Soybean (Glycine max L) seed quality treated with timbó (Magonia pubescens A. St.-Hil) seed coat / Qualidade de sementes de soja (Glycine max L) tratadas com diasporo do tegumento de sementes de timbó (Magonia pubescens A. St.-Hil)

The objective of this study was to evaluate the effect of timbó seed coat on the physiological and sanitary quality of soybean seeds. Timbó seeds were collected from mature fruits in the Cerrado. The external layer of the seed coat was removed and crushed in a mill and used in the treatment of soybean seeds. Three lots of soybean seeds were used, from high, medium and low vigor seeds. The treatments were: powder; gel; hydroalcoholic extract; synthetic fungicide (Vitavax® - Thiram 200 sc), and untreated seeds. The physiological quality of the soybean seeds was determined by standard germination, accelerated aging, length, fresh and dry mass of seedlings. Blotter test was used to determine the sanitary quality. The statistical analyze used was a completely randomized 3 × 5 factorial design, considering three seed lots and five treatments. Treatment with the coat seed extract and gel improves the physiological quality of soybean seeds from low vigor lots. The treatment of seeds with gel decreases the incidence of Fusarium and Penicillium genus; and treatment with the powder reduced the incidence of the Cercospora genus.(AU)

O objetivo deste estudo foi avaliar o efeito do tegumento das sementes de timbó sobre a qualidade fisiológica e sanitária de sementes de soja. As sementes de timbó foram coletadas de frutos maduros, no Cerrado. A camada mais externa do tegumento das sementes foi retirada e triturada em moinho e utilizada no tratamento de sementes de soja. Foram utilizados três lotes de sementes de soja, provenientes de sementes de alto, médio e baixo vigor. Os tratamentos foram: pó, gel, extrato hidroalcoólico; fungicida sintético (Vitavax® - Thiram 200 sc) e sementes não tratadas. A qualidade fisiológica das sementes de soja foi determinada pelo teste padrão de germinação, envelhecimento acelerado, comprimento, massa fresca e seca de plântulas. Para a determinação da qualidade sanitária utilizou-se o teste de borrão (blotter test). O delineamento estatístico foi em esquema fatorial 3 × 5, inteiramente casualizado, considerando-se três lotes de sementes e cinco tratamentos. Os tratamentos com o extrato e o gel do tegumento das sementes de timbó melhoraram a qualidade fisiológica das sementes de soja provenientes de lotes de baixo vigor. O tratamento com gel do tegumento das sementes de timbó diminuiu a incidência de fungos dos gêneros Fusarium e Penicillium; e o tratamento com o pó reduziu a incidência do gênero Cercospora.(AU)

Antifungal and Antioxidant Activities of Vernonia Chalybaea Mart. ex DC. Essential Oil and their Major Constituent β -caryophyllene

Abstract: This article describes the chemical composition of Vernonia chalybaea essential oil, and investigates its antimicrobial, antioxidant and hemolytic activities. The evaluation of the antifungal activity was performed by the broth microdilution method using strains of yeasts and dermatophytic fungi. The checkerboard technique to find antimicrobial modulatory effects was performed using ketoconazole as standard drug. The antioxidant activity was evaluated by DPPH scavenging assay and β-carotene/linoleic-acid system. The toxicity was characterized by the brine shrimp lethality test and hemolysis bioassays. The essential oil was obtained by hydrodistillation and analyzed by GC-MS method, showing to be rich in the sesquiterpenes β-caryophyllene (39.06%) and bicyclogermacrene (19.69%), and also demonstrated a relevant antifungal activity against strains of Trichophyton rubrum. In the modulatory activity assay, the essential oil of V. chalybaea and β-caryophyllene demonstrated a synergistic interaction with ketoconazole, with increasing of its antifungal action. The antioxidant activity was evidenced mainly by β-carotene/linoleic acid system, with IC50 value of 35.87 ± 0.32 µg/mL. The results suggest that V. chalybaea essential oil and β-caryophyllene are valuable natural medicinal agents with antioxidant and antimicrobial activities.

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.

