FATE OF TUBERCLE BACILLI Orrsim: TIIK ANIMAL BODY 



317 



TABLE; 10 SUMMARY OK THE RESULTS KKOM EXPOSING TUBUKCLK BACILLI 



TO DIRECT SUNSHIKK 



PURPOSE 

 OF WORK 



EFFECT OF DESICCATION UPON BACTERIA 



The P lir P oses f tms work was to compare theef- 

 feet of desiccation upon tubercle bacilli with that 

 upon some nonacid-fast bacteria. Two types of 

 tubercle bacilli were used, human and bovine. The nonacid-fast 

 organisms used were two pathogenic organisms, B. typhosus and 

 B. diphtheria, and of the nonpathogenic germs sporebearing and 

 nonspore-bearing were used (see list in Table n). . 



CULTURES AND cu ^ures were grown and the emulsions made 



EMULSIONS in the same way as described in the section on the. 

 effect of light upon bacteria. Only fresh, active 

 cultures were used. The tubercle bacilli were grown only upon 

 glycerine egg. 



MANNER OF 

 EXPOSURE 



marmer f preparing the organisms for ex- 

 posure was also the same as that described in the 

 last section, with the exception that the smears 

 were made only upon sterile glazed paper slips. These smeared 

 slips were exposed in a dark sheet-iron box that was well ventilated. 

 Control slips of all the organisms tested were seeded a few minutes 

 after the visible moisture had disappeared from the paper slips. 

 Thereafter duplicate slips were seeded at the end of 12 hours and 

 i, 2, 4, 8, 12, and 16 days. The tubercle bacilli were cultivated 

 upon glycerine egg at 38 C. for six weeks. In examining the cul- 

 tures for growth of these germs it is necessary to scrape the surface 

 and make stained preparations even when visible growth is not 

 present, for in practically every case there will be one or two cul- 

 tures between the evidently visible growth and the culture proven 

 to contain no growth by the absence of organisms in stained pre- 

 parations, in which the cultures will have only a few, usually in- 

 visible, colonies. This condition was not noted in the cultures 

 from smears exposed to the sun. 



The smears of B. diphtheria were cultivated upon Loeffler's 

 blood serum at 37 C., and those of all other organisms were placed 

 in broth and cultivated at the optimum temperature for each species. 



