Comparative Study on Bacteriostatic Action of Sulfanilamide,Sulfapyridine,Sulfanilyl-Sulfanilamide and Sulfathiazol upon Enterococci

At the present time it is not as yet possible to predict from the chemical composition of various sulfanilamide derivatives their chemotherapeutic activity toward different microorganisms that are more or less susceptible to the action of sulfanilamide. Thus, it is necessary to test the efficacy of new compounds both in vitro and in vivo. It is generally agreed that sulfanilamide in therapeutic doses has little or no effect on enterococci. Recently Helmholz¹ reported that sulfathiazol and sulfamethylthiazol in urine are bactericidal toward enterococci. Hill² found that sulfanilamide, sulfapyridine and sulfathiazol in a concentration of 100 mg % have a marked bacteriostatic or germicidal action upon relatively small numbers of alpha-Streptococcus fecalis in urine. This author made the important observation that sulfathiazol as present in urine after administration of the drug exerts greater bacteriostatic activity than the same amount added to normal voided urine. Long and Bliss³ observed that sulfanilamide, sulfapyridine and sulfathiazol in concentrations of 10 mg % only slightly inhibited the growth of hemo-lytic streptococcus zymogenes (Group D) in beef infusion, 2% Neo-peptone, 0.075% dextrose broth. Clinically, Pool and Cook⁴ reported sterilization of urine of patients harboring Streptococcus fecalis following the administration of sulfathiazol and sulfamethylthiazol, respectively. The concentration of the drug in the urine of these cases exceeded 150 mg %. The following in vitro experiments were carried out in order to determine the relative bacteriostatic activity of various sulfanilamide derivatives toward hemolytic and non-hemolytic enterococci.

As culture medium 1/4% maltose phenol red broth base (Difco), containing tryptose (1%), sodium chloride (0.5%), dipotassium phosphate (0.1%), and phenol red, was used. Sulfanilamide, sulfapyridine, sulfanilyl-sulfanilamide (Disulon), sulfathiazol (2-sulfanilamidothiazol) and sulfamethylthiazol (2-sulfanilamidomethyl-thiazol) were added to this culture medium.