A 12-year study of fungal infections in Rio Grande do Sul, southern Brazil

Background: The number of fungal infections has increased in recent years in Rio Grande do Sul (RS), Brazil. Epidemiological studies are important for proper control of infections. Aims: To evaluate the etiology of fungal infections in patients in RS, from 2003 to 2015. Methods: This is a retrospective and longitudinal study carried out at Mycology Department of Central Laboratory of RS; 13,707 samples were evaluated. The variables sex, age, site of infection, and etiologic agent were analyzed. Susceptibility of Candida to fluconazole was tested in samples collected in 2015from 51 outpatients. Results: Of the 13,707 samples, 840 cases (6.12%) of fungal infections were found and included in the analyses; female gender accounted for the 55.9% of the cases. The main fungus was Candida albicans (450 cases, 53.38%; p < 0.001). Onychomycosis was the most frequent infection in superficial mycoses. Systemic mycoses accounted for 54.05% of the cases, from which 68.8% occurred in males, mainly HIVpositive (33.11%), and the main etiologic agent in these cases was Cryptococcus neoformans (73.13%). Among 51 samples tested for susceptibility to fluconazole, 78.43% of Candida isolates were susceptible; 5.88% were susceptible in a dose-dependent manner, and 15.69% were resistant. Conclusions: C. albicans is a common cause of fungal infections in RS, accounting for half of the cases;resistance to antifungals was found in non-hospitalized patients. In addition, women seem to be moresusceptible to fungal infections than men, however men show more systemic mycoses than women. Thenails are the most common site of infection. (AU)

Antifungal activity of nanoemulsions encapsulating oregano (Origanum vulgare) essential oil: in vitro study and application in Minas Padrão cheese

ABSTRACT The objective of this study was to evaluate the antifungal activity of nanoemulsions encapsulating essential oil of oregano (Origanum vulgare), both in vitro and after application on Minas Padrão cheese. Nanodispersions were obtained by the phase inversion temperature method. Cladosporium sp., Fusarium sp., and Penicillium sp. genera were isolated from cheese samples and used to evaluate antifungal activity. Minimal inhibitory concentrations of non-encapsulated and encapsulated oregano essential oil were determined, and they were influenced by the encapsulation of the essential oil depending on the type of fungus. The antifungal activity of the nanoencapsulated oregano essential oil in cheese slices showed no evidence of an effect of the MICs, when applied in the matrix. On the other hand, an influence of contact time of the nanoemulsion with the cheese was observed, due to the increase in water activity. It was concluded that nanoencapsulated oregano essential oil presented an inhibitory effect against the three genera of fungi evaluated. If environmental parameters, such as storage temperature and water activity, were controlled, the inhibitory effect of nanoemulsions of oregano oil could possibly be greatly improved, and they could be presented as a potential alternative for the preservation of Minas Padrão cheese against fungal contamination.

Cotton vegetation indices under diffentent control methods of ramularia leaf spot / Indices de vegetação no algodoeiro sob diferentes fungicidas de controle da mancha da ramulária

This work aimed to correlate treatments using fungicides to different vegetation indices in response to effects caused by ramularia leaf spot (Ramularia areola). The experiment was carried out in the municipality of Chapadão do Sul, state of Mato Grosso do Sul, in the harvest 2016/2017, and consisted of a randomized blocks design, with 17 treatments and four replications. Data were obtained from the Sequoia 4.0 passive sensor and the Green Seeker LT 200 active sensor. From the information recorded by the sensors, nine vegetation indices were generated and compared with the area under the curve of disease progression, plant height, yield, and agronomic efficiency, in 17 different treatments of fungicide products. Treatments responded differently to the product applied. The SAVI index (Soil Adjusted Vegetation Index), obtained from the band in the red spectral range, presented higher correlation to AACPD, agronomic efficiency, and yield. The NDVI index (Normalized Difference Vegetation Index) had a higher correlation to plant height and SR (simple ratio), both using the wavelength in the red spectral range. (AU)

Este trabalho objetivou correlacionar diferentes índices de vegetação em resposta aos efeitos causados pela mancha de ramulária (Ramularia areola) de vários tratamentos com produtos fungicidas. O experimento foi implantado no município de Chapadão do Sul, Estado de Mato Grosso do Sul, no ano agrícola 2016/2017. O delineamento experimental utilizado foi blocos casualizados com 17 tratamentos com quatro repetições. Foram obtidos dados a partir do sensor passivo Sequoia 4.0 e do sensor ativo Green Seeker LT 200. A partir das informações registradas pelos sensores, foram gerados nove índices de vegetação, que foram comparados com a área abaixo da curva de progresso da doença, altura de plantas, produtividade e eficiência agronômica em 17 diferentes tratamentos de produtos de ação fungicida. Os tratamentos responderam de forma distinta em relação ao produto neles aplicados, sendo que os índices SAVI (Soil Adjusted Vegetation Index), obtidos a partir da banda na faixa espectral do Red, apresentaram maior correlação com AACPD, eficiência e produtividade. Já o índice NDVI (Normalized Difference Vegetation Index) obteve maior correlação com a altura de plantas e SR(Simple Ratio),ambosutilizando o comprimento de onda na faixa espectral da banda Red. (AU)

