Estudo do potencial antifúngico e do mecanismo de ação do timol contra cepas de Candida parapsilosis resistentes ao fluconazol e a anfotericina B / Study of the antifungal potential and mechanism of action of thymol against strains of Candida parapsilosis resistant to fluconazole and amphotericin B

Objetivo: investigar a suscetibilidade de cepas fúngicas de Candida parapsilosis isoladas de sangue humano frente ao timol, bem como seu mecanismo de ação. Metodologia: foram utilizadas técnicas de microdiluição em placas de 96 poços para determinar a concentração inibitória mínima (CIM) e concentração fungicida mínima (CFM). Além disso, foram realizados testes com o sorbitol e o ergosterol para investigar a ação do timol na parede e na membrana celular fúngica respectivamente. Resultados: nos testes de CIM e CFM, foi observado que as cepas de C. parapsilosis são resistentes ao fluconazol e a anfotericina B, no entanto, o timol desempenhou efeito fungicida com razão CFM/CIM entre 1 e 2. Além disso, a CIM do timol não aumentou quando o sorbitol ou o ergosterol foi adicionado no meio, sugerindo fortemente que este monoterpeno não age na parede celular fúngica ou por ligação ao ergosterol na membrana plasmática. Conclusão: portanto, esses resultados contribuem para a elucidação do mecanismo de ação do timol, sugerindo outros possíveis alvos de interação fármaco-receptor. No entanto, mais investigações de caráter enzimático e molecular em modelos in vitro são necessários para que se possa elucidar completamente o modo de ação desse promissor monoterpeno.

Objective: to investigate the susceptibility of fungal strains of Candida parapsilosis isolated from human blood against thymol, as well as its mechanism of action. Methodology: microdilution techniques were used in 96-well plates to determine minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). In addition, tests were performed with sorbitol and ergosterol to investigate the action of thymol on the wall and on the fungal cell membrane respectively. Results: in the CIM and CFM tests, it was observed that C. parapsilosis strains are resistant to fluconazole and amphotericin B, however, thymol had a fungicidal effect with MFC/MIC ratio between 1 and 2. In addition, thymol MIC did not increase when sorbitol or ergosterol was added in the medium, strongly suggesting that this monoterpene does not act on the fungal cell wall or by binding to ergosterol on the plasma membrane. Conclusion: therefore, these results contribute to the elucidation of the mechanism of action of thymol, suggesting other possible targets of drug-receptor interaction. However, further investigations of enzymatic and molecular character in in vitro models are necessary to fully elucidate the mode of action of this promising monoterpene.

Synergistic antibacterial activity of monoterpenes in combination with conventional antimicrobials against Gram-positive and Gram-negative bacteria / Atividade antibacteriana sinérgica de monoterpenos combinados com antimicrobianos convencionais frente a bactérias Gram-positivas e Gram-negativas

Introduction: bacterial infections are a public health problem. Besides, the emergence of strains resistant to antimicrobials has contributed to the search for new alternatives, such for the terpenes with antimicrobial potential. Objectives: the objective of this study was to determine the possible interaction of isolated monoterpenes (-)-Carveol, Geraniol, Citronellol, α-terpineol, R-(-) Carvone, (-)-Menthol, Linalool, D-Dihydrocarvone, and (-)-Terpine-4-ol with conventional antimicrobials (Chloramphenicol, Minocycline, Amoxicillin and Ciprofloxacin) when they are evaluated on Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa strains. Methodology: the minimum inhibitory concentrations of these test drugs were determined using the microdilution method. The Checkerboard method was used to assess the interactions, by determining the fractional inhibitory concentration index (FIC index). Results: aamong the monoterpenes, only Carveol, Citronellol, and Geraniol presented antimicrobial activity (MIC < 1024 µg/mL). They presented synergistic effects against Pseudomonas aeruginosa ATCC-9027 (FIC index ≤ 0.5) when in combination with Minocycline. Conclusion: this study contributes to the development of new approaches to control bacterial resistance and to the possibility of discovering new drugs.

