RESUMO
Acne affects most of the world's population, causing an impact on the self-esteem of adolescents and young adults. One of the causes is the presence of the bacteria Cutibacterium acnes which are part of the natural microbiota of the skin. Topical treatments consist of anti-inflammatory and antibiotics, which could select resistant strains. Alternatives to the antibiotic are biocomposites that have antimicrobial activity like biosurfactants which are produced by bacteria. An innovative way of applying these compounds is bioadhesive polymeric films that adhere to the skin and release the active principle topically. Rhamnolipids have great potential to be used in the treatment of acne because they present antimicrobial activity against C. acnes in low and safe concentrations (MIC of 15.62 µg/mL, CBM of 31.25 µg/mL and CC50 of 181.93 µg/mL). Four films with different rhamnolipids concentrations (0.0; 0.1; 0.2; and 0.3%, w/w) were obtained as to visual appearance, mass variation, thickness, density, solubility, pH, water vapor transmission, mechanical properties (folding endurance, bioadhesion strength, tensile strength, elongation at break and Young's modulus), scanning electron microscopy and infrared. The results show that these formulations had a homogeneous appearance; elastic mechanical properties; pH similar to human skin and bioadhesive. The polymeric films containing rhamnolipids were effective against C. acnes, in the in vitro test, at the three concentrations tested, the film with the highest concentration (0.3%, w/w) being the most promising for presenting the highest antimicrobial activity. Thus, the polymeric film containing rhamnolipids has the potential to be used in the treatment of acne.
Assuntos
Glicolipídeos , Testes de Sensibilidade Microbiana , Polímeros , Glicolipídeos/química , Glicolipídeos/administração & dosagem , Glicolipídeos/farmacologia , Polímeros/química , Testes de Sensibilidade Microbiana/métodos , Antibacterianos/farmacologia , Antibacterianos/administração & dosagem , Antibacterianos/química , Administração Tópica , Propionibacterium acnes/efeitos dos fármacos , Acne Vulgar/tratamento farmacológico , Humanos , Pele/efeitos dos fármacos , Solubilidade , Anti-Infecciosos/farmacologia , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/química , Resistência à Tração , Química Farmacêutica/métodosRESUMO
Recently, considerable uncertainty has arisen concerning the appropriate susceptibility testing for cefiderocol in gram-negative bacilli, particularly in the context of its application to Acinetobacter spp. The optimal method for assessing the susceptibility levels of Acinetobacter spp. to cefiderocol remains a subject of debate due to substantial disparities observed in the values obtained through various testing procedures. This study employed four minimum inhibitory concentration (MIC) methodologies and the disk diffusion to assess the susceptibility of twenty-seven carbapenem resistant (CR)-Acinetobacter strains to cefiderocol. The results from our study reveal significant variations in the minimum inhibitory concentration (MIC) values obtained with the different methods and in the level of agreement in interpretation categories between the different MIC methods and the disk diffusion test. Among the MIC methods, there was relatively more consistency in reporting the interpretation categories. For European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, the categorical agreement (CA) for MIC methods ranged between 66.7 and 81.5%. On the other hand, the essential agreement (EA) values were as low as 18.5-29.6%. The CA between MIC methods and disk diffusion was 81.5%. These results emphasize the need for a reliable, accurate, and clinically validated methodology to effectively assess the susceptibility of Acinetobacter spp. to cefiderocol. The wide variability observed in our study highlights the importance of standardizing the susceptibility testing process for cefiderocol to ensure consistent and reliable results for clinical decision-making.