Drug susceptibility in emerging fungal infections: tests with fluconazole, itraconazole, and amphotericin B

Abstract: The number of new cases of emerging fungal infections has increased considerably in recent years, mainly due to the large number of immunocompromised individuals. The objective of this study was to evaluate the susceptibility of emerging fungi to fluconazole, itraconazole and amphotericin B by disk diffusion method. In 2015, 82 emerging fungi were evaluated in IPB-LACEN/RS and 13 (15.8%) were resistant: 10/52 were from superficial mycoses and 3/30 from systemic mycoses. The data from the study point to the need for permanent vigilance regarding the careful evaluation in the prescription and clinical and laboratory follow-up of patients affected by fungal infections.

Phytochemistry, antioxidant potential and antifungal of Byrsonima crassifolia on soil phytopathogen control / Fitoquímica, potencial antioxidante e antifúngico de Byrsonima crassifolia no controle de fitopatógenos de solo

Abstract The use of chemical defensives to control fungal diseases has by consequence to impact negatively over the environment and human health, this way, the use of plant extracts with antifungal properties along with proper cultural management makes viable an alternative plant production control, specially for familiar and organic cultures. The objective of this study was to perform phytochemical and antioxidant analysis of Byrsonima crassifolia (canjiqueira) barks and evaluate its antifungal potential over Fusarium solani and Sclerotinia sclerotiorum mycelial growth. The ethanol extract from plants collected in Pantanal, Mato Grosso do Sul, Brazil was submitted to phytochemical prospection, total phenol and flavonoids quantification and antioxidant activiy determination (DPPH). To evaluate antifungal activity concentrations of 800, 1200, 1600, 2000 and 2400 µg 100 mL-1 of ethanol extract were used. Which concentration was separately incorporated in agar (PDA) and shed in Petri dishes, followed by the fungi mycelial disc where the colonies diameter was measured daily. Negatives control with agar without extract and agar with an ethanol solution were used. The B. crassifolia ethanol extract presented inhibitory activity over the fungi studied where concentrations of 800 and 1600 µg 100 mL-1, inhibited 38% of the mycelial growth of F. solani; to S. sclerotiorum the best concentration was 2400 µg 100 mL1, reducing 37.5%. The antifungal bark extract potential of this specie is attributed to phenolic compounds and to triterpenes derivatives.

Resumo A aplicação de defensivos químicos para o controle de doenças fúngicas tem por consequência impactos sobre o ambiente e a saúde humana, dessa forma, a utilização de extratos vegetais com propriedades antifúngicas associado ao manejo adequado de culturas, torna-se uma proposta viável de controle alternativo, principalmente na agricultura orgânica e familiar. Neste sentido, objetivou-se neste trabalho realizar a análise fitoquímica e antioxidante das cascas de Byrsonima crassifolia (canjiqueira) e avaliar seu potencial antifúngico sobre o crescimento micelial de Fusarium solani e Sclerotinia sclerotiorum. O extrato etanólico das cascas da planta, coletadas no Pantanal do Rio Negro, em Mato Grosso do Sul, foi submetido à prospecção fitoquímica, quantificação de fenóis totais e flavonoides e determinação da atividade antioxidante (DPPH). Para a avaliação da atividade antifúngica foram utilizadas as concentrações de 800, 1200, 1600, 2000 e 2400 µg 100 mL-1 do extrato etanólico. Cada concentração foi incorporada, separadamente, em ágar BDA, e vertida em placas de petri, seguido do disco de micélio do fungo, onde o diâmetro das colônias foi medido diariamente. Utilizou-se como controle negativo, ágar sem extrato e ágar com solução etanólica. O extrato etanólico de B. crassifolia apresentou atividade inibitória sobre os fungos estudados, onde as concentrações de 800 e 1600 µg 100 mL-1, inibiram 38% do crescimento micelial de F. solani; para S. sclerotiorum, a melhor concentração foi de 2400 µg 100 mL1, com 37,5% de redução de crescimento. Atribui-se o potencial antifúngico do extrato da casca da espécie aos compostos fenólicos e derivados de triterpenos.

