Meningitis posquirúrgica por Acinetobacter baumannii multirresistente. Actividad sinérgica in vivo de la asociación sulbactam/avibactam / Post-surgical meningitis due to multiresistant Acinetobacter baumannii. In vivo synergistic activity of the sulbactam/avibactam association

Acinetobacter baumannii (AB) es un bacilo gram negativo, no fermentador,con frecuencia oportunista, ubicuo en el medio ambiente, con capacidad para sobrevivir en condiciones medioambientales adversas promoviendo su persistencia y diseminación en diferentes áreas de un hospital. Ha sido relacionado con múltiples brotes de infecciones asociadas al cuidado de la salud como neumonía, bacteriemias, contaminación de heridas quirúrgicas o infecciones del tracto urinario, especialmente entre pacientes con comorbilidades graves, como aquellos que motivan el ingreso a unidades de cuidados intensivos (UCI). Las cepas más problemáticas son aquellas resistentes a los carbapenémicos, resistencia causada por enzimas de la clase de las oxacilinasas (bla OXA) cromosómicas o plasmídicas y más recientemente bla NDM-1. La aparición de estas cepas deja escasos antimicrobianos activos (colistin, minociclina, tigeciclina; amikacina) que son limitados en su eficacia y su uso se asocia con toxicidad. A esto se agrega, como en la paciente que se describe, que desarrolló una meningitis posquirúrgica, la limitada capacidad de difusión en el sistema nervioso central (SNC) de estas últimas opciones. Una de las alternativas terapéuticas, es buscar asociaciones como sulbactam/avibactam que mostraron una adecuada actividad sinérgica y bactericida en asilamientos resistentes a ampicilina/sulbactam en base a una significativa reducción de la CIM que permite administrar dosis habituales, con mejor tolerancia y lograr concentraciones terapéuticas en SNC. Se presenta una paciente que desarrolló una meningitis posquirúrgica debida a una cepa de AB multirresistente.

Acinetobacter baumannii (AB) is a non-fermenting gram-negative bacillus, largely opportunistic, ubiquitous in the environment, with the ability to survive in adverse environmental conditions, promoting its persistence and dissemination in different areas of the hospital. It has been implicated in many outbreaks of healthcare-associated infections such as pneumonia, bacteremia, surgical wounds contamination, or urinary tract infections, especially among patients with previous severe illnesses such as those requiring admission to intensive care units (ICU). The most problematic strains are those resistant to carbapenems, resistance caused by chromosomal or plasmid oxacillinase class (bla OXA), and more recently bla NDM-1. The appearance of these strains leaves few active antimicrobials (Colistin, Minocycline, Tigecycline; Amikacin) that are limited in their efficacy and toxic. To this we must add, as is the case of our patient who presented post-surgical meningitis, the limited diffusion capacity in the central nervous system (CNS) of these last options. One of the therapeutic alternatives is to search for synergistic associations such as sulbactam/avibactam that showed rapid synergistic and bactericidal activity in isolates resistant to ampicillin/sulbactam due to a significant reduction in its MIC, which allows us to administer usual, better tolerated doses that reach therapeutic concentrations in CNS. Here, we present a patient who developed a post-surgical meningitis due to multiresistant AB

Combinación de antidepresivos vs. aumentación con antipsicóticos atípicos tras no lograr la remisión en la depresión unipolar / Combination of antidepressants vs. augmentation with atypical antipsychotics upon failure to achieve remission in unipolar depression

RESUMEN: Introducción: Lograr la recuperación funcional lo más rápido posible en el tratamiento de la depresión unipolar es un reto que la práctica clínica debe tratar de afrontar en la actualidad, ya que cualquier retraso en lograr la remisión de los síntomas es predictivo de un mayor número de recurrencias y mayores tasas de morbimortalidad. En esta revisión comprensiva, nuestro objetivo es guiar a los clínicos en su elección de aumentar con antipsicóticos atípicos o combinar el fármaco de referencia con un segundo antidepresivo, después de que se haya optimizado la dosis del antidepresivo seleccionado inicialmente y/o se haya cambiado el antidepresivo, sin lograr remisión, o bien cuando solo han obtenido una respuesta parcial después de un tiempo suficiente a una dosis apropiada. Estas decisiones surgen con frecuencia en la práctica clínica diaria. Metodología: Se realizó una búsqueda sistemática en PubMed bajo varias combinaciones clave de palabras, resultando en 230 informes. Después de aplicar los criterios de inclusión y según el título y el resumen, el número final de informes seleccionados para la revisión completa fue de 113. Se respondieron dos preguntas principales con base en estos estudios: 1) ¿Existe evidencia para recomendar claramente la combinación de antidepresivos versus potenciación con antipsicóticos (y el momento correcto para hacerlo) en la depresión unipolar no respondedora, una vez que las estrategias de optimización o de cambio han fallado en obtener la remisión? y 2) ¿Es posible identificar algunas características clínicas para guiar la decisión de combinación de antidepresivos versus potenciación con agentes antipsicóticos? Resultados: Según nuestro análisis, no hay datos disponibles para seleccionar una estrategia de otra de manera clara. Sin embargo, sugerimos favorecer una combinación o estrategia de aumento, basada en un enfoque de "tratamiento contra objetivos dianas" para perfilar al paciente, considerando una o dos características clínicas predominantes que permanecen activas como parte de una depresión mayor con respuesta parcial. Un adecuado análisis de los dominios sintomáticos presentes, una visión crítica de las guías clínicas actuales y de las opciones preferidas, considerar la bipolaridad oculta como uno de los principales diagnósticos diferenciales y adoptar una actitud enérgica pero lúcida en esta etapa del tratamiento son, a nuestro juicio, fundamentales para lograr recuperación ad integrum del paciente.

