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Polymyxins are still used mainly in treating infections caused by carbapenem-resistant Klebsiella pneumoniae worldwide. The most frequent mechanism of acquired resistance to polymyxins in Gram-negative bacilli is the occurrence of mutations in chromosomal genes regulating operons responsible for lipopolysaccharide modification. As we observed at Santa Casa de São Paulo hospital the occurrence of infections caused by isolates resistant to polymyxins in patients previously treated with this antimicrobial, and new infections caused by the same polymyxin-susceptible species, in this study, we aimed to determine the clonality of consecutive K. pneumoniae isolates from the same patients and characterize the molecular determinants of polymyxin resistance in paired or clonal isolates. A total of 24 pairs and one trio of K. pneumoniae isolates were included in this study. Species identification was achieved by mass spectrometry and multiplex PCR. Polymyxin B minimal inhibitory concentrations were determined by broth microdilution. Clonality was evaluated using pulsed-field gel electrophoresis. The presence of insertions in mgrB gene was tested by PCR, and mutations on pmrA, pmrB, phoP, and phoQ were evaluated by PCR and complete nucleotide sequencing. A fraction of 23.8% of strains resistant to polymyxin B had an insertion in mgrB. Amino acid substitution F204L in PmrB may be implicated in polymyxin resistance. Substitutions T246A and R256G in PmrB were not implicated in polymyxin resistance. In this study, polymyxin resistance after a first susceptible isolate was detected was most frequently due to an infection caused by a distinct clone.

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OBJECTIVE: To compare the antimicrobial effect in vitro of a short-chain cyanoacrylate with a long-chain cyanoacrylate (Dermabond, Ethicon, Johnson and Johnson, USA) against bacterial strains. METHODS AND ANALYSIS: The following bacterial strains were analysed: Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa. For each microorganism, standardised sterile discs (6 mm) containing 10 µL of ethyl-cyanoacrylate and 2-octyl cyanoacrylate were applied to the plate. All plates received a blank filter-paper disc with no adhesive (control). All plates were incubated for 24 hours, after which the bacterial inhibitory halos, if present, were measured in millimetres in its greater length. RESULTS: Inhibitory halos were observed for both adhesives for S. aureus. Inhibition halos were observed only for ethyl-cyanoacrylate for K. pneumoniae and E. coli. No inhibition halo was observed for P. aeruginosa in any sample. The relationship between the total size of the inhibition halos and the diameter of the paper filter for S. aureus was statistically significant compared with 2-octyl cyanoacrylate. CONCLUSION: Data shown conclude that ethyl-cyanoacrylate showed in vitro bacteriostatic activity for S. aureus, E. coli and K. pneumoniae. 2-Octyl cyanoacrylate showed in vitro lower bacteriostatic activity only against S. aureus when compared with ethyl-cyanoacrylate. No in vitro bactericidal activity of ethyl-cyanoacrylate or 2-octyl cyanoacrylate was observed.

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Objetivos: Avaliar a eficácia de um procedimento operacional padrão para limpeza de fresas intramedulares flexíveis, bem como o alcance da esterilidade, e evi-denciar a citotoxicidade da sujidade residual de uma fresa flexível utilizada na prática assistencial. Métodos: Fresas intramedulares flexíveis foram pesadas antes do processamento, após contaminação desafio e depois da limpeza. Elas foram contaminadas com Soil Test™, suspensão de Geobacillus stearothermophilus, na concentração de 106 UFC/mL, e farinha de osso bovino. Após processamento, as amostras foram incubadas em meio de cultura por 21 dias. A sujidade residual de uma fresa utilizada na prática foi submetida ao teste de citotoxicidade in vitro. Resultados: As amostras, embora esterilizadas, apontaram acúmulo de sujidade e o processamento foi ineficaz. A sujidade residual apresentou efeito citotóxico. Conclusão: Recomenda-se que o design flexível das fresas seja descontinuado pela insegurança no processamento.

Objectives: To assess the efficacy of a standard operational procedure to clean flexible intramedullary bone reamers, as well as the sterilization level, and to show the cytotoxicity of the residual dirtiness of a flexible reamer used in care practice. Methods: Flexible intramedullary bone reamers were weighed before processing, after challenge contamination and after cleaning. They were contaminated with the Soil Test™, Geobacillus stearothermo-philus suspension, in the concentration of 106 cfu/ml, and bovine bone flour. After processing, the samples were inoculated into a culture medium and incubated for 21 days. Residual dirtiness of a flexible intramedullary bone reamer used in practice was submitted to in vitro cytotoxicity test. Results: Despite being sterilized, the samples indicate to accumulated dirtiness and the processing was inefficient. Residual dirtiness presented a cytotoxic effect. Conclusion: It is recommended that the flexible design of reamers is discontinued by the lack of safety of reprocessing.