Non-viral microbial keratitis in adults: clinical and laboratory aspects

Abstract This study compares patients with and without non-viral microbial keratitis in relation to sociodemographic variables, clinical aspects, and involved causative agent. Clinical aspects, etiology and therapeutic procedures were assessed in patients with and without keratitis that were diagnosed in an Eye Care Center in Campo Grande, MS, Brazil. Patients were divided into two groups: (a) cases: 64 patients with non-viral microbial keratitis diagnosed at biomicroscopy; and (b) controls: 47 patients with other eye disorders that were not keratitis. Labor activity related to agriculture, cattle raising, and contact lens use were all linked to keratitis occurrence (p < 0.005). In patients with keratitis, the most common symptoms were pain and photophobia, and the most frequently used medicines were fourth-generation fluoroquinolones (34.4%), amphotericin B (31.3%), and natamycin (28.1%). Microbial keratitis evolved to corneal perforation in 15.6% of cases; transplant was indicated in 10.9% of cases. Regarding the etiology of this condition, 23 (42.2%) keratitis cases were caused by bacteria (Pseudomonas aeruginosa, 12.5%), 17 (39.1%) by fungi (Fusarium spp., 14.1% and Aspergillus spp., 4.7%), and 4 (6.3%) by Acanthamoeba. Patients with keratitis present with a poorer prognosis. Rapid identification of the etiologic agent is indispensable and depends on appropriate ophthalmological collection and microbiological techniques.

Antimicrobial potential of pyroligneous extracts - a systematic review and technological prospecting

Abstract Pyroligneous extract is applied in diverse areas as an antioxidant, an antimicrobial, and an anti-inflammatory agent. The discovery of new cost-effective antimicrobial agents of natural origin remains a challenge for the scientific community. This study aimed to conduct a systematic review and a technological forecasting of the existent evidence regarding the use of pyroligneous extract as a potential antimicrobial agent. Studies were identified through an investigation of various electronic databases: PubMed, SciFinder, Web of Science, Scopus, Scielo, Google scholar, and ProQuest. Patents were searched through INPI, Google patents, Espacenet, Patents online, USPTO, and WIPO. The literature on antimicrobial activity of pyroligneous extract are limited given the short duration of studies and variability in study design, use of pyroligneous preparations, and reports on results. However, evidence suggests the potential of pyroligneous extract as a natural antimicrobial agent. The most studied activity was the role of PE as a food preservative. However, pyroligneous extracts are also effective against pathogenic bacteria in the oral microflora and treatment of candidal infections. Further research is needed using standardized preparations of pyroligneous extracts to determine their long-term effectiveness and ability as antimicrobial agents.

Infección del torrente sanguíneo en pacientes receptores de trasplante de precursores hematopoyéticos. Siete años de experiencia con adultos y niños / Bloodstream infection in patients receiving hematopoietic stem cell transplant. Seven years of experience with adults and children

Resumen Introducción: La infección del torrente sanguíneo es una complicación usual, que puede comprometer la vida de los pacientes que recibieron trasplante de precursores hematopoyéticos. Objetivo: Analizar las características de las infecciones del torrente sanguíneo en receptores de trasplante de precursores hematopoyéticos. Materiales y Métodos: Estudio observacional, retrospectivo. Se revisaron los registros de 451 pacientes (trasplantes autólogos y alogénicos), desde enero de 2009 a octubre de 2015. Resultados: Hubo 99 hemocultivos positivos en 73 pacientes con infección del torrente sanguíneo (16%). Mortalidad atribuible a causas infecciosas: 17%. De las 99 infecciones sanguíneas, 63% fueron provocados por bacilos gramnegativos (Escherichia coli 45%, Klebsiella spp 23%, Pseudomonas spp 11%, Acinetobacter spp 6% y otros bacilos gramnegativos 15%), 33% por cocáceas grampositivas, 3% por hongos y 1% por bacilos grampositivos. Se observó resistencia a ciprofloxacina (81%), piperacilina/tazobactam (48%), Enterobacteriaceae productoras de β-lactamasa de espectro extendido (BLEE) (40%), cefepime (39%) y ausencia de resistencia a amikacina. Discusión: Existe mayor frecuencia de infección por bacilos gramnegativos, con un importante porcentaje de aislados multi-resistentes, y consecuente, alta resistencia al tratamiento antimicrobiano empírico.

