BACILLUS MALLEI AND MISCfiLLAiSTEOUS BACILLI 357 



occurs rather frequently in market milk. It is not known to infect 

 man. 



Bacillus (Bacteriiim) Acne.— This minute non-motile organ- 

 ism, first described by Gilchrist, is constantly present in the pap- 

 , ules and pustules of the common skin affection, acne vulgaris. 

 Cultures are most readily obtained by expressing, with careful 

 asepsis, some of the cheesy pus from a recent papule and mixing 

 it with 2 c.c. of ascitic fluid in a test-tube. Dilutions from this 

 are made to similar amounts of ascitic fluid in series (about five 

 tubes in all). To the first tube one adds 8 c.c. of sterile glucose 

 broth and covers this with a layer of paraffin oil (albolene) . To each 

 of the remaining tubes are then added 8 c.c. of melted glucose 

 agar cooled to 50° C, the contents of each tube mixed without 

 introducing air bubbles and then quickly solidified by immersion 

 in cold water. The colonies of B. acne develop at 37° C. after 

 five to ten days, beginning about 8 mm. beneath the surface, and 

 they grow best in a narrow zone about 5 mm. in depth. The 

 colonies attain a large size (3 mm.) and an abundant supply 

 of bacillary substance for preparation of vaccine may be obtained 

 by thrusting a sterile glass capillary into such a colony. In 

 its behavior to oxygen when first isolated the organism exhibits • 

 the same peculiarity as the bacillus mentioned in the preceding 

 paragraph. 



Sometimes the agar cultures fail. In that event one may 

 , repeat the series of ascitic-glucose-agar dilution cultures by 

 inoculating with sediment from the ascitic-broth tube, which has 

 been incubated ten days. This broth culture usually develops 

 an abimdant growth of staphylococci for the first few days but 

 after ten days the cocci will have disintegrated to a considerable 

 extent and B. acne will usually have become the most numerous 

 organism in the sediment. ^ ' 



Bacillus Fusiformis (Vincenti). — In an ulcerative disease of 

 the tonsils, known as Vincent's angina there occur very large 

 numbers of fusiform rods, 0.3 to 0.8/x in thickness and 3 to lo^ long, 

 associated with spiral filaments with rather coarse windings. 



