The Use of Sulfathiazole as a Urinary Antiseptic

Abstract

Helmholz determined the bacteriostatic and bactericidal activity of sulfathiazole toward bacteria commonly found in urinary infections, such as Streptococcus faecalis, Staphylococcus aureus, Escherichia coli, Aerobacter aerogenes, Proteus ammoniae and Pseudomonas aeruginosa. Urine of patients that were given 1/2 grain (0.032 g.) per lb. (0.45 kg.) per day was used. The effect of sulfathiazole in urine was tested at pH levels of 5.5, 6.5 and 7.5. Bacterial counts were done before incubation and after 24 hrs.'' incubation. A decrease in the number of bacteria was considered as evidence of bactericidal activity; an increase in the number, not exceeding 4-fold, to indicate bacteriostatic activity of the drug. Sulfathiazole in a conc. of 50 mg% in urine was bactericidal toward all strains of Staphylococus tested. At pH 5.5 sulfathiazole (6.5 mg%) was markedly less effective than at pH 6.5 and 7.5. With Pseudomonas aeruginosa 150 mg% was bactericidal at all pH levels; lower concs. were more effective at pH levels of 6.5 and 7.5 than at 5.5. Sulfathiazole is also bactericidal towards Str. faecalis, being markedly more effective at lower than at higher pH. Against this organism it is superior to sulfanilamide. At 300 mg% sulfathiazole was bactericidal at all pH levels tested. Pseudomonas aeruginosa was found to be rather resistant even at 300 mg% of sulfathiazole; only 8 of 10 observations indicated bactericidal effect. With Aerobacter aerogenes there was a slightly greater bactericidal activity with 25 mg% of sulfathiazole than with 100 mg%. At 250 mg% only 3% of the observations did not indicate either bacteriostatic or bactericidal activity. E. coli was not so successfully killed off in the lower concs. as A. aerogenes. 96% of urine specimens containing 200 mg% of sulfathiazole were bactericidal or bacteriostatic toward E. coli. Different strains of bacteria showed some variation in their susceptibility to the drug.