Objective: To evaluate the efficacy of a disinfectant based on hydrogen peroxide. Methods:The method used to assess the efficacy of the disinfectant was the agar plate technique. With this procedure, it was possible to determine the percentage of inhibition of the high-level disinfectant of STERIS against four microorganisms, i.e., Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus (Beta-Hemolytic 227), Salmonella choleraesuis (Kuznedorf CMDM 074), and Bacillus subtilis (ATCC 6633). The effectiveness of five disinfectant concentrations (0.02%, 0.04%, 0.08%, 1%, and 2%) was determined and evaluated in three different times 5, 10, and 15 min, for vegetative strains and 3, 6, and 9 h for the sporulated strain. Results:According to the experimental test, the reduction of the microbial population was, on average, 100% for the disinfectant concentrations of 0.08%, 1%, and 2%. Conclusion:The results obtained demonstrated that the high-level disinfectant of STERIS based on hydrogen peroxide is 100% effective when the concentration recommended by the commercial house (2%) is used in the shortest time exposure to disinfectant. The minimum level of effectiveness was 0.08%; however, if lower concentrations are used, destruction of the microorganisms is not guaranteed.

Abstract. In the present work, the evaluation of the antimicrobial activity of Diplostephium phylicoides and Diplostephium revolutum on different microorganisms was carried out on using bacteria such as Escherichia coli (CMPUJ:034), Staphylococcus aureus (CMPUJ:370), Salmonella typhi (CMPUJ:045) and Pseudomonas aeruginosa (CMPUJ:065), yeasts such as Saccharomyces cerevisiae (CMPUJ:H042) and Candida albicans (CMPUJ:H022), and filamentous fungi such as Penicillium chrysogenum (CMPUJ:H061) and Aspergillus niger (CMPUJ:H002). This assessment was made by the method of plates and wells using extracts from the leaves of the previously mentioned plants. The extracts were made with different solvents, ethanol, ethyl acetate, dichloromethane and petroleum ether. The results showed that the ethyl acetate extract of Diplostephium phylicoides has antimicrobial activity against Staphylococcus aureus and Candida albicans; furthermore, the dichloromethane extract showed an inhibitory effect against Saccharomyces cerevisiae. When comparing the extracts of the two plants, under the evaluated conditions, the extracts presented antimicrobial activity, and the ethyl acetate extract of Diplostephium revolutum the one that showed better activity against all the microorganisms.

Objective: The objective of the study was to determine the antimicrobial activity of leaf and flower extract in Chromolaena scabra (L. f.) R.M. King and H. Rob., against selected strains of bacteria and fungi. Methods: The agar diffusion method with plate perforation was developed; the microorganisms used were strains of Staphylococcus aureus and Escherichia coli, Aspergillus niger, and Penicillium digitatum. Rifampicin was used as a positive control. The evaluation was performed by measuring the diameter of the growth inhibition zones around the holes. The inhibitory effect of the plant extracts was obtained by its efficiency compared to the positive control. A comparison with fluconazole and ketoconazole was performed to determine how much of the extract is required to cause inhibition of fungal growth from the standard. Results: IC50 was determined by relating the ln of mass evaluated with respect to the square of the inhibition halo; ethanolic extracts of leaves and flowers of petroleum ether with IC50 values of 85.8 mg/ml and 50.3 mg/ml showed the highest inhibitory effect against S. aureus; the extract of petroleum ether and ethanol from leaves with IC50 of 64 mg/ml and 60 mg/ml, respectively. They were effective with A. niger. Leaf petroleum ether extract showed the best relative antifungal activity against A. niger with respect to fluconazole equivalent to 459.51 when fluconazole is 1.0. Conclusion: The extracts with high potential to inhibit the growth of microorganisms were determined to be ether flowers of petroleum and ethanol leaf extracts.

Objective: To evaluate the bactericidal activity of an antiseptic gel for hygiene and disinfection of the hands by rubbing. Methods: The dilution-neutralization method was used according to Colombian Technical Standard NTC, 2009, 12, 16 in Instituto Colombiano de Normas Técnicas y Certificación (ICONTEC), 5 strains, over 6 different types and with 6 replicas per time were exposed to the antiseptic gel, using Letheen Broth as a neutralizer substance. Results: A 99% of reduction was obtained with Staphylococcus aureus 6538, Enterococos hirae 10541, Pseudomonas aeruginosa 15442 and Klebsiella sp, within the first 30 s of exposure to the gel and within the first 60 s of exposure using the Escherichia coli 19538. All strains used coming from American Type Culture Collection (ATCC). Conclusion: It was confirmed that the product is effective. In presence of a neutralizer substance, the microorganisms were not inhibit, so the growing reduction occurs due to the action of the product.