98 STUDY AND IDENTIFICATION OF BACTERIA 



# 



2. The leprosy bacilli stain more solidly and when granules are pres- 

 ent they are coarser and more widely separated than the fine granula- 

 tions of the tubercle bacillus. 



3. They do not stand decolorization quite as well as the tubercle 

 bacillus. With 20% sulphuric acid in water they hold their color almost 

 as well as tubercle bacilli but with 3% HCL in alcohol they decolorize 

 in about two hours as against twelve to twenty-four hours for the 

 tubercle bacillus. 



4. Leprosy bacilli have neither been surely cultivated nor surely 

 inoculated with pathogenic results into guinea-pigs or other experi- 

 mental animals and it is by the negative results upon cultivating or 

 animal inoculation that we have our surest method of differentiation 

 from tubercle bacilli. 



Leprosy bacilli are chiefly spread through the lymphatics, but in nodular leprosy, 

 their occurrence in the blood stream during the febrile accessions is so constant that 

 this route may also be of importance. Next to the corium they are most abundant 

 in the lymphatic glands. They stain readily by Gram's method. 



A great amount of work has been done within recent years in attempting to 

 cultivate the leprosy bacillus. 



In 1900 Kedrowsky, culturing material from 3 cases of leprosy obtained diph- 

 theroids from 2 and a streptothrix from i. A rabbit was inoculated first in- 

 travenously and later intraperitoneally with this nonacid-fast streptothrix and 

 when killed six months later showed peritoneal nodules from which both diphtheroids 

 and acid-fast bacilli, but not a streptothrix, were recovered culturally. Injection of 

 cultures of the acid-fast bacilli and diphtheroids into rabbits and mice produced 

 nodules which, when cultured, showed acid-fast organism or diphtheroids. In 

 1901, he cultivated a diphtheroid from a fourth case of leprosy. 



Fraser and Fletcher working with Kedrowsky's culture produced peritoneal 

 nodules with the killed as well as the living organism. They were able to produce 

 the same results with B . phlei. 



With emulsions of leprous nodules, rich in leprosy bacilli, they could not produce 

 similar lesions in the experimental guinea-pigs. 



Rost obtained a culture on a salt-free medium from which he prepared his leprolin 

 by a process similar to that used for old tuberculin. It was claimed that leprolin 

 had marked curvative power in leprosy. Recently Williams and Rost have culti- 

 vated a streptothrix on a medium containing milk. 



Clegg, by inoculating his medium with cultural amoebae, obtained growth of 

 diphtheroid organism, with acid-fast tendencies, from the spleen pulp of lepers. 



Duval, by using media containing amino-acids, as result of tryptic digestion, 

 brought forward two organisms, one of which was a diphtheroid and grew luxuriantly 

 while the other showed a slow scanty growth and was acid-fast. 



Bayon, by using placental media, isolated an organism rather resembling that 

 of Kedrowsky. These organisms alone responded to immunity tests when si 