ABSTRACT Introduction: achieving functional recovery as quickly as possible in the treatment of unipolar depression is a challenge that clinical practice must try to meet nowadays, since any delay in accomplishing remission of the symptoms is predictive of a larger number of recurrences and higher morbidity and mortality rates. In this topical review we aim to guide clinicians in their choice to augment with atypical antipsychotics or to combine the baseline drug with a second antidepressant, after the dose of the antidepressant initially selected has been optimized and/or the antidepressant has been changed, not achieving remission, or resulting only in a partial response after sufficient time at an appropriate dose. These decisions arise frequently in everyday clinical practice. Methodology: a systematic search in PubMed was performed under several key combinations of words, resulting in 230 reports. After applying inclusion criteria and based in title and abstract, the final number of reports selected for full revision were 113. Two main questions were answered based on these studies: 1) Is there evidence to clearly recommend combination of antidepressants vs. augmentation with antipsychotics (and the correct moment to do it) in non-responsive unipolar depression, once optimization or switching strategies have failed to obtain remission? and 2) Is it possible to identify some clinical features to guide the decision of combination of antidepressants vs. augmentation with antipsychotic agents? Results: According to our analysis, there is no data available to select one strategy from another in a clear-cut manner. Nevertheless, we suggest favoring a combination or augmentation strategy, based in a "treating to target" approach to profile the patient, considering one or two predominant clinical features that remain active as part of a major depression with partial response. Proper analysis of the symptomatic domains present, a critical view of current clinical guidelines and preferred options, considering hidden bipolarity as one of the main differential diagnoses and adopting an energetic but lucid attitude at this stage of treatment are, in our view, fundamental for achieving ad integrum patient recovery.

Synergy in penicillin, cephalosporin, amphenicols, and aminoglycoside against MDR S. aureus isolated from Camel milk

Abstract This study investigated the synergy testing of penicillin, cephalosporin, amphenicols, and aminoglycoside in the camel milk (n=768 samples), subsequently used for isolation of MDR S. aureus targeting mecA gene. Antibiotic susceptibility of S. aureus showed >90% isolates were sensitive to ciprofloxacin and trimethoprim and resistant against oxacillin, ampicillin, and cefoxitin. Further, 50-85% of the S. aureus were sensitive to gentamicin, oxytetracycline, and chloramphenicol and resistant against cefotaxime, vancomycin, and cefixime. Minimum inhibitory concentration (MIC) of cefotaxime, (C) and ampicillin (A) in combination with gentamicin (G) was reduced by 99.34% and 70.46%, respectively, while with chloramphenicol (Ch), reduction was 57.49% and 60%, respectively. In addition, the Fractional Inhibitory Concentration Index (FICI) of G+A, Ch+C and Ch+G combinations showed synergy against 80%, 60%, and 30% of MDR S. aureus, respectively. Similarly, C+A and Ch+G displayed indifferent interaction against 70 % and 30% of isolates, respectively, while the later showed additive interaction against 10% of MDR S. aureus. Altogether, our results described effective combination of gentamicin and chloramphenicol with ampicillin and cefotaxime to combat MDR S. aureus

Efeitos sinérgicos antimicrobianos da combinação dos extratos de sálvia e alcaçuz sobre cepas clínicas de Enterococcus faecalis e Enterococcus faecium / Synergistic antimicrobial effects of the combination of sage and licorice extracts on clinical strains of Enterococcus faecalis and Enterococcus faecium

A crescente busca pelo conhecimento do potencial biológico presente nas plantas medicinais tem estimulado pesquisas, principalmente no que diz respeito ao potencial antimicrobiano dos extratos de plantas. Entretanto, mais estudos sobre os efeitos sinérgicos da combinação desses extratos são fundamentais para sua maior aplicação clínica. O objetivo desse estudo foi avaliar in vitro os efeitos sinérgicos antimicrobianos das associações dos extratos naturais de Salvia officinalis (S. officinalis) e Glycyrrhiza glabra (G. glabra). Foi realizada a análise antimicrobiana sobre três cepas clínicas de Enterococcus faecalis (E. faecalis), duas cepas clínicas de Enterococcus faecium (E. faecium) e uma cepa padrão de cada espécie. Foram determinadas as Concentração Inibitória Mínima (CIM) e Concentração Microbicida Mínima (CMM) por microdiluição em caldo com semeadura, e Índice de Concentração Inibitória Fracionada (ICIF) pela técnica checkerboard. Para avaliar o efeito combinado dos extratos sobre biofilme foram utilizadas duas combinações dos extratos sobre biofilme formado de E. faecalis e sobre biofilme formado de E. faecium, por dois períodos diferentes: 5 minutos e 24 h, e foram avaliados os valores médios de unidades formadoras de colônias por mililitro (UFC/mL). A análise estatística foi feita aplicando método ANOVA e teste de Tukey ou Kruskall-Wallis e Dunn (significância de 5%). Os extratos de S. officinalis e G. glabra apresentaram concentração microbicida para as cepas avaliadas. A combinação dos extratos apresentou valores indiferentes (ICIF ˃ 0,5 e ≤ 4) para as cepas de E. faecium, e valores indiferentes e sinérgicos (ICIF ≤0,5) para cepas de E. faecalis. Sobre biofilme as duas combinações apresentaram reduções estatisticamente significantes do grupo controle negativo (p < 0,05). Dessa forma concluiu-se que a combinação dos extratos de S. officinalis e G. glabra possui feito sinérgico antimicrobiano contra E. faecalis e atividade antibiofilme contra E. faecalis e E. faecium (AU)

The growing search for knowledge of the biological potential present in medicinal plants has stimulated research, especially with regard to the effective antimicrobial potential of plant extracts, however, further studies on the synergistic effects of the combination of these extracts is essential for their greater clinical application. The aim of this study was to evaluate in vitro the synergistic antimicrobial effects of the association of natural extracts of Salvia officinalis (S. officinalis) and Glycyrrhiza glabra (G. glabra). Antimicrobial analysis was performed on three clinical strains of Enterococcus faecalis (E. faecalis), two clinical strains of Enterococcus faecium (E. faecium) and one standard strain of each species. The Minimum Inhibitory Concentration (MIC) and Minimum Microbicidal Concentration (MMC) were determined by microdilution in broth with seeding, and Fractional Inhibitory Concentration Index by the checkerboard technique. To evaluate the combined effect of extracts on biofilm, two combinations of extracts on biofilm formed by E. faecalis and on biofilm formed by E. faecium were used, for two different periods: 5 min and 24 h, and the mean values of units were evaluated. colony forming agents per milliliter (CFU/mL). Statistical analysis was performed using the ANOVA method and Tukey's or Kruskall-Wallis and Dunn's test (5% significance). The extracts of S. officinalis and G. glabra showed microbicidal concentration for the strains evaluated. The combination of extracts showed indifferent values (FICI ˃ 0.5 and ≤ 4) for E. faecium strains, and indifferent and synergistic values FICI ≤0.5) for E. faecalis strains. On biofilm, the two combinations showed statistically significant reductions compared to the negative control group (p < 0.05). Thus, it is concluded that the combination of extracts of S. officinalis and G. glabra has synergistic antimicrobial effect against E. faecalis and antibiofilm activity against E. faecalis and E. faecium (AU)