Introdução: as infecções bacterianas são um problema de saúde pública. Além disso, o surgimento de cepas resistentes aos antimicrobianos tem contribuído para a busca de novas alternativas, como a pesquisa de terpenos com potencial antimicrobiano. Objetivos: o objetivo deste estudo foi determinar a possível interação de monoterpenos isolados (-) - Carveol, Geraniol, Citronelol, α-terpineol, R - (-) Carvona, (-)-Mentol, Linalol, D-Diidrocarvona e (-)-Terpina-4-ol com antimicrobianos convencionais (cloranfenicol, minociclina, amoxicilina e ciprofloxacina) quando avaliados em Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli e Pseudomonas aeruginosa. Metodologia: as concentrações inibitórias mínimas destas drogas foram determinadas usando o método de microdiluição. O método checkerboard foi utilizado para avaliar as interações, determinando o índice de concentração inibitória fracionária (índice FIC). Resultados: entre os monoterpenos, apenas Carveol, Citronelol e Geraniol apresentaram atividade antimicrobiana (CIM < 1024 µg/mL). Eles apresentaram efeitos sinérgicos contra Pseudomonas aeruginosa ATCC-9027 (índice FIC ≤ 0,5) quando em combinação com Minociclina. Conclusão: este estudo contribui para o desenvolvimento de novas abordagens para o controle da resistência bacteriana e para a possibilidade de descoberta de novas drogas.

Antifungal activity of geraniol and citronellol against food-relevant dematiaceous fungi Cladosporium spp / Atividade antifúngica de geraniol e citronelol frente a fungos dematiáceos de importância para os alimentos do gênero Cladosporium spp

Cladosporium spp. is a group of dematiaceous food-relevant fungi which are well dispersed in the environment causing food spoilage and poisoning. Considering the importance of fungal contamination, natural drugs to control their growth have become important. Thus, the aim of this study was to evaluate the inhibitory effects of two monoterpenoids, (geraniol and citronellol), against strains of Cladosporium carrioni, C. cladosporioides,and C. oxysporum. Methods: The Minimum Inhibitory Concentration (MIC) and Minimum Fungicide Concentration (MFC) of the drugs were determined by microdilution. The effects of test drugs on mycelial dry weight, conidia germination, and conidiogenesis of Cladosporium spp. were also investigated using a hemacytometer. Respective MIC and MFC values of citronellol varied from 256 to 512 μg/mL, and from 256 to 2048 μg/mL. The MIC and MFC of geraniol varied similarly to citronellol. Conidia germination, mycelial dry weight, and conidiogenesis of Cladosporium spp. were reduced by the test-drugs at 1/2MIC, MIC and 2xMIC (p<0.05). These measurable cell events are essential for fungal infection and development in foods. The action of citronellol and geraniol against Cladosporium spp. suggest that the drugs may serve as effective agents for controlling fungal contamination and growth in foods.

Cladosporium spp. é um grupo de fungos dematiáceos relevantes para os alimentos, que podem ser dispersos pelo ambiente e causar deterioração e intoxicação alimentar. Considerando a importância da contaminação fúngica, os produtos naturais usados para controlar seu crescimento são importantes. neste contexto, o objetivo deste estudo foi avaliar os efeitos inibitórios de dois monoterpenoides, geraniol e citronelol, contra cepas de Cladosporium carrioni, C. cladosporioides e C. oxysporum. A Concentração Inibitória Mínima (CIM) e Concentração Fungicida Mínima (CFM) das drogas foram determinadas por microdiluição. os efeitos das drogas-teste sobre a massa micelial seca, a germinação de conídios e a conidiogênese de Cladosporium spp. também foram investigados utilizando um hemocitômetro. os valores de CIM e CFM do citronelol variaram de 256 a 512 μg/mL e de 256 a 2048 μg/mL, respectivamente. CIM e CFM de geraniol variaram de forma semelhante. A germinação de conídios, massa micelial seca e conidiogênese de Cladosporium spp. foram inibidas pelas drogas-teste 1/2CIM, CIM e 2xCIM (p<0,05). Esses eventos celulares são essenciais para a infecção e desenvolvimento fúngico em alimentos. A ação de citronelol e geraniol contra Cladosporium spp. sugere que podem servir como agentes eficazes para controlar a contaminação fúngica e seu crescimento em alimentos.