Background: Bloodstream infection is a common complication, which can be life-threatening for hematopoietic stem cells transplant recipients. Objective: To analyze the characteristics of bloodstream infections in hematopoietic stem cell transplant recipients. Materials and Methods: Observational, retrospective study. We reviewed the records of 451 patients (autologous and allogeneic transplants) from January 2009 to October 2015. Results: 99 positive blood cultures in 73 patients with bloodstream infection (16%) were found. Mortality attributable to infectious causes was 17%. From the 99 bloodstream infection, 63% were caused by gram-negative bacilli (Escherichia coli 45%, Klebsiella spp 23%, Pseudomonas spp 11% Acinetobacter spp % and other bacilli 15%), 33% by gram-positive cocci, 3% by fungi and 1% by gram-positive bacilli. The gram-negative bacilli were ciprofloxacin resistant (81%), piperacillin/tazobactam resistant (48%), extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (40%), cefepime resistant (39%) and there was no resistance noted to amikacin. Discussion: There is a higher frequency of gram-negative bacilli infection, with a high percentage of multiresistant microorganisms and high resistance to empirical antibiotic treatment.

In vitro antifungal activity of organic compounds derived from amino alcohols against onychomycosis

Abstract Onychomycosis is a fungal infection of the nail caused by high densities of filamentous fungi and yeasts. Treatment for this illness is long-term, and recurrences are frequently detected. This study evaluated in vitro antifungal activities of 12 organic compounds derived from amino alcohols against standard fungal strains, such as Trichophyton rubrum CCT 5507 URM 1666, Trichophyton mentagrophytes ATCC 11481, and Candida albicans ATCC 10231. The antifungal compounds were synthesized from p-hydroxybenzaldehyde (4a-4f) and p-hydroxybenzoic acid (9a-9f). Minimum inhibitory concentrations and minimum fungicidal concentrations were determined according to Clinical and Laboratory Standards Institute protocols M38-A2, M27-A3, and M27-S4. The amine series 4b-4e, mainly 4c and 4e compounds, were effective against filamentous fungi and yeast (MIC from 7.8 to 312 µg/mL). On the other hand, the amide series (9a-9f) did not present inhibitory effect against fungi, except amide 9c, which demonstrated activity only against C. albicans. This allowed us to infer that the presence of amine group and intermediate carbon number (8C-11C) in its aliphatic side chain seems to be important for antifungal activity. Although these compounds present cytotoxic activity on macrophages J774, our results suggest that these aromatic compounds might constitute potential as leader molecules in the development of more effective and less toxic analogs that could have considerable implications for future therapies of onychomycosis.

Bioprospección de la actividad antimicrobiana de los extractos de los hongos endófitos de Bauhinia guianensis / Bioprospecting of antimicrobial activity of extracts of endophytic fungi from Bauhinia guianensis

Antibiotic resistance results in higher medical costs, prolonged hospital stays and increased mortality and is rising to dangerously high levels in all parts of the world. Therefore, this study aims to search for new antimicrobial agents through bioprospecting of extracts of endophytic fungi from Bauhinia guianensis, a typical Amazonian plant used in combating infections. Seventeen (17) fungi were isolated and as result the methanolic extract of the fungus Exserohilum rostratum showed good activity against the bacteria tested. The polyketide monocerin was isolated by the chromatographic technique, identified by NMR and MS, showing broad antimicrobial spectrum.

La resistencia a los antibióticos conduce a mayores costos médicos, hospitalizaciones prolongadas e incremento de la mortalidad, y está aumentando a niveles peligrosamente altos en todas partes del mundo. Este estudio tuvo como objetivo la búsqueda de nuevos agentes antimicrobianos a través de la bioprospección de extractos de hongos endófitos de Bauhinia guianensis, una planta amazónica típica, utilizada en la lucha contra problemas infecciosos. Fueron aislados 17 hongos; el extracto metanólico del hongo Exserohilum rostratum mostró buena actividad contra las bacterias probadas. Se aisló monocerina policétido por la técnica de cromatografía; este compuesto fue identificado por RM y EM, y mostró un amplio espectro antimicrobiano.

