Investigation of powerful fungicidal activity of tetra-cationic platinum(II) and palladium(II) porphyrins by antimicrobial photodynamic therapy assays.

This manuscript reports enhanced antimicrobial photoinactivation using tetra-cationic porphyrins with peripheral platinum(II) and palladium(II) complexes against fungal dermatophyte strains. Six different positively charged porphyrins were used and applied in antimicrobial photodynamic therapy experiments (aPDT) against dermatophyte fungi colonies. The microbiological tests were conducted with an adequate concentration of photosensitizer (PS) under white-light irradiation for 120 min and the most effective PS meta isomer 3PtP significantly reduced the concentration of viable fungal colony. In this way, tetra-cationic porphyrins containing platinum(II)-bipyridyl complexes may be promising fungicidal aPDT agents with potential applications in future clinical cases.

Novel Alkyl(aryl)-Substituted 2,2-Difluoro-6-(trichloromethyl)-2H-1,3,2-oxazaborinin-3-ium-2-uides: Synthesis, Antimicrobial Activity, and CT-DNA Binding Evaluations.

The synthesis, antimicrobial activity evaluations, biomolecule-binding properties (DNA), and absorption and emission properties of a new series of (Z)-1,1,1-trichloro-4-alkyl(aryl)amino-4-arylbut-3-en-2-ones (4, 5) and 2,2-difluoro-3-alkyl(aryl)amino-4-aryl-6-(trichloromethyl)-2H-1,3,2-oxazaborinin-3-ium-2-uides (6, 7) in which 3(4)-alkyl(aryl) = H, Me, iso-propyl, n-butyl, C6H5, 4-CH3C6H4, 4-CH3OC6H4, 4-NO2C6H4, 4-FC6H4, 4-BrC6H4, 2-naphthyl, is reported. A series of ß-enaminoketones (4, 5) is synthesized from the O,N-exchange reaction of some amines (3) with (Z)-1,1,1-trichloro-4-methoxy-4-aryl-but-3-en-2-ones (1, 2) at 61-90% yields. Subsequently, reactions of the resulting ß-enaminoketones with an appropriate source of boron (BF3.OEt2) gave the corresponding oxazaborinine derivatives (6, 7) at 50-91% yields. UV-Vis and emission properties of biomolecule-binding properties for the DNA of these new BF2-ß-enamino containing CCl3 units were also evaluated. Some compounds from the present series also exhibited potent antimicrobial effects on various pathogenic microorganisms at concentrations below those that showed cytotoxic effects. Compounds 4d, 4e, 6e, and 6f showed the best results and are very significant against P. zopfii, which causes diseases in humans and animals.

Antifungal susceptibility profile of Aspergillus fumigatus isolates from avian lungs / Perfil de suscetibilidade antifúngica de isolados de Aspergillus fumigatus provenientes de pulmões de aves

Susceptibility testing is essential to inform the correct management of Aspergillus infections. In this study we present antifungal susceptibility profile of A. fumigatus isolates recovered from lungs of birds with and without aspergillosis. Fifty three isolates were tested for their antifungal susceptibility to voriconazole (VRC), itraconazole (ITZ), amphotericin (AMB) and caspofungin (CSP) using the M38-A2 broth microdilution reference method. Five isolates were resistant to more than one antifungal drug (CSP + AMB, VRC + ITZ and AMB + ITZ). Fifteen (28%) isolates with susceptible increased exposure (I) to ITZ were sensible to VRC. Resistance to AMB (>2µg/mL) was observed in only four isolates. Eleven (21%) A. fumigatus present resistance to ITZ (13%) and VRC (8%). Fungal isolation from respiratory samples has been regarded as being of limited usefulness in the ante mortem diagnosis of aspergillosis in birds. However, the results suggest that the detection and antifungal susceptibility profile may be helpful for monitoring of therapy for avian species and where antifungal resistance might be emerging and what conditions are associated to the event.(AU)