Assuntos
Acinetobacter , Antibacterianos , Cefiderocol , Cefalosporinas , Testes de Sensibilidade Microbiana , Testes de Sensibilidade Microbiana/métodos , Acinetobacter/efeitos dos fármacos , Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Humanos , Infecções por Acinetobacter/microbiologiaRESUMO
PURPOSE: To evaluate the performance of the rapid colorimetric polymyxin B microelution (RCPEm) in determining polymyxin B resistance directly from Enterobacterales-positive blood cultures. METHODS: A set volume of positive blood culture bottles (diluted 1:10) was inoculated into a glucose-broth-phenol red solution (NP solution), where a polymyxin B disk was previously eluted (final concentration of 3 µg/mL). Test was read each 1 h for up to 4 h. Color change from red/orange to yellow indicated resistant isolates. Results were compared to the reference method, broth microdilution (BMD), performed from colonies grown on solid media from the same blood culture bottle. RESULTS: One hundred fifty-two Enterobacterales-positive blood cultures were evaluated, 22.4% (34/152) of them resistant to polymyxin B (including 6.6% with borderline MICs). When performing directly from positive blood cultures (RCPEm-BC), specificity and sensitivity were 99.1% and 94.1%, respectively. Of note, 79.4% (27/34) of truly resistant isolates required 3 h of incubation, compared to the 18 ± 2 h incubation that microtiter plates of BMD demand before reading can be performed. CONCLUSIONS: RCPEm directly from blood cultures has great potential to be part of the routine of clinical microbiology laboratories to establish polymyxin B susceptibility, impacting outcome of patients with bloodstream infections caused by carbapenem-resistant Enterobacterales.
Assuntos
Antibacterianos , Hemocultura , Colorimetria , Testes de Sensibilidade Microbiana , Polimixina B , Polimixina B/farmacologia , Humanos , Colorimetria/métodos , Testes de Sensibilidade Microbiana/métodos , Antibacterianos/farmacologia , Hemocultura/métodos , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Sensibilidade e Especificidade , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/diagnóstico , Farmacorresistência Bacteriana , Bacteriemia/microbiologia , Bacteriemia/diagnósticoRESUMO
Introducción: En la actualidad las infecciones por hongos afectan entre el 20 y el 25 por ciento de la población. Objetivo: Determinar la concentración mínima inhibitoria de dos lotes de OLEOZON® almacenados a temperaturas de 5 y 30°C en envases de vidrio y polietileno de alta densidad, durante 24 meses como parte del estudio de estabilidad del OLEOZON® tópico. Métodos: Mediante el método dilución en agar fueron evaluadas cinco concentraciones del producto frente a los dermatofitos trichophyton rubrum, trichophyton mentagrophytes y epidermophyton floccosum. Resultados: Se obtuvo que el 8,9 mg/mL fue el valor de la CMI para las cepas evaluadas en el estudio vida de estante; se observó en el estudio acelerado el mismo valor frente a las cepas de trichophyton mientras que para epidermophyton floccosum fue de 17,8 mg/mL a excepción del envase frasco de vidrio del lote 803295 donde se obtuvo 8,9 mg/mL. El análisis estadístico, tanto del estudio acelerado como en vida de estante, mostró que existe diferencia estadísticamente significativa entre el primer y el último mes de ensayo, estas son las diferencias más apreciables en los lotes almacenados en frasco de vidrio. El OLEOZON® tópico almacenado en frasco de polietileno de alta densidad presentó mejores valores de actividad frente a los dermatofitos. Conclusiones: Todos los valores de la concentración mínima inhibitoria encontrados, independiente del tipo de envase, el tiempo o la temperatura de almacenamiento, muestran que el producto mantiene su actividad antifúngica. Se evidenció una similitud entre las cepas del género trichophyton en comparación con el género epidermophyton(AU)