Sensibilidad in vitro de Trichoconiella padwickii a diversos principios activos usados como fungicidas en el cultivo del arroz / In vitro susceptibility of Trichoconiella padwickii to various active ingredients used as fungicides in the cultivation of rice

El objetivo de este trabajo fue evaluar in vitro la sensibilidad micelial de Trichoconiella padwickii a diferentes principios activos por medio del cálculo de la concentración inhibitoria media (CI50). Para ello se realizaron siembras de discos de inóculo en agar poroto con distintas concentraciones (0,1; 1; 10; 30, 50; 100 y 1.000 mg/l) de diversos fungicidas. A los 7 días se midió el diámetro de crecimiento de la colonia (cm). Los datos obtenidos se ajustaron a modelos de regresión no lineal. La sensibilidad se clasificó utilizando la escala de Edgington. Los resultados obtenidos demuestran que el patógeno es muy sensible a los productos que actúan sobre la cadena respiratoria (quinone outside inhibitors QoI y succinate dehydrogenase inhibitors SDHI) y la membrana celular (multisitio), y moderadamente sensible a los que interfieren en la división celular (metil benzimidazol carbamatos MBC), en la síntesis de ácidos nucleicos (fenilamidas PA) y en la transducción de la señal osmótica (actividad multisitio). Este trabajo es el primer antecedente sobre la sensibilidad in vitro de T. padwickii a principios activos fungicidas.

The aim of this study was to evaluate in vitro the mycelial susceptibility of Trichoconiella padwickii to different active ingredients through average median concentration IC50 calculation. Inoculum disks were seeded on bean agar at different concentrations (0.1; 1; 10; 30, 50; 100 and 1000 mg/l) of various fungicides. After seven days the colony diameter was measured. The data obtained were fitted to nonlinear regression models. Susceptibility was classified using the scale proposed by Edgington. The results show that the pathogen is very sensitive to products that act on the respiratory chain (quinone outside inhibitors QoI and succinate dehydrogenase inhibitors SDHI) and cell membrane (multi-site contact activity), and moderately sensitive to those products interfering with cell division (methyl benzimidazole carbamates MBC), synthesis of nucleic acids (phenylamides PA) and osmotic signal transduction (multi-site contact activity). This work is the first record on the sensitivity of T. padwickii.

Síntese de heteroaril oxazolinas e derivados triazólicos com potencial atividade biológica / Synthesis of heteroaryl oxazolines and triazolic derivatives with potential biological activity

Fungos no ambiente podem ser patogênicos ou oportunistas, dependendo da imunidade do hospedeiro. Existem várias espécies de fungos, por exemplo, Cândida albicans, Cryptococcus e Aspergillus. A primeira espécie fúngica pode ser tratada com o antifúngico fluconazol, que é um composto que contém anéis heterocíclicos 1,2,4-triazólicos. Além disso, existem cepas de fungos que são resistentes à terapia com fluconazol, que é o caso das Cândida krusei, Cândida tropicalis; entre outras. A busca por novos tratamentos envolve o desenvolvimento de novas moléculas sintéticas. Neste trabalho, sintetizamos uma biblioteca de compostos oxazolínicos e seus derivados 1,2,3-triazólicos. A atividade microbiológica foi avaliada contra 10 tipos de Cândida, 2 tipos de Cryptococcus e 2 tipos de Aspergillus. Além disso, foram feitos os testes de hemólise, citotoxicidade, combinações de drogas e permeabilidade de membrana. Os resultados sugerem um alto potencial terapêutico dos compostos e os propomos como potenciais novos antifúngicos

ungi in the environment may be pathogenic or opportunistic depending on the immune status of the host. There are several species of fungi, for example, Candida albicans, Cryptococcus and Aspergillus. The first fungal species can be treated with the antifungal fluconazole, which is a compound containing 1,2,4-triazole heterocyclic rings. In addition, there are strains of fungi that are resistant to fluconazole therapy, which is the case of Candida krusei, Candida tropicalis; among others. The search for new treatments involves the development of new synthetic molecules. In this work, we synthesized a library of oxazoline compounds and their 1,2,3-triazole derivatives. Microbiological activity was evaluated against 10 types of Candida, 2 types of Cryptococcus and 2 types of Aspergillus. In addition, hemolysis, cytotoxicity, drug combinations and membrane permeability were performed. The results suggest the high therapeutic potential of the compounds and we propose them as potential new antifungals

Terpinen-4-ol, tyrosol, and ß-lapachone as potential antifungals against dimorphic fungi

