ACID-FAST BACILLI OTHER THAN BACILLUS TUBERCULOSIS 469 



occasionally isolated from water, grass or manure, and they are also 

 found in association with man and the higher domestic animals, 

 frequently occurring as parasites upon the skin, less commonly in 

 the nasal secretion or sputum. 



Morphologically the acid-fast bacteria of the non-pathogenic type 

 are somewhat shorter and relatively thicker than the tubercle bacillus 

 (human type), and in culture they not infrequently grow in filaments 

 and exhibit branching. Upon artificial media, furthermore, develop- 

 ment is relatively rapid; growth usually appears within forty-eight 

 hours, even at 25 to 27 C. The usual type of growth is an irregular, 

 wrinkled layer, waxy in appearance and of variable color from gray 

 to yellow, orange or even brown. 1 The injection of considerable 

 amounts of the bacteria into guinea-pigs may lead to the formation 

 of granulation tissue nodules, for the organisms are very insoluble in 

 the body juices; superficially these nodules may resemble tubercles, 

 but they differ in two important particulars they do not develop 

 progressively but are limited to the site of inoculation, and they tend 

 to soften gradually and eventually to suppurate and heal spon- 

 taneously with scar tissue formation. 



The best-known members of the group are: Bacillus phlei, includ- 

 ing the various bacilli isolated from grasses and manure; the smegma 

 bacillus, which grows on the genitalia and the cerumen; and the 

 nasal secretion type found occasionally on the skin, in the nasal secre- 

 tion, the sputum, tonsillar exudates and rarely in gangrene of the 

 lungs. It is very probable that the tubercle bacilli of cold-blooded 

 animals (ichthic tubercle bacilli) fish, turtles, snakes, and the 

 " Blindschleiche" bacillus belong to this group. 



The Smegma Bacillus. Alvarez and Tarbel 2 found an organism 

 on the external genitalia and around the anus which is very similar 

 morphologically and in staining reaction to the tubercle bacillus. 

 Moeller 3 and others have confirmed this observation. The organism 

 was called the smegma bacillus. It has been regarded by many as 

 identical with a bacillus described in 1884 by Lustgarten as the 

 causative organism of syphilis. 



The cultivation of both of these organisms in artificial media is 

 difficult, and it is not definitely proven that it has been accomplished. 



The practical importance of these organisms lies in the fact that 



1 Tuberculin is not produced in cultures in artificial media. 



2 Arch. d. phys. norm, et path., 1885, No. 7. 



3 Centralbl. f. Bakt., Orig., 1902, xxxi, 278. 