Introduction: Currently fungal infections affect between 20 and 25percent of the population. Objective: To determine the minimum inhibitory concentration of two batches of OLEOZON® stored at temperatures of 5 and 30 0C in glass and high-density polyethylene containers, for 24 months as part of the stability study of topical OLEOZON®. Methods: Using the agar dilution method, five concentrations of the product were evaluated against the dermatophytes Trichophyton rubrum, Trichophyton mentagrophytes and Epidermophyton floccosum. Results: It was found that 8.9 mg/mL was the MIC value for the strains evaluated in this shelf life study; and the same value was observed in the accelerated study against the trichophyton strains, while for epidermophyton floccosum it was 17.8 mg/mL with the exception of the glass bottle container of batch 803295 where 8.9 mg/mL was obtained. The statistical analysis, both in the accelerated study and in shelf life, showed that there is a statistically significant difference between the first and the last month of the trial, these are the most appreciable differences in the batches stored in glass jars. Topical OLEOZON® stored in a high-density polyethylene bottle presented better activity values against dermatophytes. Conclusions: All the values of the minimum inhibitory concentration found, regardless of the type of container, the time or the storage temperature, show that the product maintains its antifungal activity during the months of study. A similarity was apparent between the strains of the genus trichophyton compared to the genus epidermophyton(AU)
Assuntos
Humanos , Masculino , Feminino , Testes de Sensibilidade Microbiana/métodos , Medicamentos de ReferênciaRESUMO
Abstract The present study was aimed at conducting phytochemical analysis and evaluating the in vitro antifungal and antioxidant activities of the essential oil obtained from the fruits of J. oxycedrus L. Hydro-distillation was used to extract the essential oil from the fruits of Juniper oxycedrus. The essential oil was analyzed using gas chromatography with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). The antioxidant activity of the essential oil against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals was determined in vitro using varying concentrations of the essential oil and vitamin C as a standard antioxidant compound. A disc diffusion test was employed to evaluate the antifungal activity of the essential oil against two test fungal strains, Penicillium citrinum, and Aspergillus niger. The results revealed that 49 constituents were identified in fruit oil, representing 91.56% of the total oil and the yield was 1.58%. Juniper fruit oil was characterized by having high contents of ß-pinene (42.04%), followed by limonene (15.45%), sabinene (9.52%), α-pinene (5.21%), (E)-caryophyllene (3.77%), ρ-cymene (1.56%), caryophyllene oxide (2.02%), and myrcene (1.02%). The radical scavenging activity (% inhibition) of the essential oil was highest (81.87± 2.83%) at a concentration of 200 µg/mL. The essential oil of J. oxycedrus exhibited antifungal activity against A. niger and P. citrinum with minimum inhibitory concentration values (MIC) ranging from 2.89 to 85.01 µl/mL. The findings of the study reveal that the antioxidant and antifungal properties of J. oxycedrus essential oil and their chemical composition are significantly correlated
Assuntos
Óleos Voláteis/análise , Juniperus/efeitos adversos , Compostos Fitoquímicos/análise , Frutas/classificação , Marrocos/etnologia , Antioxidantes/farmacologia , Espectrometria de Massas/métodos , Técnicas In Vitro/métodos , Testes de Sensibilidade Microbiana/métodos , Cromatografia Gasosa/métodos , Antifúngicos/farmacologiaRESUMO
Introduction: Staphylococcus aureus and Escherichia coli are pathogens that cause chronic infections due to antibiotic resistance mechanisms and their ability to adhere to surfaces and to form biofilms. The search for new agents from natural resources to counter microbial biofilms is an urgent priority in healthcare. Objetive: chemical composition, antibacterial and anti-biofilm activity of Plectranthus amboinicus essential oil (PAEO) and carvacrol were investigated against E. coli and S. aureus. Methodology: PAEO was chemically analyzed using gas chromatography coupled to a mass spectrometer. Antimicrobial activity was assessed by the disc diffusion method and broth microdilution method to determine minimum inhibitory