title: Stability of antimicrobial activity of peracetic acid solutions used in the final disinfection process.
abstract: The instruments and materials used in health establishments are frequently exposed to microorganism contamination, and chemical products are used before sterilization to reduce occupational infection. We evaluated the antimicrobial effectiveness, physical stability, and corrosiveness of two commercial formulations of peracetic acid on experimentally contaminated specimens. Stainless steel specimens were contaminated with Staphylococcus aureus, Escherichia coli, Candida albicans, blood, and saliva and then immersed in a ready peracetic acid solution: 2% Sekusept Aktiv (SA) or 0.25% Proxitane Alpha (PA), for different times. Then, washes of these instruments were plated in culture medium and colony-forming units counted. This procedure was repeated six times per day over 24 non-consecutive days. The corrosion capacity was assessed with the mass loss test, and the concentration of peracetic acid and pH of the solutions were measured with indicator tapes. Both SA and PA significantly eliminated microorganisms; however, the SA solution was stable for only 4 days, whereas PA remained stable throughout the experiment. The concentration of peracetic acid in the SA solutions decreased over time until the chemical was undetectable, although the pH remained at 5. The PA solution had a concentration of 500-400 mg/L and a pH of 2-3. Neither formulation induced corrosion and both reduced the number of microorganisms (p = 0.0001). However, the differences observed in the performance of each product highlight the necessity of establishing a protocol for optimizing the use of each one.
authors.affiliation: Department of Dentistry, Universidade de Taubaté, Taubaté, SP, Brazil.
authors.forename: Solange Alves da Silva
authors.initials: SA
authors.lastname: Costa
authors.affiliation: Department of Biology, Universidade de Taubaté, Taubaté, SP, Brazil.
authors.forename: Olívia Ferreira Pereira de
authors.initials: OF
authors.lastname: Paula
authors.affiliation: Basic Bioscience Institute, Universidade de Taubaté, Taubaté, SP, Brazil.
authors.forename: Célia Regina Gonçalves E
authors.initials: CR
authors.lastname: Silva
authors.affiliation: Basic Bioscience Institute, Universidade de Taubaté, Taubaté, SP, Brazil.
authors.forename: Mariella Vieira Pereira
authors.initials: MV
authors.lastname: Leão
authors.affiliation: Basic Bioscience Institute, Universidade de Taubaté, Taubaté, SP, Brazil.
authors.forename: Silvana Soléo Ferreira dos
authors.initials: SS
authors.lastname: Santos
mesh_terms: D002176:Candida albicans / Q000187:drug effects; D015169:Colony Count, Microbial; D003343:Corrosion; D004202:Disinfectants / Q000737:chemistry / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D004355:Drug Stability; D004864:Equipment and Supplies / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D010463:Peracetic Acid / Q000737:chemistry / Q000494:pharmacology*; D015203:Reproducibility of Results; D012463:Saliva / Q000382:microbiology; D013193:Stainless Steel / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D004202:Disinfectants; D013193:Stainless Steel; D010463:Peracetic Acid