To the Editor.—The validity of in vitro evaluation of the sensitivity of microorganisms to sulfonamide compounds has long been questioned because of the minimal inoculum and minimal media that must be used and because of bacteriostatic nature of the drug. Recently, sulfadiazine compounds of zinc and silver have been reported to be effective topical therapeutic agents for Pseudomonas infection of burns.1.2 Further, it has been indicated2 that the growth of P aeruginosa was inhibited by as low a concentration as 0.05 μM of sulfadiazine silver and 0.025 μM of sulfadiazine zinc per millimeter of nutrient broth. On the other hand, the concentration of the drug inhibitory for Klebsiella, Escherichia coli, and Staphylococcus were 0.025, 0.25 and 0.05 μM/ml of nutrient broth, respectively.
The marked activity reported of these compounds prompted us to study the in vitro sensitivity of a variety of organisms to sulfadiazine silver and sulfadiazine
NAGESHA CN, SAGAR IK. In Vitro Activity of Sulfadiazine Compounds of Zinc and Silver. Arch Surg. 1978;113(7):906. doi:10.1001/archsurg.1978.01370190128033