concentrations (MICs). Antibiofilm activity was investigated using 96-well plates with a crystal violet assay. Results: carvacrol (85.25%) was the major component of PAEO. The disc diffusion test confirmed the ability of PAEO and carvacrol in inhibiting bacteria in their planktonic form. The MICs of PAEO against S. aureus and E. coli were 0.31 and 1.25%, respectively, with bactericidal effect. Carvacrol demonstrated a significant antibacterial property (MIC = 0.31%), exhibiting bacteriostatic effects against S. aureus and bactericidal effects against E. coli. Carvacrol considerably inhibited E. coli biofilm formations (58.9%). Moreover, carvacrol inactivated the mature biofilms. Conclusion: the data obtained are promising, and facilitates the development of new therapeutic alternatives. These results indicate the potential of carvacrol in treating diseases caused by E. coli and S. aureus
Introdução: Escherichia coli e Staphylococcus aureus são patógenos que podem causar infecções persistentes devido aos mecanismos de resistência e à sua capacidade de aderir e formar biofilme. A busca por novos agentes a partir de recursos naturais para combater o biofilme é uma prioridade na área da saúde. Objetivo: a composição química, a atividade antibacteriana e anti-biofilme do óleo essencial de Plectranthus amboinicus (PAEO) e do carvacrol foram investigadas frente a S. aureus e E. coli. Metodologia: a análise química do PAEO foi realizada por cromatografia gasosa acoplada a espectrômetro de massa. A atividade antimicrobiana foi avaliada por difusão em disco e microdiluição em caldo para determinar as concentrações inibitórias mínimas (CIMs). As atividades do anti-biofilme foram investigadas usando placas de 96 poços pelo ensaio de cristal violeta. Resultados: o carvacrol (85,25%) foi o principal componente do PAEO. A capacidade do PAEO e do carvacrol para inibir bactérias planctônica foi confirmada por difusão em disco. A CIM do PAEO para S. aureus e E. coli foi de 0,31 e 1,25%, respectivamente, com efeito bactericida. O carvacrol demonstrou uma propriedade antibacteriana significativa (CIM=0,31%), exibindo efeito bacteriostático frente a S. aureus e efeito bactericida para E. coli. O carvacrol inibiu significativamente a formação de biofilme de E. coli (58,9%) e promoveu a desestabilização do biofilme maduro. Conclusão: os dados obtidos são promissores, possibilitando o desenvolvimento de novas alternativas terapêuticas e revelam a potencialidade do carvacrol como fonte para o tratamento de doenças causadas por E. coli e S. aureus.
Assuntos
Staphylococcus aureus/efeitos dos fármacos , Óleos Voláteis/farmacologia , Biofilmes/efeitos dos fármacos , Plectranthus/química , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana/métodosRESUMO
Zinc oxide nanoparticles (ZnO NPs) are one of the most widely used nanoparticulate materials due to their antimicrobial properties, but their main mechanism of action (MOA) has not been fully elucidated. This study characterized ZnO NPs by using X-ray diffraction, FT-IR spectroscopy and scanning electron microscopy. Antimicrobial activity of ZnO NPs against the clinically relevant bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and the Gram-positive model Bacillus subtilis was evaluated by performing resazurin microtiter assay (REMA) after exposure to the ZnO NPs at concentrations ranging from 0.2 to 1.4 mM. Sensitivity was observed at 0.6 mM for the Gram-negative and 1.0 mM for the Gram-positive cells. Fluorescence microscopy was used to examine the interference of ZnO NPs on the membrane and the cell division apparatus of B. subtilis (amy::pspac-ftsZ-gfpmut1) expressing FtsZ-GFP. The results showed that ZnO NPs did not interfere with the assembly of the divisional Z-ring. However, 70% of the cells exhibited damage in the cytoplasmic membrane after 15 min of exposure to the ZnO NPs. Electrostatic forces, production of Zn2+ ions and the generation of reactive oxygen species were described as possible pathways of the bactericidal action of ZnO. Therefore, understanding the bactericidal MOA of ZnO NPs can potentially help in the construction of predictive models to fight bacterial resistance.