Structural elucidation, mechanism of action, antibacterial proficiency and synergistic forte of purified Euphorbia hirta whole plant extract against multi-drug resistant otitis media infection / Elucidación estructural, mecanismo de acción, competencia antibacteriana y fuerza sinérgica del extracto de planta entera de Euphorbia hirta purificado contra la infección por otitis media resistente a múltiples fármacos

This study investigated the antibacterial potential of Euphorbia hirtawhole plant extracts, honey and conventional antibiotics and their synergistic effects against selected multidrug resistant and typed bacterial strains associated with otitis media. E. hirtawhole plant extract was purified using column chromatography technique. The antibacterial assays of extracts were done using standard microbiological procedures. Protein, sodium and potassium ion leakage of the synergistic mixtures was determined using flame-photometry. At 100 mg/ml, acetone extracts presented highest inhibition against S. aureus (NCTC 6571) with 32 ± 0.83 mm zone of inhibition. The fractional inhibitory concentration indices displayed higher synergism in combination of plant extract, honey and ciprofloxacin against P. mirabilisat 0.02 compared to drug combination synergy standard (≤ 0.5). This work revealed augmentation of ciprofloxacin potency when combined with purified E. hirta acetone extract and honey and implies their high potential in the treatment of multidrug resistant infectionof otitis media.

Este estudio investigó el potencial antibacteriano de extractos de plantas enteras de Euphorbia hirta, miel y antibióticos convencionales y sus efectos sinérgicos contra cepas bacterianas seleccionadas multirresistentes y tipificadas asociadas con la otitis media. El extracto de la planta entera de E. hirtase purificó usando la técnica de cromatografía en columna. Los ensayos antibacterianos de extractos se realizaron utilizando procedimientos microbiológicos estándar. La fuga de iones de proteínas, sodio y potasio de las mezclas sinérgicas se determinó mediante fotometría de llama. A 100 mg/ml, los extractos de acetona presentaron la mayor inhibición contra S. aureus (NCTC 6571) con una zona de inhibición de 32 ± 0,83 mm. Los índices de concentración inhibitoria fraccional mostraron un mayor sinergismo en combinación de extracto de planta, miel y ciprofloxacina contra P. mirabilisa 0,02 en comparación con el estándar de sinergia de combinación de fármacos (≤ 0,5). Este trabajo reveló un aumento de la potencia de la ciprofloxacina cuando se combina con extracto de acetona purificado de E. hirtay miel e implica sualto potencial en el tratamiento de infecciones de otitis media resistentes a múltiples fármacos.

Vascular interactions of Croton schiedeanus major flavonoids in isolated aortic rings from Wistar rats / Interacciones vasculares de los principales flavonoides de Croton schiedeanus en anillos aislados de aorta de ratas Wistar

Background: Ayanin (3,7,4'-Tri-O-methylquercetin) and 3,7-Di-O-methylquercetin (DMQ) are the main active metabolites isolated by bioguided fractionation from Croton schiedeanus, species known popularly in Colombia as "almizclillo", which has been studied in experimental models in rats, exerting vasodilator and antihypertensive effects. Also, when the effect of these flavonoids was studied separately, important vasodilation was observed. Objective:To evaluate whether flavonoids from Croton schiedeanus have synergistic vasodilator properties when different combinations are used in isolated aorta rings. Methods: Cumulative concentrations of ayanin (10-8 M - 6x10-5 M or 0.01 µM - 60 µM) were assayed in the absence and presence of an increasing concentration of 3,7-Di-O-methylquercetin (DMQ) (10-8 ­ 3x10-5M or 0.01­30 µM) in isolated rings from Wistar rats, pre-contracted with phenylephrine. The concentration-response curve with the maximal effect was compared with that obtained by Croton schiedeanus whole ethanolic extract (10-6 ­ 3x10-4 g/mL). Also, this combination was assayed in the presence of the nitric oxide synthetase inhibitor L-NAME (10-4 M) and the guanylate cyclase inhibitor methylene blue (10-4 M) to assess the role of the NO/cGMP pathway in this interaction. Results: Ayanin and DMQ display a dual interaction in vascular relaxant response: agonism at higher concentration ranges (10-6 ­ 3x10-5 M or 1­30 µM) and antagonism at lower concentration ranges (10-8 ­ 3x10-7 M or 0.01­0.3 µM). The efficacy at the highest concentration was greater than that obtained by the whole extract (Emax: 98.4% vs. 33.9%). This response was decreased but not reverted in the presence of L-NAME and methylene blue. Thus, the vasodilator effect of this combination does not depend entirely on the NO/cGMP cyclic pathway. Conclusion: The combined use of appropriate concentrations of these flavonoids could represent an advantage over Croton schiedeanus whole extract for vasodilator purposes

Antecedentes: Ayanina (3,7,4'-Tri-O-metilquercetina) y 3,7-Di-O-metilquercetina (DMQ) son los principales metabolitos activos aislados mediante fraccionamiento bioguiado, a partir de Croton schiedeanus, especie conocida popularmente en Colombia como "almizclillo", la cual ha sido estudiada en modelos experimentales en ratas, ejerciendo efectos antihipertensivos y vasodilatadores. Además, al estudiar por separado el efecto de los flavonoides, se observó importante vasodilatación. Objetivo:Evaluar si los principales flavonoides de Croton schiedeanus tienen propiedades vasodilatadoras sinérgicas al utilizar diferentes combinaciones de ellos en anillos de aorta aislados. Metodología: Se analizaron concentraciones acumulativas de ayanina (10-8 M - 6x10-5 M o 0,01 µM - 60 µM) en ausencia y en presencia de concentraciones crecientes de DMQ (10-8 M - 3x10-5 M o 0,01 µM ­ 30 µM) en anillos aislados de ratas Wistar, pre-contraídos con fenilefrina. La curva concentración respuesta obtenida con el efecto máximo, fue comparada con la obtenida con el extracto etanólico de Croton schiedeanus (10-6 - 3x10-4 g/mL). Adicionalmente, esta combinación fue ensayada en presencia del inhibidor de óxido nítrico sintetasa L-NAME (10-4 M) y el inhibidor de guanilato ciclasa, azul de metileno (10-4 M) para evaluar el papel de la vía NO/GMPc en esta interacción. Resultados: Ayanina y DMQ muestran una interacción dual en la respuesta vascular relajante: agonismo en el rango más alto (10-6 M ­ 3x10-5 M o 1 µM ­ 30 µM), y antagonismo en el rango más bajo (10-8 M ­ 3x10-7 M o 0.01 µM ­ 0,3 µM). A altas concentraciones, la eficacia de los flavonoides fue mayor que las obtenidas por el extracto completo (Emáx: 98,4% vs 33,9%). Esta respuesta disminuyó, pero no se revirtió en presencia de L-NAME y azul de metileno. Por lo tanto, el efecto vasodilatador de esta combinación no depende enteramente de la vía NO/GMPc. Conclusión: El uso combinado de las concentraciones apropiadas de estos flavonoides podría representar una ventaja sobre el extracto de Croton schiedeanus, con propósitos vasodilatadores