Antifungal activity of geraniol and citronellol against food-relevantdematiaceous fungi cladosporium spp / Atividade antifúngica de geraniol e citronelol frente a fungos dematiáceos deimportância para os alimentos do gênero cladosporium spp

Cladosporium spp. is a group of dematiaceous food-relevant fungi which are well dispersed in the environment causing food spoilage and poisoning. Considering the importance of fungalcontamination, natural drugs to control their growth have become important. Thus, the aim of this study was to evaluate the inhibitory effects of two monoterpenoids, (geraniol and citronellol), against strains of Cladosporium carrioni, C. cladosporioides, and C. oxysporum. Methods: The Minimum Inhibitory Concentration (MIC) and Minimum Fungicide Concentration (MFC) of the drugs were determined by microdilution. The effects of test drugs on mycelial dry weight, conidia germination, and conidiogenesis of Cladosporium spp. were also investigated using a hemacytometer. Respective MIC and MFC values of citronellol varied from 256 to 512 µg/mL, and from 256 to 2048 µg/mL. The MIC and MFC of geraniol varied similarly to citronellol. Conidia germination, mycelial dry weight, and conidiogenesis of Cladosporium spp. were reduced by the test-drugs at 1/2MIC, MIC and 2xMIC (p<0.05). These measurable cell events are essential for fungal infection and development infoods. The action of citronellol and geraniol against Cladosporium spp. suggest that the drugs may serveas effective agents for controlling fungal contamination and growth in foods.

Cladosporium spp. é um grupo de fungos dematiáceos relevantes para os alimentos, que podem ser dispersos pelo ambiente e causar deterioração e intoxicação alimentar. Considerando a importância da contaminação fúngica, os produtos naturais usados para controlar seu crescimentosão importantes. Neste contexto, o objetivo deste estudo foi avaliar os efeitos inibitórios de dois monoterpenoides, geraniol e citronelol, contra cepas de Cladosporium carrioni, C. cladosporioides eC. oxysporum. A Concentração Inibitória Mínima (CIM) e Concentração Fungicida Mínima (CFM) das drogas foram determinadas por microdiluição. Os efeitos das drogas-teste sobre a massa micelialseca, a germinação de conídios e a conidiogênese de Cladosporium spp. também foram investigados utilizando um hemocitômetro. Os valores de CIM e CFM do citronelol variaram de 256 a 512 μg/mLe de 256 a 2048 μg/mL, respectivamente. CIM e CFM de geraniol variaram de forma semelhante. A germinação de conídios, massa micelial seca e conidiogênese de Cladosporium spp. foram inibidaspelas drogas-teste 1/2CIM, CIM e 2xCIM (p<0,05). Esses eventos celulares são essenciais para a infecção e desenvolvimento fúngico em alimentos. A ação de citronelol e geraniol contra Cladosporium spp. sugere que podem servir como agentes eficazes para controlar a contaminação fúngica e o seucrescimento em alimentos.

Phytoconstituents from Sidastrum micranthum (A. St.-Hil.) Fryxell (Malvaceae) and antimicrobial activity of pheophytin a

abstract Sidastrum micranthum (A. St.-Hil.) Fryxell, a member of the Malvaceae family, is called malva preta in Brazil. As this species is commonly used to treat bronchitis, cough, and asthma, better knowledge of its chemical compounds is important. The phytochemical study of its hexane extract, using chromatographic techniques, led to isolation of six compounds: the triterpene isoarborinol, a mixture of sitosterol and stigmasterol, sitosterol-3-O-β-D-glucopyranoside, pheophytin a, and 132-hydroxy-(132-S)-pheophytin a. Structural identification of these compounds was carried out using spectroscopic methods such as IR and 1D and 2D NMR (HOMOCOSY, HMQC, HMBC, and NOESY). Compounds isolated from S. micranthum were screened for their in vitro antifungal and antibacterial activity against twenty fungal and bacterial standard strains. Pheophytin a exhibited antimicrobial action against all microorganisms tested.

