RESUMO
ABSTRACT Infections of the oral cavity have a broad microbial etiological profile that varies according to each microenvironment in the mouth. Such infections often require antimicrobial treatment, which can lead to the development of resistance. There is thus a need to find new therapeutic strategies based on natural plant-derived compounds. The aim of this study was to determine the phytochemical nuclei and the antimicrobial effect of Anacardium excelsum leaf and stem extracts, and of fractions derived from the leaf extract, against Streptococcus mutans ATCC 25175, Staphylococcus aureus ATCC 35548, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 19433 and Candida albicans ATCC 10231. The plant material was collected from the Quindío Botanical Garden (Calarcá, Quindío-Colombia), located at an altitude of 1500 meters above sea level. Hydroalcoholic extracts of A. excelsum leaves and stems, and fractions of the hydroalcoholic leaf extract, were obtained by percolation extraction. Phytochemical nuclei were identified by thin layer chromatography. The antimicrobial activity of the extracts and fractions (at concentrations of 2, 5, 10, 20 and 40 mg / ml) against the five ATCC reference strains was evaluated using the well diffusion technique on Mueller-Hinton agar. The leaf extract showed no antimicrobial activity against E. coli, but it did show antimicrobial activity against S. mutans, S. aureus, E. faecalis and C. albicans, at a concentration of 10 mg/ml, with zones of inhibition of 9 to 11 mm. The ethyl acetate and acetone fractions obtained from A. excelsum leaf extract had greatest antimicrobial activity at 10 mg/ml. In conclusion, (1) the A. excelsum leaf extract, and the ethyl acetate and acetone fractions obtained from the leaf extract, had the greatest antimicrobial activity on all the study microorganisms, and (2) the phytochemical nuclei in the fractions (ethyl acetate and acetone) were found to contain phenolic-type compounds, tannins, triterpene-type terpenes and steroidal-type terpenes, which might explain the antimicrobial activity observed.
RESUMEN Las infecciones de la cavidad bucal se caracterizan por presentar un amplio perfil etiológico microbiano que varía de acuerdo a cada microambiente en boca. En muchos casos estas infecciones requieren tratamiento antimicrobiano que puede conducir al desarrollo de resistencia. Estos hechos en conjunto generan la necesidad de buscar nuevas estrategias terapéuticas, provenientes de compuestos naturales derivados de plantas. El objetivo de este estudio fue determinar los núcleos fitoquímicos y el efecto antimicrobiano de extractos de hojas y tallos, y de fracciones derivadas del extracto de hojas de Anacardium excelsum contra Streptococcus mutans ATCC 25175, Staphylococcus aureus ATCC 35548, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 19433 y Candida albicans ATCC 10231. El material vegetal se colectó del Jardín Botánico del Quindío (Calarcá, Quindío-Colombia), situado a una altura de 1500 msnm. Se obtuvieron extractos hidroalcohólicos de hojas y tallos, y fracciones a partir del extracto hidroalcohólico de hojas de A. excelsum mediante extracción por percolación. La identificación de los núcleos fitoquímicos fue realizado por cromatografía en capa delgada. La evaluación de la actividad antimicrobiana de extractos y fracciones, en concentraciones de 2, 5, 10, 20 y 40 mg/ml, frente a las 5 cepas de referencia ATCC, se realizó mediante la técnica de difusión con aplicación en pozo sobre agar Mueller-Hinton. El extracto de hojas no presentó actividad antimicrobiana sobre E. coli pero si sobre S. mutans, S. aureus, E. faecalis y C. albicans, en una concentración de 10 mg/ml, con halos de inhibición desde 9 a 11 mm, y las fracciones de acetato de etilo y acetona obtenidas del extracto de hojas de A. excelsum, presentaron mayor actividad antimicrobiana en una concentración de 10 mg/ml. En conclusión, 1. El extracto de hojas y las fracciones de acetato de etilo y acetona obtenidas del extracto de hojas de A. excelsum presentaron mayor actividad antimicrobiana sobre todos los microorganismos en estudio; 2. La evaluación de los núcleos fitoquímicos en las fracciones acetato de etilo y de acetona mostraron compuestos de tipo fenólico, taninos, terpenos del tipo triterpenos y terpenos del tipo esteroidal, que posiblemente expliquen la actividad antimicrobiana obtenida.
RESUMO
The purpose of the study was to analyze the effectiveness of adding nebulized antibiotics to systemic antimicrobials in critically ill patients with respiratory tract infections (pneumonia or tracheobronchitis) and the effect on renal function. A retrospective observational cohort study including critically ill patients with respiratory tract infections during a 2-year period was conducted. Intervention group included patients that received nebulized and systemic antimicrobials. Patients in the control group received only systemic antimicrobials. Clinical resolution was the primary endpoint. Secondary outcomes included change in fever, inflammatory parameters, and creatinine clearance; length of hospital stay, systemic therapy, and mechanical ventilation; hospital readmission; and mortality. Regression models were performed to estimate the effect of nebulized antibiotics on outcome variables adjusted by potential confounders. A total of 136 patients were included (93 in control group and 43 in intervention group). The intervention group had higher odds of clinical resolution (adjusted odds ratio (OR): 7.1; 95% confidence interval (95% CI): 1.2, 43.3). Nebulized antibiotic therapy was independently associated with reduction in procalcitonin (adjusted OR: 12.4; 95% CI: 1.4, 109.7). There were no significant differences in the rest of the secondary outcomes or in creatinine clearance reduction. Adding nebulized antibiotics for the management of respiratory tract infections has a positive impact on clinical resolution without increasing the risk of renal toxicity.
