RESUMO
OBJECTIVE: To evaluate the efficacy of the AbTox Plazlyte Sterilization System against selected microbial species using inoculated carriers and surgical instruments. SETTING: The microbiology laboratory of a 700-bed adult tertiary-care hospital. DESIGN: The study was conducted in two phases. In phase 1, microorganisms were inoculated to various metal, paper, plastic, and glass carriers, as well as surgical equipment, and processed in cycle II of the AbTox sterilizer. Phase 2 compared AbTox cycle III with ethylene oxide sterilization using stainless steel washers, penicylinders, and surgical equipment. In both phases, cultures of equipment and carriers were obtained after processing. The phenotypic profiles and antibiograms of positive cultures were compared to the original inoculate to rule out the possibility of contamination. RESULTS: Of a total of 350 paper carriers, 375 metal washers, and 234 pieces of equipment processed in cycle II and using trypticase soy broth as the inoculating medium, 123 metal washers (32%) and 8 instruments (3%) failed to be sterilized. Similar failures were noted with cycle III. The presence of either salt or protein adversely affected the system's ability to sterilize in either cycle. CONCLUSION: Further studies are needed to evaluate the extent to which salt or organic material compromise low-temperature gas-plasma sterilization. Meanwhile, users should exercise caution and use care in the cleaning of instruments that will be processed in the plasma-based sterilization technologies.