resumo Sidastrum micranthum (A. St.-Hil.) Fryxell, pertencente à família Malvaceae, é conhecida no Brasil como "malva preta". A espécie é popularmente usada contra bronquite, tosse e asma, mostrando a relevância de conhecer melhor sua composição química. O estudo fitoquímico do extrato hexânico da espécie, utilizando técnicas cromatográficas, conduziu ao isolamento de seis compostos: o triterpeno isoarborinol, mistura de sitosterol e estigmasterol, sitosterol-3-O-β-D-glicopiranosídeo, feofitina a e de 132-hidroxi-(132-S)-feofitina a. A identificação estrutural destes compostos foi realizada com base em métodos espectroscópicos, tais como IV, RMN 1D e 2D (HOMOCOSY, HMQC, HMBC e NOESY). As substâncias isoladas de Sidastrum micranthum foram avaliadas quanto às suas atividades antimicrobianas in vitro, contra vinte cepas fúngicas e bacterianas. A feofitina a mostrou ação antimicrobiana contra todos os microrganismos testados.

Identificação da microbiota fúngica anemófila em uma indústria de polpas de frutas e susceptibilidade antifúngica a terpenos / Identification of the airborne fungal microbiota in a fruit pulp industry and antifungal susceptibility to terpenes

Os fungos anemófilos são importantes agentes contaminantes e deteriorantes de alimentos, especialmente frutas e seus produtos. Neste estudo foram identificados os principais gêneros fúngicos presentes na microbiota anemófila de uma indústria de polpas de frutas, localizada no interior da Paraíba, e foi investigada a ação antifúngica de terpenos como possível alternativa de controle do crescimento fúngico. Os fungos foram coletados pela exposição de placas de Petri contendo meio Agar Sabouraud dextrose com cloranfenicol (50 μg/mL). Após a incubação a 28 °C durante sete dias, foram realizadas a contagem das unidades formadoras de colônias e sua descrição. Os fungos foram identificados pela análise morfológica das colônias isoladas. O principal gênero isolado em toda indústria foi o dematiáceo Cladosporium spp. Os ensaios de sensibilidade foram efetuados aplicando-se a técnica de difusão em meio sólido com discos contendo os terpenos: carvacrol, citronelal, citral, linalol, timol, terpinoleno, p-cimeno e β-cariofileno. A efetividade de alguns destes terpenos frente a cepas do Cladosporium spp foi demonstrada, com destaque para o citral e carvacrol. A indústria de polpas de frutas apresenta ar de ambiente vulnerável, especialmente contaminação por Cladosporium spp. Pretende-se impulsionar novos estudos com produtos naturais na perspectiva de diminuir a contaminação fúngica em alimentos.

Airborne fungi are important food contaminants and spoiling agents, especially in fruits and their derivatives. This study aimed at identifying the main fungi in the airborne microbiota in a fruit pulp industry, located in Paraíba State, and to investigate the antifungal action of terpenes as an alternative for controlling fungal growth. The Petri plates containing Sabouraud dextrose agar with chloramphenicol (50 μg/mL) were exposed for collecting the fungi. The plates were incubated at 28 °C for seven days; then the colony forming unitscounting, and description were performed. The identification of fungi was performed by the morphological analysis of isolated colonies. The main group of fungi isolated throughout the industry was Cladosporium spp. Antifungal tests were performed by diffusion technique in solid medium with discs containing terpenes: carvacrol, citronellal, citral, linalool, thymol, terpinolene, p-cymene and β-caryophyllene. The effectiveness of some of these terpenes against Cladosporium spp. strains was shown, especially citral and carvacrol. Based on these results, the fruit pulp industry shows vulnerable ambient air, notably with high contamination by Cladosporium spp. Thus, it is aimed at promoting further studies with natural drugs in order to reduce the fungal contamination in food.

Investigation of Melissa officinalis L. Essential Oil for Antifungal Activity against Cladosporium carrionii.