Abstract This study aimed to evaluate the in vitro antifungal activity of terpinen-4-ol, tyrosol, and β-lapachone against strains of Coccidioides posadasii in filamentous phase (n = 22) and Histoplasma capsulatum in both filamentous (n = 40) and yeast phases (n = 13), using the broth dilution methods as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these compounds. The mechanisms of action of these compounds were also investigated by analyzing their effect on cell membrane permeability and ergosterol synthesis. The MIC and MFCf these compounds against C. posadasii, mycelial H. capsulatum, and yeast-like H. capsulatum, were in the following ranges: 350-5720 µg/mL, 20-2860 µg/mL, and 40-1420 µg/mL, respectively for terpinen-4-ol; 250-4000 µg/mL, 30-2000 µg/mL, and 10-1000 µg/mL, respectively, for tyrosol; and 0.48-7.8 µg/mL, 0.25-16 µg/mL, and 0.125-4 µg/mL, respectively for β-lapachone. These compounds showed a decrease in MIC when the samples were subjected to osmotic stress, suggesting that the compounds acted on the fungal membrane. All the compounds were able to reduce the ergosterol content of the fungal strains. Finally, tyrosol was able to cause a leakage of intracellular molecules.

Is the emergence of fungal resistance to medical triazoles related to their use in the agroecosystems? A mini review

Abstract Triazole fungicides are used broadly for the control of infectious diseases of both humans and plants. The surge in resistance to triazoles among pathogenic populations is an emergent issue both in agriculture and medicine. The non-rational use of fungicides with site-specific modes of action, such as the triazoles, may increase the risk of antifungal resistance development. In the medical field, the surge of resistant fungal isolates has been related to the intensive and recurrent therapeutic use of a limited number of triazoles for the treatment and prophylaxis of many mycoses. Similarities in the mode of action of triazole fungicides used in these two fields may lead to cross-resistance, thus expanding the spectrum of resistance to multiple fungicides and contributing to the perpetuation of resistant strains in the environment. The emergence of fungicide-resistant isolates of human pathogens has been related to the exposure to fungicides used in agroecosystems. Examples include species of cosmopolitan occurrence, such as Fusarium and Aspergillus, which cause diseases in both plants and humans. This review summarizes the information about the most important triazole fungicides that are largely used in human clinical therapy and agriculture. We aim to discuss the issues related to fungicide resistance and the recommended strategies for preventing the emergence of triazole-resistant fungal populations capable of spreading across environments.

The use of chitosan in protecting wooden artifacts from damage by mold fungi

Background: Many buildings in Egypt e.g. museums, mosques and churches, do not possess controlled environments for minimizing the risks of damage of wooden artifacts due to the growth of fungi. Fungal damage usually appears as change in wood color, appearance of stains, and sometimes deformation of wooden surfaces. In this study we focused on the effect that some fungi exert on the properties of wooden artifacts and evaluated the effectiveness of different concentrations of chitosan on their protection against damage by mold fungi. Results: Samples were collected from different monuments and environments, and fungi growing on them were isolated and identified. The isolated Penicillium chrysogenum, Aspergillus flavus and /Aspergillus niger strains were used for the infestation of new pitch pine samples. The results revealed that the lightness of samples infected with any of the tested fungi decreased with increasing incubation times. XRD analysis showed that the crystallinity of incubated samples treated individually with the different concentrations of chitosan was lower than the crystallinity of infected samples. The crystallinity index measured by the first and the second method decreased after the first and second months but increased after the third and fourth months. This may due to the reducing of amorphous part by enzymes or acids produced by fungi in wooden samples. Conclusions: The growth of fungi on the treated wood samples decreased with increasing the concentration of chitosan. Hence, it was demonstrated that chitosan prevented fungal growth, and its use could be recommended for the protection of archeological wooden artifacts.

