504 PATHOGENIC MICROORGANISMS 



They are not easily stained, and though less resistant in this respect 

 than the tubercle bacillus, they yet belong distinctly to the group of 

 acid-fast bacilli. Once stained by the stronger dyes, such as carbol- 

 fuchsin or anilin-water-gentian-violet, they are tenacious of the dye, 

 though less so than tubercle bacilli. 



The identification of the smegma bacillus by staining methods has 

 become of great practical importance since Fraenkel,^ Miiller,^ and 

 others have demonstrated the occasional presence of acid-fast bacilli, 

 probably of the smegma group, in sputum, and in secretions from the 

 tonsillar crypts and throat. The methods of differentiation which have 

 been found most practical are those which depend upon differences in 

 the retention of stain shown by these bacilli. While it may be stated 

 as a general rule that the smegma bacilli are more easily decolor- 

 ized than tubercle bacilli, it is nevertheless important that a con- 

 trol, as suggested by Wood, be made with known tubercle bacilli 

 whenever a slide of suspected smegma bacilli is examined. For 

 the actual differentiation an excellent method is that of Pappenheim, 

 described in detail in the section on Staining, page 106. This method 

 depends upon the fact that prolonged treatment with alcohol and rosolic 

 acid decolorizes the smegma bacilli but not the tubercle bacilli. 

 Coles ' has stated that smegma bacilli will resist Pappenheim's 

 decolorizing agent for four hours at the most, while tubercle bacilli 

 will retain <the stain, in spite of such treatment, for as long as twenty- 

 four hours. 



Although minor differences between the smegma bacillus and that 

 of Lustgarten have been upheld by Doutrelepont * and others, never- 

 theless, the etiological significance of Lustgarten's bacillus in syphilis 

 has been finally discredited, and, if not identical with the smegma 

 bacillus, it at least belongs to the same group. 



The smegma bacilli have no pathogenic significance. They are 

 found upon human beings as harmless saprophytes, and all attempts to 

 infect animals have so far been unsuccessful. They are cultivated 

 with great difficulty, first cultivations from man being successful only 

 upon the richer media containing human serum or hydrocele fluid. 

 After prolonged cultivation upon artificial media they may be kept 

 alive upon glucose agar or ascitic agar. Their growth is slow; 



^Fraenkel, Berl. klin. Woch., 1898. 



2 Muller, Deut. med. Woch., 1898. 



s Coles, Jour, of State Med., 1904. 



* Doutrelepont, quoted from Klemperer, loo. clt. 