Os testes de suscetibilidade são essenciais para informar o correto manejo das infecções por Aspergillus. Neste estudo apresentamos o perfil antifúngico de isolados de A. fumigatus provenientes de pulmões de aves com e sem aspergilose. Cinqüenta e três isolados foram testados quanto à susceptibilidade antifúngica ao voriconazol (VRC), itraconazol (ITZ), anfotericina B (AMB) e caspofungina (CSP) pelo método de referência de microdiluição do caldo M38-A2. Cinco isolados foram resistentes a mais de um antifúngico (CSP + AMB, VRC + ITZ e AMB + ITZ). Quinze (28%) isolados suscetíveis - com exposição aumentada (I) ao ITZ foram sensíveis ao VRC. A resistência ao AMB (>2µg/mL) foi observada em apenas quatro isolados. Onze (21%) A. fumigatus apresentaram resistência a ITZ (13%) e VRC (8%). O isolamento de fungos de amostras respiratórias tem sido considerado de utilidade limitada no diagnóstico ante mortem de aspergilose em aves. No entanto, os resultados sugerem que a detecção e o perfil de suscetibilidade a antifúngicos podem ser úteis para o monitoramento da terapia de espécies aviárias, assim como a emergência da resistência antifúngica e quais condições podem estar associadas ao evento.(AU)

Formulation and in vitro evaluation of coconut oil-core cationic nanocapsules intended for vaginal delivery of clotrimazole.

The objective of this work was to propose coconut oil-core nanocapsules prepared from Eudragit(®) RS100, a cationic polymer, and to evaluate their potential for vaginal delivery of clotrimazole in candidiasis. Nanocapsule suspensions loaded with clotrimazole at 1.0 and 3.0mg/mL were prepared by interfacial deposition of Eudragit(®) RS100. The physicochemical characterization showed average diameter lower than 200 nm, low polydispersity index, positive zeta potential (+10.94 to +14.57 mV), acid pH values (5.4-5.7) and encapsulation efficiencies close to 100%. After 60 days of storage at room temperature and protected from light, the nanocapsules were reasonably stable. Photodegradation studies showed that nanoencapsulation improved clotrimazole stability against UV radiation. The in vitro drug release at pH 4.5 was characterized by a prolonged release with no burst effect. The nanocapsules were more active than free clotrimazole against Candida albicans and Candida glabrata strains susceptible and resistant to fluconazole. Hence, clotrimazole-loaded coconut oil-core nanocapsules represent promising alternatives to the treatment of vulvovaginal candidiasis.

Synergysm of voriconazole or itraconazole with other antifungal agents against species of Fusarium

Antecedentes: Las micosis causadas por Fusarium son difíciles de tratar porque tanto in vivo como in vitro estos hongos muestran resistencia a casi todos los fármacos antimicóticos disponibles, lo que explica las altas tasas de mortalidad. Una tentativa de resolver la resistencia fúngica es combinar los fármacos antifúngicos, en especial los preparados con mecanismos de acción diferentes. Objetivos: Valorar las interacciones in vitro de la combinación de voriconazol o itraconazol con otros fármacos antimicóticos frente a 32 aislamientos de Fusarium spp: Fusarium chlamydosporum, Fusarium oxysporum, Fusarium proliferatum y Fusarium solani. Métodos: Las interacciones farmacológicas se valoraron con el método de microdilución en tablero de ajedrez, que también incluyó la determinación de la concentración inhibitoria mínima de cada fármaco por separado de acuerdo con el documento M38-A2, 2008, del Clinical and Laboratory Standards Institute. Resultados: Las mejores combinaciones fueron voriconazol + terbinafina que mostró sinergia frente al 84% de los aislamientos de Fusarium. Otras combinaciones sinérgicas fueron: voriconazol + itraconazol (50%), voriconazol + fluconazol (50%), voriconazol + miconazol (38%), voriconazol + flucitosina (22%) y voriconazol + ketoconazol (25%). Las sinergias observadas con las combinaciones de itraconazol fueron itraconazol + terbinafina (25%), e itraconazol + flucitosina (9,37%). Los antagonismos observados fueron voriconazol + fluconazol (3%) e itraconazol + flucitosina (12,5%). Conclusiones: La sinergia observada con voriconazol + terbinafina fue extraordinaria. Para dilucidar mejor la utilidad potencial de los hallazgos del presente estudio, han de realizarse nuevos estudios tanto in vivo como in vitro (AU)

