 

 exotoxin, antitoxin is produced. 



BACILLUS PROTEUS VULGARIS (HA USER). 



General Characteristics. An actively motile, flagellated, non- 

 sporogenous, non-chromogenic, liquefying, aerobic and optionally 

 anaerobic, doubtfully pathogenic, aerogenic bacillus, easily cultivated 

 on artificial media and readily stained by the ordinary methods, though 

 not by Gram's method. 



This bacillus was first found by Hauser* in decomposing 

 animal infusions, usually in company with two closely allied 

 forms, Proteus mirabilis and Proteus zenkeri, which, as the 

 experiments and observations of Sanfelice and others show, 

 may be identical with it. According to Kruse, it is quite 

 probable that the mixed species formerly called Bacterium 

 termo was largely made up of the proteus. 



Distribution. The organism is a common saprophyte 

 and is very abundant in water, earth, and air. It is to be 

 expected wherever putrefactive change is in progress. It is 

 a common mistake for the novice to look upon it as a member 

 of the Bacillus coli group. 



Morphology. The bacilli are variable in size and shape 

 pleomorphic and are named proteus from this peculiarity. 

 Some differ very little from cocci, some are more like the 

 colon bacillus in shape, others form long filaments, and oc- 

 casional spirulina forms are met with. True spirals are 

 never found. All of the forms mentioned may be found in 

 pure cultures of the same organism. The diameter of the 

 bacillus is usually about 0.6 /w, but the length varies from 1.2 

 fi or less to 4 f* or more. No spores are formed. The organ- 

 isms are actively motile. The long filaments frequently form 

 loops and tangles. Flagella are present in large numbers. 

 Upon one of the long bacilli as many as one hundred have 

 been counted. Involution forms are frequent in old cultures. 



Staining. The bacilli stain well by the ordinary methods. 

 Gram's method usually fails. 



Cultivation. The proteus is easily cultivated and grows 

 well in all the artificial media. 



Colonies. Upon gelatin plates a typical phenomenon is 



*"Ueber Faulnissbakterien," Leipzig, 1885. 

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