Atividades farmacológicas da manteiga de bacuri (Platonia insignis Mart): revisão integrativa / Pharmacological actions of bacuri butter (Platonia insignis Mart): an integrative review

RESUMO Objetivo identificar as atividades farmacológicas da manteiga de bacuri (Platonia insignis Mart.). Métodos revisão integrativa, realizada nas bases de dados Literatura Latino-americana e do Caribe em Ciências da Saúde, Cumulative Index to Nursing and Allied Health Literature, EMBASE, MEDLINE/PubMed, Web of Science, Cochrane Library e SCOPUS, sem delimitação temporal e de idioma. A seleção se constituiu de 13 ensaios pré-clínicos. A avaliação das informações ocorreu de forma descritiva, confrontando com os achados pertinentes. Resultados observou-se que 50,0% das publicações foram indexadas na MEDLINE/PubMed, maioria das publicações ocorreram na Inglaterra (61,5%), seguidas do Brasil e dos Estados Unidos, ambos com 13,3%. Destaca-se que 100,0% dos artigos foram ensaios pré-clínicos; atividades farmacológicas para antioxidante (38,4%) e antileishmanicidas (30,7%). Registrou-se que 38,4% dos ensaios apresentaram testes de toxicidade. Conclusão a manteiga de bacuri (Platonia insignis Mart.) apresentou atividades farmacológicas em ensaios pré-clínicos, como antioxidantes, antileshimaniose, anticonvulsivante e cicatrização de feridas.

ABSTRACT Objective to identify the pharmacological activities of bacuri butter (Platonia insignis Mart.). Methods an integrative review, carried out in the databases of Latin American and Caribbean Literature in Health Sciences, Cumulative Index to Nursing and Allied Health Literature, EMBASE, MEDLINE/PubMed, Web of Science, Cochrane Library and SCOPUS, without the time and language restriction. The selection consisted of 13 pre-clinical trials. The information assessment descriptively took place, comparing with the pertinent findings. Results it was observed that 50.0% of the publications were indexed in MEDLINE/PubMed, most publications were from England (61.5%), followed by Brazil and the United States, both with 13.3%. It is noteworthy that 100.0% of the articles were pre-clinical trials; pharmacological activities for antioxidants (38.4%) and antileishmanicides (30.7%). It was found that 38.4% of the trials presented toxicity tests. Conclusion bacuri butter (Platonia insignis Mart.) Showed pharmacological activities in pre-clinical trials, such as antioxidants, antileshimaniasis, anticonvulsant and wound healing.

Synergistic effects of binary mixtures of linalool with pyrethroids against fall armyworm / Efeitos sinérgicos de misturas binárias de linalol com piretroides contra lagarta-do-cartucho

The present work aimed to determine the toxicity of linalool and evaluate the lethal and toxic effects of linalool associated with pyrethroids in binary mixtures to fall armyworm (Spodoptera frugiperda). The insects used in the experiment were obtained from stock breeding initiated from larvae collected from conventional corn plants, grown in an experimental area, in the city of Uberlândia, Minas Gerais. Also, it was obtained essential oil from a variety of Ocimum basilicum, with a high content of linalool (80%), found naturally, as a measure of comparison of different linalool (97.5%) assays. Dose-response bioassays with 3rd instar larvae were performed to determine lethal dose for 50% mortality (LD50) of linalool. Toxicity tests were also performed with O. basilicum essential oil and with pyrethroid insecticides: deltamethrin and its commercial product (Decis 25 EC, Bayer®). After this, combinations between different doses of these products were made and applied on 3rd instar larvae of Spodoptera frugiperda (Smith). Linalool presented high toxicity to S. frugiperda (LD50 = 0.177 µL a.i. µL-1). It was observed neurotoxic effects after the linalool application since the insects presented an aspect of confusion, followed by extreme agitation and finally death. All binary mixtures caused mortality higher than the products applied alone (deltamethrin and linalool) used at 100% LD50, except to 75% LD50 deltamethrin added to 25% LD50 linalool, whose mortality did not differ the products alone, in 24 hours. It was obtained over 90% larval mortality when linalool was combined with 25% LD50 of deltamethrin, in 24 and 48 hours after application, and over 80% of mortality when linalool was combined with 25% LD50 of Decis, only in 48 hours after application. We conclude that linalool is a potential insecticidal and can be associated with pyrethroids to control of S. frugiperda. Further studies are required in order to evaluate the synergistic combinations against field populations of S. frugiperda.

