Sulfadiazine silver-resistant Pseudomonas in Burns. New topical agents
S. M. Modak and C. L. Fox Jr
Sulfadiazine silver-resistant strains of Pseudomonas aeruginosa isolated
from burned patients from several countries are sensitive to sulfadiazine
silver in vitro, but in burned mice and rats resist topical therapy with
sulfadiazine silver. In searching for an effective topical agent against
these resistant organisms, we found that FPQC
(1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7[1-piperazinyl]-quinoline-carboxylic
acid) and its silver salt are effective both in vitro and in vivo. In
vitro, their minimal inhibitory concentrations are ten to 20 times lower
than that of sulfadiazine silver. In burned mice infected with resistant
Pseudomonas strains, mortality in groups receiving topical therapy with
FPQC or FPQC silver is 0%, but 80% to 100% with sulfadiazine silver and
100% without treatment. Similar results were obtained in burned rats. The
efficacy of FPQC and FPQC silver in vivo may represent discovery of new
agents of known low toxicity that are useful in topical burn therapy.