Objetivos: Evaluar la eficacia de un procedimiento operacional estándar para limpieza de fresas intramedulares flexibles, así como el alcance de la esterilidad, y evidenciar la citotoxicidad de la suciedad residual de una fresa flexible utilizada en la práctica asistencial. Métodos: Fresas intramedulares flexibles fueron pesadas antes del procesamiento, tras contaminación desafío y después de la limpieza. Fueron contaminadas con Soil Test™, suspensión de Geobacillus stearothermophilus, en la concentración de 106 UFC/mL, y harina de hueso bovino. Tras el procesamiento, las muestras fueron incuba-das en medio de cultura por 21 días. La suciedad residual de una fresa utilizada en la práctica fue sometida al test de citotoxicidad in vitro. Resultados: Las muestras, aunque esterilizadas, apuntaron acumulación de suciedad y el procesamiento fue ineficaz. La suciedad residual presentó efecto citotóxico. Conclusión: Se recomienda que el design flexible de las fresas sea descontinuado por la inseguridad en el procesamiento.

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Este estudo avaliou a atividade antibacteriana de extratos de plantas contra as cepas de Staphylococcus aureus por meio de testes de Disco-Difusão e de Concentração Bactericida Mínima (CBM). Foi testada a susceptibilidade de 52 cepas de S. aureus aos extratos hidroetanólicos das plantas: (1) Psidium guajavavar. pomifera; (2) Hymenaea courbaril var. stilbocarpa; (3) Pothomorphe umbellata; (5) Bidens pilosa, seguindo-se a metodologia baseada nas normas internacionais do CLSI. Na comparação dos resultados da ação dos extratos nas concentrações preparadas neste modelo experimental, foi observado que: B. pilosa apresentou menor ação; P. guajava var. pomifera, P. umbellata, com resultados muito próximos entre si, apresentaram ações medianas; H. courbaril var. stilbocarpa demonstrou ação muito superior aos outros extratos e ao controle com etanol. A ação in vitro dos extratos testados evidenciou a presença de princípios ativos antibacterianos. O estudo tornou evidente que os extratos hidroetanólicos das plantas 1, 2, 3 e 5 possuem ação antibacteriana in vitro contra Staphylococcus aureus MRSA e MSSA. (AU)

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Este estudo avaliou a atividade antibacteriana de extratos de plantas contra as cepas de Staphylococcus aureus por meio de testes de Disco-Difusão e de Concentração Bactericida Mínima (CBM). Foi testada a susceptibilidade de 52 cepas de S. aureus aos extratos hidroetanólicos das plantas: (1) Psidium guajavavar. pomifera; (2) Hymenaea courbaril var. stilbocarpa; (3) Pothomorphe umbellata; (5) Bidens pilosa, seguindo-se a metodologia baseada nas normas internacionais do CLSI. Na comparação dos resultados da ação dos extratos nas concentrações preparadas neste modelo experimental, foi observado que: B. pilosa apresentou menor ação; P. guajava var. pomifera, P. umbellata, com resultados muito próximos entre si, apresentaram ações medianas; H. courbaril var. stilbocarpa demonstrou ação muito superior aos outros extratos e ao controle com etanol. A ação in vitro dos extratos testados evidenciou a presença de princípios ativos antibacterianos. O estudo tornou evidente que os extratos hidroetanólicos das plantas 1, 2, 3 e 5 possuem ação antibacteriana in vitro contra Staphylococcus aureus MRSA e MSSA.

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Staphylococcus aureus (S. aureus) is one of the most frequent causes of hospital acquired infections. With the increase in multiple drug resistant strains, natural products such as propolis are a stratagem for new product discovery. The aims of this study were: to determine the in vitro antimicrobial activity of an ethanol extract of propolis; to define the MIC50 and MIC90 (Minimal Inhibitory Concentration - MIC) against 210 strains of S. aureus; to characterize a crude sample of propolis and the respective ethanol extract as to the presence of predetermined chemical markers. The agar dilution method was used to define the MIC and the high performance liquid chromatography (HPLC) method was used to characterize the samples of propolis. MIC results ranged from 710 to 2,850 µg/mL. The MIC50 and MIC90 for the 210 strains as well as the individual analysis of American Type Culture Collection (ATCC) strains of Methicillin-susceptible Staphylococcus aureus (MSSA) and Methicillin-resistant Staphylococcus aureus (MRSA) were both 1,420 µg/mL. Based on the chromatographic analysis of the crude sample and ethanol extracted propolis, it was concluded that propolis was a mixture of the BRP (SP/MG) and BRP (PR) types. The results obtained confirm an antimicrobial activity in relation to the strains of the S. aureus tested.

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The ozone is effective against most microorganisms due to its high oxidant power. Low concentrations and short-term contact are sufficient to inactivate bacteria, mold, yeast, parasites, seaweeds, protozoa and fungi. Microsporum canis is an important agent of dermatophitosis in human and animal. The aim of the current study was to assess the efficacy of ozonized oil over Microsporum canis in rabbits. Eighteen male New Zealand white rabbits, weight ranging from 2 to 3.2 kg were depilated in the cranial dorso-lateral and right caudal, and cranial and left caudal regions. The regions were inoculated with Microsporum canis, excepting the right caudal region, and were denominated TM, O, OM and M, respectively. After seven days, the treatment of lesions in TM began with 0.12g of terbinaphine 1 percent cream; in OM and O with 0.12g of ozonized oil; all animals were treated once a day for 28 days. Region M was not treated. Material was collected from those regions for cultivation in Sabouraud agar at day 28 of treatment. In the evolution of the treatment with terbinaphine, of 14 contaminated regions with Microsporum canis ten evolved to cure. With the ozonized oil, of 15 contaminations, four were cured. Clinically, that is, the macroscopic evaluation of lesions showed improvement in the TM and OM treated regions. We can conclude that there was statistical evidence of the protection action of the oil against the dermatophyte.