O objetivo deste trabalho foi determinar a toxicidade do linalol e avaliar os efeitos tóxicos e letais do linalol associado a piretroides em misturas binárias para lagarta do cartucho do milho (Spodoptera frugiperda). Os insetos utilizados no experimento foram obtidos de criação estoque iniciada a partir de larvas coletadas em plantas de milho convencional, cultivado em área experimental, no município de Uberlândia, Minas Gerais. Também foi obtido óleo essencial de uma variedade de Ocimum basilicum, com alto teor de linalol (80%), encontrado naturalmente, como medida de comparação para ensaios com linalol (97.5%). Os bioensaios do tipo dose-resposta com larvas de 3º instar foram realizados para determinar a dose letal do linalol para 50% de mortalidade da população (DL50). Também foram realizados testes de toxicidade com óleo essencial de Ocimum basilicum e com inseticidas piretroides: deltametrina e seu produto comercial (Decis 25 EC, Bayer®). Em seguida, foram realizadas combinações entre diferentes doses desses produtos e aplicadas em larvas de 3º instar de Spodoptera frugiperda (Smith). De acordo com os resultados, observou-se que o linalol apresentou alta toxicidade para S. frugiperda (DL50 = 0,177 µL a. i. µL-1). Foram observados efeitos neurotóxicos após a aplicação do linalol, uma vez que os insetos apresentaram um aspecto de confusão, seguido de extrema agitação e, por fim, morte. Todas as combinações binárias causaram mortalidade maior que os produtos aplicados isoladamente (deltametrina e linalol) utilizando-se 100% da DL50, exceto para 75% DL50 de deltametrina somada a 25% DL50 de linalol, cuja mortalidade não diferiu dos produtos isolados, em 24 horas após a aplicação. Foi obtida mais de 90% de mortalidade de larvas quando se combinou linalol com 25% da DL50 de deltametrina, em 24 e 48 horas após a aplicação, e mais de 80% de mortalidade quando se combinou linalol com 25% da DL50 do produto comercial, somente 48 horas após a aplicação. Concluímos que o linalol é um potencial inseticida e pode ser associado a piretroides no controle de S. frugiperda. Mais estudos são necessários em vista de avaliar as combinações sinérgicas contra populações de campo de S. frugiperda.

Antimicrobial effects of fentanyl and bupivacaine: an in vitro study / Efeitos antimicrobianos do fentanil e da bupivacaína: estudo in vitro

Abstract Study objective: In this study, we aimed to compare the antimicrobial effects of bupivacaine and fentanyl citrate and to reveal the impact on antimicrobial effect potential in the case of combined use. Design: In vitro prospective study. Setting: University Clinical Microbiology Laboratory. Measurements: In our study, in vitro antimicrobial effect of 0.05 mg.mL-1 fentanyl citrate, 5 mg.mL-1 bupivacaine were tested against Staphylococcus aureus American Type Culture Collection (ATCC) 29213, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231 as Group F (Fentanyl Citrate) and Group B (Bupivacaine), respectively. S. aureus ATCC 29213, P. aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883 and Escherichia coli ATCC 25922 were cultured onto Mueller Hinton agar (Oxoid, UK) plates and Candida albicans ATCC 10231 were cultured onto Sabouraud dextrose agar (Oxoid, UK) plates for 18-24 hours at 37 °C. Main results: In terms of inhibition zone diameters, S. Aureus ATCC 29213, P. aeruginosa ATCC 27853, and C. albicans ATCC10231 values obtained after 12 and 24 hours of incubation ​​were significantly higher in Group F than Group B (p < 0.001). In terms of inhibition zone diameters, E. coli ATCC 25922, and K. pneumomiae ATCC 13883 values obtained after 12 and 24 hours of incubation ​​were significantly higher in Group B than Group F (p < 0.001, E. coli 12ª hour p = 0.005). Conclusions: Addition of fentanyl to Local Anesthetics (LAs) is often preferred in regional anesthesia applications in today's practice owing especially to its effect on decreasing the local anesthetic dose and increasing analgesia quality and patient satisfaction. However, when the fact that fentanyl antagonized the antimicrobial effects of LAs in the studies is taken into account, it might be though that it contributes to an increase in infection complications. When the fact that fentanyl citrate which was used in our study and included hydrochloric acid and sodium hydroxide as protective agents, broadened the antimicrobial effect spectrum of LAs, had no antagonistic effect and showed a synergistic antimicrobial effect against E. Coli is considered, we are of the opinion that the addition of fentanyl to LAs would contribute significantly in preventing the increasing regional anesthesia infection complications.

Resumo Objetivo: O objetivo do presente estudo foi comparar os efeitos antimicrobianos da bupivacaína e citrato de fentanil e revelar o impacto no potencial do efeito antimicrobiano no caso de uso combinado. Desenho: Estudo prospectivo in vitro. Local: Laboratório de Microbiologia Clínica da Universidade. Medidas: Em nosso estudo, os efeitos antimicrobianos in vitro do citrato de fentanil na concentração de 0,05 mg.mL-1 - Grupo F e da bupivacaína na concentração de 5 mg.mL-1 - Grupo B foram testados em culturas de Staphylococcus aureus ATCC 29213 (do inglês American Type Culture Collection 29213), Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883, Escherichia coli ATCC 25922 e Candida albicans ATCC 10231. As culturas de S. aureus ATCC 29213, P. aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883 e Escherichia coli ATCC 25922 foram semeadas em placas de ágar Mueller Hinton (Oxoid, Reino Unido), e a cultura de Candida albicans ATCC 10231 foi realizada em placa de ágar Sabouraud dextrose (Oxoid, Reino Unido) durante 18-24 horas a 37 °C. Principais resultados: Com relação ao diâmetro da zona de inibição, os valores de S. aureus ATCC 29213, P. aeruginosa ATCC 27853 e C. albicans ATCC10231 obtidos após 12 e 24 horas de incubação foram significantemente maiores no Grupo F do que no Grupo B (p < 0,001). Os valores do diâmetro da zona de inibição das culturas de E. coli ATCC 25922 e K. pneumomiae ATCC 13883 obtidos após 12 e 24 horas de incubação foram significantemente maiores no Grupo B do que no Grupo F (p < 0,001, E. coli na 12ª hora p = 0,005) Conclusões: A preferência atual e frequente pela adição de fentanil aos Anestésicos Locais (AL) para a realização de anestesia regional se deve sobretudo à possibilidade de redução da dose do anestésico local, a melhora na qualidade da analgesia e a satisfação do paciente. No entanto, ao considerar estudos em que o fentanil antagonizou o efeito antimicrobiano dos AL, pode-se pensar que esse fato contribua para aumento de complicação infecciosa. O citrato de fentanil usado em nosso estudo, contendo ácido clorídrico e hidróxido de sódio como agentes conservantes, ampliou o espectro de efeitos antimicrobianos dos AL, não teve efeito antagônico e demonstrou efeito antimicrobiano sinérgico contra a E. coli. Acreditamos que a adição de fentanil aos anestésicos locais traria importante contribuição na prevenção das crescentes complicações por infecção da anestesia regional.