Endophytic fungus strain 28 isolated from Houttuynia cordata possesses wide-spectrum antifungal activity

Abstract The aim of this paper is to identify and investigate an endophytic fungus (strain 28) that was isolated from Houttuynia cordata Thunb, a famous and widely-used Traditional Chinese Medicine. Based on morphological methods and a phylogenetic analysis of ITS sequences, this strain was identified as Chaetomium globosum. An antifungal activity bioassay demonstrated that the crude ethyl acetate (EtOAc) extracts of strain 28 had a wide antifungal spectrum and strong antimicrobial activity, particularly against Exserohilum turcicum (Pass.) Leonard et Suggs, Botrytis cinerea persoon and Botrytis cinerea Pers. ex Fr. Furthermore, the fermentation conditions, extraction method and the heat stability of antifungal substances from strain 28 were also studied. The results showed that optimal antifungal activity can be obtained with the following parameters: using potato dextrose broth (PDB) as the base culture medium, fermentation for 4–8 d (initial pH: 7.5), followed by extraction with EtOAc. The extract was stable at temperatures up to 80 °C. This is the first report on the isolation of endophytic C. globosum from H. cordata to identify potential alternative biocontrol agents that could provide new opportunities for practical applications involving H. cordata.

Effects of different forms of nitrogen on rhizosphere microbial community structure of Eichhornia crassipes (Pontederiaceae)

AbstractRhizosphere microbial communities are important for phytoremediation, plant nutrition, health and metabolism. Many factors, including plant species, pH and nutritional factors influence rhizosphere microbiology. In this study, we analysed the effects of different forms of nitrogen on the structures of rhizosphere microbial communities of E. crassipes. Using a conventional culture method with special media, bacteria, actinobacteria and molds were cultured. We found that the numbers of bacteria were largely similar across the three culture conditions, while the numbers of actinobacteria and molds from the rhizosphere of E. crassipes cultured in NH4Cl solution were two orders of magnitude higher than those from the rhizospheres of plants cultured in distilled water and KNO3 solution. Using a culture-independent method of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) of 16S rDNA, we found that the form of nitrogen could influence the components of the rhizosphere microbial community. Pseudoxanthomonas, Enterobacter and Citrobacter were present in all of the samples cultured under the three different experimental conditions. The genus Reyranella was found only in samples cultured in KNO3 solution; Acinetobacter and Streptomyces were unique to samples cultured in NH4Cl solution, and Pseudomonas, Pseudacidovorax and Methylosinus were found only in samples cultured in distilled water. Pseudoxanthomonas and Acidovorax were the dominant genera in the rhizosphere microbial community of E. crassipes cultured in KNO3 solution, while Novosphingobium was the dominant genus in the sample cultured in a nitrogen-deficient medium. Our results provide a theoretical foundation for using E. crassipes as a phytoremediation plant and controlling the widespread distribution of E. crassipes around the world using principles of nutrient metabolism.

ResumenComunidades microbianas de la rizósfera son importantes para la fitorremediación, nutrición vegetal, salud y metabolismo. Muchos factores, incluyendo la especie de planta, el pH y los factores nutricionales influyen en la microbiología de la rizósfera. En este estudio, se analizaron los efectos de las diferentes formas del nitrógeno en la estructura de las comunidades microbianas de la rizósfera de E. crassipes. Mediante métodos de cultivo convencional con medios especiales se cultivaron: bacterias, actinobacterias y mohos. Se encontró que el número de bacterias era en gran parte similar a través de las tres condiciones de cultivo, mientras que el número de actinobacterias y mohos de la rizósfera de E. crassipes cultivadas en solución de NH4Cl era dos órdenes de magnitud superior a los de las rizósferas de plantas cultivadas en agua destilada y solución de KNO3. Utilizando un método de cultivo independiente de electroforesis en gel con gradiente de desnaturalización (PCR-DGGE) del ADNr 16S, se encontró que la forma de nitrógeno podría influir en los componentes de la comunidad microbiana de la rizósfera. Pseudoxanthomonas, Enterobacter y Citrobacter estaban presentes en todas las muestras cultivadas en las tres condiciones experimentales. El género Reyranella se encontró sólo en muestras cultivadas en solución de KNO3; Acinetobacter y Streptomyces eran las únicas muestras cultivadas en solución de NH4Cl, y Pseudomonas, Pseudacidovorax y Methylosinus se encontraron sólo en muestras cultivadas en agua destilada. Pseudoxanthomonas y Acidovorax eran los géneros dominantes en la comunidad microbiana de la rizósfera de E. crassipes cultivadas en solución de KNO3, mientras que Novos phingobium fue el género dominante en la muestra cultivada en un medio deficiente de nitrógeno. Nuestros resultados proporcionan una base teórica para el uso de E. crassipes como planta fitorremediadora y para controlar la distribución generalizada de E. crassipes en todo el mundo a través de los principios del metabolismo de nutrientes.