Background. Infections caused by Fusarium are difficult to treat because these fungi show in vitro and in vivo resistance to practically all the antifungal agents available, which explains the high mortality rates. An attempt to overcome fungal resistance is the combination of antifungal agents, especially those with different mechanisms of action. Aims. Evaluate the in vitro interactions of combinations of voriconazole or itraconazole with other antifungal agents against 32 isolates of Fusarium spp.: Fusarium chlamydosporum, Fusarium oxysporum, Fusarium proliferatum and Fusarium solani. Methods. Drug interactions were assessed by a checkerboard microdilution method that also included the determination of the MIC of each drug alone according to CLSI (Clinical and Laboratory Standards Institute) document M38-A2, 2008. Results. The best combinations were voriconazole + terbinafine which showed synergism against 84% of Fusarium strains. Other synergistic combinations were voriconazole + itraconazole (50%), voriconazole + fluconazole (50%), voriconazole + miconazole (38%), voriconazole + flucytosine (22%) and voriconazole + ketoconazole (25%). The synergisms observed with itraconazole combinations were itraconazole + terbinafine (25%) and itraconazole + flucytosine (9.37%). The antagonisms observed were: voriconazole + fluconazole (3%) and itraconazole + flucytosine (12.5%). Conclusions. The synergism showed by voriconazole + terbinafine was remarkable. To better elucidate the potential usefulness of our findings, new in vivo and in vitro studies deserve be performed (AU)

Clotrimazole-loaded Eudragit® RS100 nanocapsules: preparation, characterization and in vitro evaluation of antifungal activity against Candida species.

Clotrimazole is a common choice for the treatment of vulvovaginal infections, but its low solubility and some side effects pose a challenge to its application. This work evaluated the feasibility to formulate clotrimazole-loaded cationic nanocapsules using Eudragit® RS100 and medium chain triglycerides as polymer and oily core, respectively, by the method of interfacial deposition of a preformed polymer. The physicochemical characteristics of nanocapsule formulations were evaluated at 0 day and 60 days after preparation. Particle size, zeta potential, polydispersity index, pH and drug content were stable during this period. In addition, nanocapsules were able to protect clotrimazole from photodegradation under UV radiation. By the dialysis bag diffusion technique, the nanosized formulations showed prolonged release of clotrimazole by anomalous transport and first order kinetics. A microbiological study was carried out by the microdilution method and showed that nanocapsules (mean size: 144 nm; zeta potential: +12 mV) maintained the antifungal activity of clotrimazole against Candida albicans and Candida glabrata strains susceptible and resistant to fluconazole.

Synergysm of voriconazole or itraconazole with other antifungal agents against species of Fusarium.

BACKGROUND: Infections caused by Fusarium are difficult to treat because these fungi show in vitro and in vivo resistance to practically all the antifungal agents available, which explains the high mortality rates. An attempt to overcome fungal resistance is the combination of antifungal agents, especially those with different mechanisms of action. AIMS: Evaluate the in vitro interactions of combinations of voriconazole or itraconazole with other antifungal agents against 32 isolates of Fusarium spp.: Fusarium chlamydosporum, Fusarium oxysporum, Fusarium proliferatum and Fusarium solani. METHODS: Drug interactions were assessed by a checkerboard microdilution method that also included the determination of the MIC of each drug alone according to CLSI (Clinical and Laboratory Standards Institute) document M38-A2, 2008. RESULTS: The best combinations were voriconazole+terbinafine which showed synergism against 84% of Fusarium strains. Other synergistic combinations were voriconazole+itraconazole (50%), voriconazole+fluconazole (50%), voriconazole+miconazole (38%), voriconazole+flucytosine (22%) and voriconazole+ketoconazole (25%). The synergisms observed with itraconazole combinations were itraconazole+terbinafine (25%) and itraconazole+flucytosine (9.37%). The antagonisms observed were: voriconazole+fluconazole (3%) and itraconazole+flucytosine (12.5%). CONCLUSIONS: The synergism showed by voriconazole+terbinafine was remarkable. To better elucidate the potential usefulness of our findings, new in vivo and in vitro studies deserve be performed.