In vitro effectivity of three approved drugs and their synergistic interaction against Leishmania infantum / Efectividad in vitro de tres fármacos aprobados y su interacción sinérgica contra Leishmania infantum

Introduction: Leishmaniasis remains one of the neglected tropical diseases. Repurposing existing drugs has proven to be successful for treating neglected tropical diseases while combination therapy is a strategic alternative for the treatment of infectious diseases. Auranofin, lopinavir/ritonavir, and sorafenib are FDA approved drugs used in the treatment of diverse diseases by acting on different essential biological enzymes. Objective: To evaluate the effects of monotherapy and combined therapies with the three drugs against Leishmania infantum. Materials and methods: We compared the leishmanicidal effects of the three drugs on promastigotes in vitro as regards the parasite count, the drug concentration providing a half-maximal response, and the ultrastructural changes of the parasite. We determined the fractional inhibitory concentration index of combined drugs in two ways, as well as the activity of the three drugs together to establish their synergetic effect. Results: The monotherapy with the three drugs was effective with auranofin showing the best leishmanicidal effect (EC50=1.5 µM), whereas sorafinib reduced parasite growth at EC50=2.5 µM. The scanning electron microscopy of promastigotes from all treated media showed distortion in the shape with loss of flagella and bleb formation. Acidocalcinosis was evident by transmission electron microscopy with all treatments suggesting apoptosis. Treatment with lopinavir/ritonavir showed signs of autophagy. The two-way combination of the drugs led to additive interactions while the combination of the three drugs showed synergistic action. Conclusion: Each drug when used as monotherapy against Leishmania spp. was effective, but the combination therapy was more effective than the individual drugs due to the additive or synergistic effects.

Introducción. La leishmaniasis sigue siendo una de las enfermedades tropicales desatendidas. La reutilización de medicamentos existentes ha demostrado ser exitosa para tratar enfermedades tropicales desatendidas y la terapia combinada es una alternativa estratégica para el tratamiento de enfermedades infecciosas. Auranofin, lopinavir/ritonavir y sorafenib son medicamentos aprobados por la Food and Drug Administration (FDA) de Estados Unidos utilizados en el tratamiento de diversas enfermedades, pues actúan sobre diferentes enzimas biológicas esenciales. Objetivo. Evaluar los efectos terapéuticos de la monoterapia y de los tres fármacos combinados contra Leishmania infantum. Materiales y métodos. Los efectos leishmanicidas de los tres fármacos sobre los promastigotes se compararon in vitro en cuanto al recuento de parásitos, la concentración del fármaco que proporcionara una respuesta semimáxima y los cambios ultraestructurales del parásito. Se calculó el índice de concentración inhibitoria de fracciones de fármacos combinados de dos maneras y la actividad de los tres fármacos juntos para determinar el efecto sinérgico. Resultados. La monoterapia con los tres medicamentos fue efectiva, pero la auranofina tuvo el mejor efecto antileishmanicida con un CE50 de 1,5 µM, en tanto que el sorafinib redujo el crecimiento del parásito con un CE50 de 2,5 µM. La microscopía electronica de barrido de promastigotes de todos los medios tratados mostró una distorsión en la forma, con pérdida de flagelos y formación de ampollas. La acidocalcinosis fue evidente por microscopía electrónica de transmisión con todos los tratamientos, lo que sugiere apoptosis. El tratamiento con lopinavir/ritonavir mostró signos de autofagia. La combinación de dos medicamentos condujo a interacciones aditivas, mientras que la combinación de las tres drogas produjo una acción sinérgica. Conclusión. Los tres medicamentos usados como monoterapia contra Leishmania spp. fueron efectivos, pero el tratamiento combinado lo fue en mayor medida debido a los efectos aditivos o sinérgicos.

Synergic effect of simvastatin in combination with amphotericin B against environmental strains of Cryptococcus neoformans from northeastern Brazil: a prospective experimental study

BACKGROUND: Statins are used as cholesterol-lowering drugs and may also have direct antimicrobial effects. OBJECTIVE: To evaluate synergic interactions between simvastatin and both amphotericin B and fluconazole, against environmental strains of Cryptococcus neoformans isolated from captive birds' droppings. DESIGNAND SETTING: Experimental study conducted at Federal University of Piauí, Parnaíba, in collaboration with Federal University of Triângulo Mineiro, Uberaba, Brazil. METHODS: Statin susceptibility tests of Cryptococcus neoformans samples were performed as prescribed in standards. Interactions of simvastatin with amphotericin and fluconazole were evaluated using the checkerboard microdilution method. Presence of these interactions was quantitatively detected through determining the fractional inhibitory concentration index (FICI). RESULTS: Isolates of Cryptococcus neoformans were obtained from 30 of the 206 samples of dry bird excreta (14.5%) that were collected from pet shops and houses. Ten isolates were selected for susceptibility tests. All of them were susceptible to amphotericin and fluconazole. All presented minimum inhibitory concentration (MIC) > 128 µg/ml and, thus, were resistant in vitro to simvastatin. An in vitro synergic effect was shown through combined testing of amphotericin B and simvastatin, such that six isolates (60%) presented FICI < 0.500. Two isolates showed considerable reductions in MIC, from 1 µg/ml to 0.250 µg/ml. No synergic effect was observed through combining fluconazole and simvastatin. CONCLUSION: These results demonstrate that simvastatin should be considered to be a therapeutic alternative, capable of potentiating the action of amphotericin B. However, further studies are necessary to clarify the real effect of simvastatin as an antifungal agent.

Diabetes as a risk factor of acute kidney injury in vancomycin users: an observational and prospective study

Diabetes was investigated as a risk factor for nephrotoxicity induced by vancomycin. In the present study, the drug's nephrotoxic effect was indirectly evaluated by Glomerular Filtration Rate, albuminuria and serum levels of creatinine and urea on the 1st, 7th and 14th days of vancomicyn therapy in a group of diabetic and non-diabetic patients, with and without previous nephropathy. The correlations between investigated variables (including the population's epidemiological profile and hospital care) were measured by the Spearman test. The sample consisted of 132 patients, predominantly male diabetic patients with previous nephropathy, over 40 years, receiving ≥ 10 grams of vancomycin for the treatment of infectious diseases and showing satisfactory clinical outcomes. A risk of vancomycin drug interaction with potential nephrotoxic outcome was observed in 36.4% of patients who used multiple drugs. Furthermore, 80% of patients had an increase of at least 0.5 mg.dL-1 in baseline serum levels of creatinine and urea at the end of the study. This was more common among the diabetic patients with previous nephropathy, showing higher albuminuria and a reduction in the Glomerular Filtration Rate. Therefore, it has been recommended that the use of vancomycin in diabetic patients should be in careful dosages and that kidney functioning be monitored.

