Antimicrobial potential of a biosurfactant gel for the prevention of mixed biofilms formed by fluconazole-resistant C. albicans and methicillin-resistant S. aureus in catheters.

Dual-species biofilms formed by Candida albicans and Staphylococcus aureus have high virulence and drug resistance. In this context, biosurfactants produced by Pseudomonas aeruginosa have been widely studied, of which a new derivative (RLmix_Arg) stands out for possible application in formulations. The objective of this study was to evaluate the antibiofilm activity of RLmix_Arg, both alone and incorporated in a gel prepared with Pluronic F-127, against dual-species biofilms of fluconazole-resistant C. albicans (FRCA) and methicillin-resistant S. aureus (MRSA) in impregnated catheters. Broth microdilution tests, MTT reduction assays of mature biofilms, impregnation of RLmix_Arg and its gel in peripheral venous catheters, durability tests and scanning electron microscopy (SEM) were performed. RLmix_Arg showed antimicrobial activity against Candida spp. and S. aureus, by reducing the cell viability of mixed biofilms of FRCA and MRSA, and preventing their formation in a peripheral venous catheter. The incorporation of this biosurfactant in the Pluronic F-127 gel considerably enhanced its antibiofilm activity. Thus, RLmix_Arg has potential application in gels for impregnation in peripheral venous catheters, helping to prevent development of dual-species biofilms of FRCA and MRSA.

Promising activity of etomidate against mixed biofilms of fluconazole-resistant Candida albicans and methicillin-resistant Staphylococcus aureus.

Introduction. Candida albicans and Staphylococcus aureus are recognized for their development of resistance and biofilm formation. New therapeutic alternatives are necessary in this context.Hypothesis. Etomidate shows potential application in catheters against mixed biofilms of fluconazole-resistant C. albicans and methicillin-resistant S. aureus (MRSA).Aim. The present study aimed to evaluate the activity of etomidate against mixed biofilms of fluconazole-resistant C. albicans and MRSA.Methodology. The action of etomidate against mature biofilms was verified through the evaluation of biomass and cell viability, and its ability to prevent biofilm formation in peripheral venous catheters was determined based on counts of colony forming units (c.f.u.) and confirmed by morphological analysis through scanning electron microscopy (SEM).Results. Etomidate generated a reduction (P<0.05) in biomass and cell viability starting from a concentration of 250 µg ml-1. In addition, it showed significant ability to prevent the formation of mixed biofilms in a peripheral venous catheter, as shown by a reduction in c.f.u. SEM revealed that treatment with etomidate caused substantial damage to the fungal cells.Conclusion. The results showed the potential of etomidate against polymicrobial biofilms of fluconazole-resistant C. albicans and MRSA.

Alterações neuroquímicas, comportamentais e histológicas promovidas pela cocaína isoladamente e em associação com imipramina, topiramato e pentoxifilina em ratos [manuscrito] / Neurochemical, behavioral and histological changes introduced by cocaine alone and in combination with imipramine, topiramate and pentoxifylline in rats [manuscript]

A cocaína é reconhecida por produzir marcantes alterações sobre o humor e comportamento humanos. Este trabalho teve como objetivo estudar as alterações neuroquímicas, comportamentais e histopatológicas providos pela administração repetida (7 dias) de cocaína isoladamente ou em associação com imipramina, um antidepressivo tricíclico, topiramato, um antiepiléptico, e pentoxifilina, um vasodilatador, em ratos. Ratos Wistar machos (200-250 g) foram tratados diariamente com cocaína isoladamente (Coc, 10 e 20 mg/kg, i.p.) ou em associação com imipramina (Imi, 12,5 ou 2,5 mg/kg, v.o.), topiramato (TPM, 50 mg/kg, v.o.), pentoxifilina (Pent, 50 mg/kg, i.p.) durante 7 dias. Cocaína causou um aumento significativo da atividade locomotora, e sua combinação com Imipramina, topiramato e pentoxifilina bloqueou os efeitos promovidos pela cocaína. No teste de esquiva passiva, a cocaína reduziu a memória de curto e de longo prazo enquanto que a imipramina reverteu parcialmente os efeitos da cocaína. Pentoxifilina bloqueou completamente os efeitos da cocaína. No labirinto aquático, a cocaína aumentou o tempo para encontrar a plataforma, efeito revertido totalmente pela imipramina e pentoxifilina e parcialmente pelo topiramato. No teste de labirinto em cruz elevada, cocaína e imipramina diminuíram o número de entradas e o tempo de permanência nos braços abertos...

Cocaetileno um metabolito da associaçäo cocaina e etanol / Cocaethylene a metabolite of cocaine and ethanol association

A cocaina, droga psicoestimulante, e usada frequentemente em associacao com outras drogas de abuso (alcool, heroina, sedativos, maconha, entre outras). Entre estas, o consumo simultaneo de cocaina e alcool tem aumentado significativamente nos ultimos anos em todo o mundo. Com o objetivo de estudar a associacao entre essas drogas, foi realizada uma pesquisa bibliografica via Internet, utilizando programas de pesquisa cientifica (Pubmed e Lilacs), alem...