Assuntos
Bacillus subtilis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Óxido de Zinco/farmacologia , Bacillus subtilis/metabolismo , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana , Escherichia coli/metabolismo , Testes de Sensibilidade Microbiana/métodos , Pseudomonas aeruginosa/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/metabolismo , Eletricidade EstáticaRESUMO
BACKGROUND: Nocardia species are ubiquitous in natural environments and can cause nocardiosis. In the present study, the use of Resazurin salt and Spectrophotometry were proposed as alternative methods to reduce subjectivity in the interpretation of susceptibility results to antimicrobials by the broth microdilution method for Nocardia spp. RESULTS: The susceptibility of Nocardia spp. isolates to Amikacin, Ciprofloxacin, Minocycline and Trimethoprim-Sulfamethoxazole was evaluated by Minimum Inhibitory Concentration (MIC) determinations by the broth microdilution method. To verify cellular growth, the colour-changing dye Resazurin was applied, the Optical Densities were measured on a spectrophotometer, and both were compared to Clinical and Laboratory Standards Institute (CLSI) Gold Standard method (visual MIC determination). Percentages of essential and categorical agreements and interpretative categorical errors were calculated within each method (intra-reading) and between them (inter-reading). The Gold Standard visual reading demonstrated 100% of essential and categorical intra-reading agreements for Amikacin, and there was no error when compared with the alternative methods. For Ciprofloxacin, the comparison between the Gold Standard and the Spectrophotometric reading showed 91.5% of essential agreement. In the categorical intra-reading analysis for Minocycline, there were 88.1 and 91.7% in the Gold Standard and in the Spectrophotometric readings, respectively, and 86.4% of concordance between them. High rates of categorical agreement were also observed on the Trimethoprim-Sulfamethoxazole analyses, with 93.7% for the Gold Standard, 84.9% for the Resazurin readings, and 80.5% between them. CONCLUSIONS: The alternative methods with Resazurin and Spectrophotometric readings showed high agreement rates with the Gold Standard.
Assuntos
Testes de Sensibilidade Microbiana/métodos , Nocardia/isolamento & purificação , Antibacterianos/farmacologia , Humanos , Testes de Sensibilidade Microbiana/normas , Nocardia/efeitos dos fármacos , Nocardiose/microbiologia , Oxazinas , Espectrofotometria , XantenosRESUMO
With the spread of bacterial resistance against clinically used antibiotics, natural plant-derived products are being studied as new sources of antibacterial molecules. Manilkara zapota is a common plant species in the American continent that is used as a food source. Studies show the M. zapota extract is rich in phenolic substances that can serve as basic molecules for the pharmaceutical industry. An extract from fresh M. zapota leaves was produced and tested to identify the compounds present, as well as its direct antibacterial and clinical antibiotic modulatory activities. To analyze the results, a new statistical methodology based on the Shannon-Wiener index was tested, capable of correcting distortions in heterogeneous environments. The Hydroethanolic Extract of Manilkara zapota leaves (HEMzL) presented a wide variety of phenolic products, as well as tannins, in the UPLC analysis. The extract showed direct antibacterial activity against the standard Staphylococcus aureus strain, however, it either acted antagonistically when associated with the tested antibiotics, or it did not present statistical significance when compared to the control. This demonstrates a need to be cautious when associating natural products with antibiotics for clinical use, as a hindrance to infectious treatments may occur. As for the statistical analysis mechanism tested, this proved to be effective, reducing false negatives at low antibiotic concentrations and false positives at high concentrations in the microdilution plate.
Assuntos
Antibacterianos/farmacologia , Cromatografia Líquida/métodos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Manilkara/química , Espectrometria de Massas em Tandem/métodos , Animais , Antibacterianos/análise , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Humanos , Testes de Sensibilidade Microbiana/métodos , Fenóis/análise , Fenóis/farmacologia , Fitoterapia/métodos , Extratos Vegetais/análise , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/químicaRESUMO
Treatment of drug-resistant tuberculosis requires extended use of more toxic and less effective drugs and may result in retreatment cases due to failure, abandonment or disease recurrence. It is therefore important to understand the evolutionary process of drug resistance in Mycobacterium tuberculosis. We here in describe the microevolution of drug resistance in serial isolates from six previously treated patients. Drug resistance was initially investigated through phenotypic methods, followed by genotypic approaches. The use of whole-genome sequencing allowed the identification of mutations in the katG, rpsL and rpoB genes associated with drug resistance, including the detection of rare mutations in katG and mixed populations of strains. Molecular docking simulation studies of the impact of observed mutations on isoniazid binding were also performed. Whole-genome sequencing detected 266 single nucleotide polymorphisms between two isolates obtained from one patient, suggesting a case of exogenous reinfection. In conclusion, sequencing technologies can detect rare mutations related to drug resistance, identify subpopulations of resistant strains, and identify diverse populations of strains due to exogenous reinfection, thus improving tuberculosis control by guiding early implementation of appropriate clinical and therapeutic interventions.