Agronomic and Economic Interactions between Sidedressed Nitrogen and Potassium Fertilizations on Atlantic Potato

Abstract Nitrogen (N) and potassium (K) in potato crop planting synergistically increase tuber yield, but there are no studies on this interaction in sidedressing. In two experiments with 'Atlantic' potato combinations of four N rates (0, 50, 100, and 150 kg ha-1) with four K2O rates (0, 100, 200, and 300 kg ha-1) were applied in sidedressing in a 4×4 factorial scheme with three replications in a completely randomized design. Adjacent commercial fields were sampled to economic comparisons with experimental results. Significant interaction between N and K sidedressing rates with tuber yields increase also was confirmed and classified as Liebig-synergism. Compared to the isolated N and K applications in sidedressing, joint N and K fertilizations, respectively, increases by 11% and 48% marketable tuber yields in the summer-fall experiment, and 12% and 7% in the spring experiment. Joint N and K applications as sidedressing was more profitable than planting fertilization, mainly at higher N and K rates. The response of specific gravity of 'Atlantic' potato tubers to the N and K sidedressing rates was mediated by interactions between edaphoclimatic conditions and inputs of N and K. The combined application of N and K sidedressing rates increased specific gravity in the summer-fall experiment, but had a negative effect in the spring experiment. Therefore, our results provide strong evidence that the fertilization management for potato crop in Brazil can be modified by applying higher amounts of N and K in sidedressing to match nutritional needs of the crop.

Synergistic antibacterial effect and mechanisms of dihydroartemisinin and cefuroxime incombination / 中国中药杂志

In this study, we explored the antibacterial effect and mechanism of dihydroartemisinin(DHA) combined with cefuroxime(CFX) or ampicillin against Escherichia coli. The minimum inhibitory concentration(MIC) of DHA, cefuroxime, and ampicillin against E. coli was 300,25,25 μmol·L~(-1), respectively, determined by broth microdilution method and 2,3,5-triphenyltetrazolium chloride(TTC) method. The minimum bactericidal concentration(MBC) was 25 μmol·L~(-1) for cefuroxime, above 600 μmol·L~(-1) for DHA. The fractional inhibitory concentration index(FICI) of DHA combined with cefuroxime or ampicillin was 0.375 and 0.75, respectively, determined by checkerboard microdilution assay, suggesting the synergistic effect or additive effect of the drug combination. Moreover, the time-effect curve showed that the antibacterial activity of DHA and CFX combination was much stronger than that of either of the drugs, suggesting that combination with DHA can decrease the CFX dosage. Then we studied the synergistic mechanism of DHA combined with cefuroxime and found that the combination of the two drugs had a significant inhibitory effect on the total protein bands, as shown by the results of polypropylene gel electrophoresis. The results of conductivity method and alkaline phosphatase test respectively showed that its conductivity value and alkaline phosphatase(AKP) leak were significantly higher than either of the drugs, suggesting that the integrity of bacteria may be damaged. The scanning electron microscope(SEM) results showed that the morphology of E. coli was destroyed most in the combination group. The quantitative fluorescence PCR technology showed that the combination of two drugs can inhibit the expression of superoxide stress gene soxS. In summary, the combination of dihydroartemisinin and cefuroxime has a synergistic antibacterial effect on E. coli.

Therapeutic synergism: How can psychopharmacology improve cognitive rehabilitation? / Sinergismo terapêutico: como a psicofarmacologia pode melhorar a reabilitação cognitiva?

ABSTRACT Despite recent advances in cognitive rehabilitation of patients with cognitive disorders, there are many major obstacles to the optimized global use of this therapeutic resource. Objective: The authors outline the concept of 'therapeutic synergism', i.e. the concurrent use of pharmacological and cognitive rehabilitation therapies to maximize functional benefits, addressing the optimization of therapeutic approaches for cognitive disorders. Methods: Three psychopharmacological and rehabilitation interrelationship paradigms are presented in three different clinical settings. Results: Paradigm 1: Behavioral and cognitive symptoms that hinder a cognitive rehabilitation program, but can be improved with psychopharmacology. Paradigm 2: Cognitive symptoms that hinder cognitive rehabilitation, but can be improved with anticholinesterases. Paradigm 3: Behavioral symptoms that hamper the use of cognitive rehabilitation, but can be improved by psychotropic drugs. Conclusion: Judicious use of psychotropic drugs in cognitive disorders can benefit, directly or indirectly, cognitive functions, thereby favoring other treatment modalities for cognitive impairment, such as neuropsychological rehabilitation.

RESUMO Apesar dos recentes avanços na reabilitação cognitiva de pacientes com distúrbios cognitivos, existem muitos e graves obstáculos ao uso otimizado globalmente desse recurso terapêutico. Objetivo: Os autores destacam o conceito de 'sinergismo terapêutico', ou seja, o uso simultâneo de terapias de reabilitação farmacológica e cognitiva, maximizando os benefícios funcionais, a fim de abordar a otimização da abordagem terapêutica dos distúrbios cognitivos. Métodos: Três paradigmas de inter-relacionamento psicofarmacológico e de reabilitação são apresentados em três contextos clínicos diferentes. Resultados: Paradigma 1: sintomas comportamentais e cognitivos que dificultam um programa de reabilitação cognitiva, mas podem ser melhorados com a psicofarmacologia. Paradigma 2: sintomas cognitivos que dificultam a reabilitação cognitiva, mas podem ser melhorados com anticolinesterásicos. Paradigma 3: sintomas comportamentais que dificultam o uso da reabilitação cognitiva melhorada por drogas psicotrópicas. Conclusão: O uso criterioso das drogas psicotrópicas nos distúrbios cognitivos pode beneficiar, direta ou indiretamente, as funções cognitivas, favorecendo, portanto, outras modalidades de tratamento para o comprometimento cognitivo, como a reabilitação neuropsicológica.

