Efeitos da Sulfadiazina de prata em feridas cirúrgicas experimentalmente induzidas em camundongos isogênicos BALB/c. Aspectos morfológicos, microbiológicos, imunológicos e hematológicos

Abstract

Silver sulfadiazine (SDP) is an water-insoluble bacteriostatic sulfonamide. Staphyloccus aureus, Escherichia coli, Pseudomonas aeruginosa, some Proteus and Enterobacteriaceae strains and Candida albicans are often responsive to SDP. After beginning the SDP use in bum wounds, it has emerged resistance to sulfonamides, mainly among Enterobacteriae. It was reported an enhancing effect in the rate of reepithelialization by SDP and its vehicle. Leukopenia is an associated complication with th is medicine. It has been described in vitro citotoxicity caused by SDP. It was intended to analyze and compare the effect from silver sulfadiazine in cream Lanette (CL) (SDP/CL; A group), to CL (B group) and without medicine (C group) on the skin wounds measuring 2x2 cm, induced experimentally, on the back dorsum from isogenic BALB/c mice, male, at age of twelve weeks (ten animais per group). The hair loss observed around wounds, on the A and B groups, was transient, probably by the synergistic effects from SDP citotoxicity and the CL’s compounds, methyl and propylparaben. The wounds were whole closed at 22th, 28th e 31st PO, for C, B and A groups, respectively. The semi quantitative evaluation in the granulation tissue and collagendeposition, the morphometric studies from the vessels, fibroblasts and neutrophils did not indicate that SDP accelerated the wound healing. The epithelialization was faster inthe C group, followed by B group. The seeding of the harvested sampling from the wounds in the culture médium agar-blood, eosin methylene blue and Sabouraud agar, at 37°C for 48 hr, revealed that Staphylococcus saprophyticus were predominant in the animal’s wound from groups A and C. The Citrobacter diversus and Klebsiella spp were predominant in the animal wounds in group B. The resistance and sensitivity profiles from these bactéria were similar in the same detected species from animais of groups A, B and C. The filtered SDP did not inhibit the Staphylococcus aureus ATCC 29213 growths, in the liquid médium, on the concentration used. The minimum inhibitory concentration of unfiltered SDP for Escherichia coliATCC 25922 was 128 pg/ml in this assay. The medicine used, SDP and/or CL, on the mice's wounds did not interfered on the circulating leukocyte population. The assays from cultured bone marrow cells shown low viability of the cells exposed to unfiltered SDP on concentrations from 25 to 250pg/ml, due to toxicity of this drug. It was investigated in vitro IL-4 and nitric oxide production, by sandwich ELISA and Griess methods, respectively; these elements were not detected probably because of the sensibility limits of the assays or the immaturity of the cells. It can be concluded that other medicine may be analyzed by using the experimental design described in the present study. Also, new/n vitro studies are necessary in order to observe the effect of Lanette's components, particularly on wounds from human and murine hair and keratinocytes.