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The ozone is effective against most microorganisms due to its high oxidant power. Low concentrations and short-term contact are sufficient to inactivate bacteria, mold, yeast, parasites, seaweeds, protozoa and fungi. Microsporum canis is an important agent of dermatophitosis in human and animal. The aim of the current study was to assess the efficacy of ozonized oil over Microsporum canis in rabbits. Eighteen male New Zealand white rabbits, weight ranging from 2 to 3.2 kg were depilated in the cranial dorso-lateral and right caudal, and cranial and left caudal regions. The regions were inoculated with Microsporum canis, excepting the right caudal region, and were denominated TM, O, OM and M, respectively. After seven days, the treatment of lesions in TM began with 0.12g of terbinaphine 1% cream; in OM and O with 0.12g of ozonized oil; all animals were treated once a day for 28 days. Region M was not treated. Material was collected from those regions for cultivation in Sabouraud agar at day 28 of treatment. In the evolution of the treatment with terbinaphine, of 14 contaminated regions with Microsporum canis ten evolved to cure. With the ozonized oil, of 15 contaminations, four were cured. Clinically, that is, the macroscopic evaluation of lesions showed improvement in the TM and OM treated regions. We can conclude that there was statistical evidence of the protection action of the oil against the dermatophyte.

RESUMO

Staphylococcus aureus (S. aureus) is one of the most frequent causes of hospital acquired infections. With the increase in multiple drug resistant strains, natural products such as propolis are a stratagem for new product discovery. The aims of this study were: to determine the in vitro antimicrobial activity of an ethanol extract of propolis; to define the MIC50 and MIC90 (Minimal Inhibitory Concentration - MIC) against 210 strains of S. aureus; to characterize a crude sample of propolis and the respective ethanol extract as to the presence of predetermined chemical markers. The agar dilution method was used to define the MIC and the high performance liquid chromatography (HPLC) method was used to characterize the samples of propolis. MIC results ranged from 710 to 2,850 µg/mL. The MIC50 and MIC90 for the 210 strains as well as the individual analysis of American Type Culture Collection (ATCC) strains of Methicillin-susceptible Staphylococcus aureus (MSSA) and Methicillin-resistant Staphylococcus aureus (MRSA) were both 1,420 µg/mL. Based on the chromatographic analysis of the crude sample and ethanol extracted propolis, it was concluded that propolis was a mixture of the BRP (SP/MG) and BRP (PR) types. The results obtained confirm an antimicrobial activity in relation to the strains of the S. aureus tested.

RESUMO

BACKGROUND: Because of advances in technology, the number of orthopedic surgeries, mainly hip and knee replacement surgeries, has increased, with a total of 150,000 prosthetic surgeries estimated per year in the United States and 400,000 worldwide. METHODS: We used an exploratory cross-sectional study, with a quantitative approach to determine the microbial load in instruments used in orthopedic surgeries, quantifying and identifying the microbial growth genus and species, according to the surgical potential of contamination that characterizes the challenge faced by the Material and Sterilization Center at the Institute of Orthopedics and Traumatology of Hospital das Clinicas of the School of Medicine of the University of Sao Paulo, Brazil.The orthopedic surgical instruments were immersed, after their use, in sterilized distilled water, sonicated in an ultrasonic washer, and posteriorly agitated. Subsequently, the wash was filtrated through a 0.45-mum membrane and incubated in aerobic and anaerobic mediums and in medium for fungi and yeasts. RESULTS: In clean surgeries, 47% of the instruments were contaminated; in contaminated surgeries, 70%; and, in infected surgeries, 80%. Regardless of the contamination potential of the surgeries, the highest quantitative incidence of microorganism recovery was located in the 1 to 100 colony-forming unit range, and 13 samples presented a microbial growth potential >300 colony-forming units. Regardless of the contamination potential of the surgeries, there was a convergence in the incidence of negative-coagulase Staphylococcus growth (28%, clean surgeries; 32%, contaminated surgeries; and 29%, infected surgeries) and Staphylococcus aureus (28%, contaminated surgeries; and 43%, infected surgeries). CONCLUSION: Most of the microorganisms recovered from the analyzed instruments (78%) were vegetative bacteria that presented their death curve at around 80 degrees C, characterizing a low challenge considering the processes of cleaning and sterilization currently employed by the Material and Sterilization Center. Fewer microorganisms were recovered from instruments used in clean surgeries in comparison with those used in contaminated and infected surgeries.

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