Eficacia de las combinaciones antimicrobianas para el tratamiento de infecciones enterocócicas: una revisión crítica / Effectiveness of the antibiotic combinations for enterococcal infections treatment: a critical review

Resumen Durante las últimas décadas, especies del género Enterococcus han emergido como importantes agentes etiológicos de bacteriemia, osteomielitis, endocarditis e infecciones de tejidos blandos. La combinación de antibacterianos ha sido la estrategia terapéutica más utilizada para dichas infecciones, buscando un potencial efecto sinérgico bactericida. Sin embargo, aparte de los modelos in vitro e in vivo, la utilidad clínica del tratamiento combinado genera controversia, especialmente en infecciones sistémicas no endocárdicas. Aunque las combinaciones entre β-lactámicos y aminoglucósidos o el tratamiento dual con β-lactámicos, han mejorado las tasas de curación de la endocarditis, aún no se ha esclarecido cuál es su tratamiento óptimo o si estas combinaciones también son útiles en otro tipo de infecciones graves sistémicas. El propósito de esta revisión es analizar y resumir los resultados obtenidos de diferentes modelos experimentales de combinaciones anti-enterocócicas y de los estudios clínicos disponibles en PubMed/Medline, a fin de evaluar mejor la evidencia que soporta la utilización de estas combinaciones. En conclusión, la información disponible es escasa, e indica la necesidad de mejores modelos in vivo y estudios clínicos que permitan comprobar la potencial actividad sinérgica de las combinaciones anti-enterocóciccas.

During the last decades, enterococci have emerged as important etiological agents in bacteremia, osteomyelitis, endocarditis and soft tissue infections. Antimicrobial combinations have been the most used therapeutic strategies for these infections, aiming for a bactericidal synergistic effect. However, besides in vitro and in vivo models, the clinical usefulness of such combinations is controversial, especially in non-endocardic systemic infections. For example, although beta-lactam and aminoglycoside combinations or double beta-lactam treatment have achieved high cure rates in endocarditis, the optimal treatment has not yet been clarified or if these combinations are useful in other infections. The aim of this review was to analyze and summarize the results from several experimental models of antienterococcal combined therapy and from clinical trials available in PubMed/Medline, to better assess the evidence that supports the use of these combinations. In conclusion, the available information is scarce, and more and better in vivo models and clinical studies are required to confirm the potential synergistic activity of antienterococcal combinations.

Estudio comparativo de la bioactividad de dos materiales biocerámicos / Comparative Study of the Bioactivity of Two Bioceramic Materials

RESUMEN Los materiales a base de silicato de calcio han demostrado ser bioactivos debido a su capacidad para producir apatita carbonatada biológicamente compatible. El objetivo de este estudio fue analizar la bioactividad de Biodentine™ y MTA Repair HP® en contacto con discos de dentina humana, que se obturaron y dividieron aleatoriamente para formar cuatro grupos: grupo 1 Biodentine™, grupo 2 MTA Repair HP®, grupo control positivo MTA Angelus® y grupo control negativo IRM®, los cuales se incubaron en solución PBS durante 10 días, para posterior análisis por medio de MEB-EDS y Espectroscopía Raman. Los tres materiales a base de silicato de calcio analizados en este estudio demostraron ser bioactivos pues al entrar en contacto con una solución a base de fosfato desencadenaron la precipitación inicial de fosfato de calcio amorfo, que actúa como precursor durante la formación de apatita carbonatada.

ABSTRACT Calcium silicate-based materials have been shown to be bioactive due to their ability to produce biologically compatible carbonated apatite. The objective of this study was to analyze the bioactivity of Biodentine ™ and MTA Repair HP® in contact with human dentine discs, which were sealed and divided randomly to form four groups: group 1 Biodentine™, group 2 MTA Repair HP®, positive control group MTA Angelus® and negative control group IRM®, which were incubated in PBS solution for 10 days, for a subsequent analysis by means of MEB-EDS and Raman spectroscopy. The three calcium-based materials analyzed in this study proved to be bioactive because upon contact with a phosphate-based solution they were triggered at the onset of amorphous calcium phosphate, as the precursor during the formation of carbonated apatite.

Astemizole, an inhibitor of ether-à-go-go-1 potassium channel, increases the activity of the tyrosine kinase inhibitor gefitinib in breast cancer cells

Abstract Background Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression. Objective We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells. Materials and Methods The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cytometry. Results Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle. Conclusions Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.

Efeito combinado de carvacrol e tiabendazol contra Colletotrichum gloesporioides, Fusarium solani e Alternaria alternata / Combined effect of carvacrol and thiabendazole against Colletotrichum gloesporioides, Fusarium solani and Alternaria alternata

O objetivo deste trabalho foi determinar a atividade antimicrobiana do carvacrol e sua combinação com tiabendazol no controle de fungos patogênicos deteriorantes de frutas (Colletotrichum gloesporioides, Fusarium solani e Alternaria alternata). O carvacrol apresentou uma concentração inibitória mínima (CIM) de 282 a 563 μg mL-1 para os fungos testados. Quando avaliado em conjunto com o tiabendazol apresentou efeito aditivo contra C. gloesporioides e F. solani (FICI 0,5 e 1,0, respectivamente) e sinérgico contra a A.alternata (FICI 0,1). Houve redução da CIM do carvacrol de 50 a 88%. Este estudo mostra o potencial do uso.

Sinergismo de óleos essenciais sobre endósporos de Clostridium sporogenes / Essential oils sinergisms on Clostridium sporogenes endospores

A forma mais comum de inibir a produção de toxina botulínica em produtos cárneos cozidos é pela adição de sais de nitrito, o que pode gerar substâncias carcinogênicas (nitrosaminas), sendo desejável sua substituição. Os óleos essenciais vêm se destacando como agentes antimicrobianos, sendo interessante seu uso como conservante. O objetivo desse trabalho foi avaliar a ação sinergística de óleos essenciais sobre endósporos de Clostridium sporogenes, utilizado como modelo de pesquisa para C. botulinum. As concentrações mínimas esporicidas (CME) dos óleos de alecrim, tomilho, cravo, manjericão, ho wood e alho foram de 3% e de 0,375% para pimenta e canela. Os óleos de orégano e noz moscada não apresentaram ação esporicida nas concentrações testadas. Entre as combinações, as melhores foram de pimenta chinesa (0,1306%), alho (1,1%) e manjericão (1,1%) e pimenta chinesa (0,1306%), alho (1,1%) e tomilho branco (1,1%). Os resultados sugerem o sinergismo entre os óleos, sendo promissor seu uso em alimentos.