150 



ANTISEPTICS 



oxygen uptake of pneumococcus by doses which inhibited 

 growth almost completely. Kohn and Harris (1941) 

 found that a notable decrease in the respiration of Bact. 

 coll occurred only with very large doses of sulfonamides. 

 Amounts which produced a 30% retardation of growth did 

 not atfect the oxygen uptake. 



The results of Dorfman et al. (1940, 1941) with dysen- 

 tery bacteria deal almost entirely with the interaction 

 between nicotinic acid and some sulfonamides, which has 

 nothing to do with the fundamental sulfonamide effect, 

 because sulfanilamide does not show this reaction. The 

 few data which can be applied to the main problem show 

 that a much larger dose is needed to retard respiration 

 than to retard growth. Growth was retarded slightly 

 by 1 mg. in 100 cc, it was completely inhibited by 30 

 mg,, but 120 mg. were needed to produce a 15% de- 

 crease of the oxygen uptake. 



This agrees well with the extensive study by Hirsch 

 (1942). Table 31 shows some of his data. While 0.15 

 ppm. of sulfathiazole reduces the multiplication rate of 

 Bacteriu coU 75%, 255 ppm., or 1700 times the growth- 



TABLE 31 

 Effect of sulfa-thiazole on Bacterium coli. (Fi'om Hirsch, 1942.) 