Cladosporium carrionii is considered the most important pathogenic species of genus because of the numerous cases of disease which causes in the world. Due to its antifungal resistance, these fungal infections are difficult to treat. Given the broad biological activity displayed by natural products, essential oils obtained from plants are often investigated to determine their antimicrobial activity. Aims: Therefore, we identified components of Melissa officinalis L. essential oil, investigating in vitro antifungal activity against strains of C. carrionii. Methodology: Identification of the chemical composition of the oil was performed by gas chromatography coupled to a mass spectrometer (GC-MS). The antifungal activity of M. officinalis L. essential oil was investigated against 08 strains of C. carrionii determining minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), effects on mycelial growth, and conidial germination. Results: The GC-MS results revealed 4 major components; geranial (52%), citral (38.90%), trans- β-caryophyllene (1.22%), and germacrene D (0.84%). M. officinalis L. essential oil inhibited the growth of all (100%) of the strains of C. carrionii tested. The MIC and MFC were established at 256 μg/ml. Inhibition of radial mycelial growth began at 128 μg/ml (MIC/2), and at both 2 x MIC and 4 x MIC the inhibition was complete. We also observed significant conidial germination inhibition at all concentrations when compared to the control (P<0.05). The inhibition increased with concentration so that at 2 x MIC complete (100%) conidia germination inhibition was observed. Conclusion: Finally, our study results point to M. officinalis L. essential oil as a potential antifungal agent against C. carrionii.

Treatment of pityriasis versicolor with topical application of essential oil of Cymbopogon citratus (DC) Stapf - therapeutic pilot study / Tratamento de pitiríase versicolor com aplicação tópica do óleo essencial de Cymbopogon citratus (DC) Stapf - estudo terapêutico piloto

BACKGROUND: Pityriasis versicolor is a fungal infection caused by Malassezia spp. that has frequent relapses. OBJECTIVES: The main objective of this research was to perform phase I and II clinical studies, using formulations containing essential oil of Cymbopogon citratus in patients with pityriasis versicolor. METHODS: Phase I study included twenty volunteers to ascertain the safety of the formulations. In phase II, 47 volunteers randomly received essential oil formulations at 1.25 μL/mL concentration, for forty days. The shampoo should be applied three times a week and the cream twice a day. A control group in phase II, consisting of 29 volunteers, received the same formulations but with 2% ketoconazole as the active ingredient. RESULTS: No significant adverse events were observed in volunteers during Phase I. In Phase II, 30 (63.83%) volunteers using essential oil and 18 (62.07%) using ketoconazole remained until the end of the study. We observed a predominance of lesions in disseminated form, with M. sympodialis detected as the predominant agent identified in cultures. After 40 days of treatment, the rate of mycological cure was 60% (p <0.05) for the group treated with essential oil of C. citratus and over 80% (p <0.05) for the group treated with ketoconazole formulations. CONCLUSIONS: Notwithstanding the safety and antifungal effects observed in this study after application of formulations containing the essential oil of C. citratus, further studies with larger populations should be performed to confirm the actual potential of these formulations in the treatment of patients with Pityriasis versicolor. .

FUNDAMENTOS: Pitiríase versicolor é uma micose causada pela Malassezia spp., e que apresenta frequentes recidivas. OBJETIVOS: Este trabalho objetivou realizar estudos clínicos de fase I e II, para essa patologia, com óleo essencial de Cymbopogon citratus. MÉTODOS: Na fase I, participaram vinte voluntários para averiguar a segurança das formulações. Na fase II, 47 voluntários receberam as formulações do óleo essencial a 1,25 μL/mL, as quais deveriam ser utilizadas por quarenta dias, sendo o xampu três vezes por semana e o creme duas vezes ao dia. Um grupo controle na fase II, constituído por 29 voluntários recebeu as mesmas formulações, com cetoconazol a 2%. RESULTADOS: Verificada a segurança das formulações com a finalização da fase I, onde nenhuma reação adversa significativa foi observada nos indivíduos sadios, conduziu-se a fase II. Nesta segunda fase, 30 (63,83%) voluntários utilizando óleo essencial e 18 (62,07%) cetoconazol permaneceram até o final do estudo. Observaram-se nos pacientes com pitiríase versicolor predomínio de lesões na forma disseminada e M. sympodialis foi o agente predominante identificado em cultura. Após 40 dias de tratamento, obteve-se um percentual de cura micológica de 60% (p < 0,05) para o grupo tratado com óleo essencial de C. citratus e superior a 80% (p < 0,05) para o grupo tratado com cetoconazol. CONCLUSÕES: Apesar da segurança e efeito antifúngico observados após aplicação das formulações contendo óleo essencial de C. citratus, outros estudos com maior número de portadores de pitiríase versicolor precisam ser realizados para confirmar o real potencial destas f...

Essential oil from Cymbopogon citratus (DC) Stapf: a promising natural product against Malassezia spp

This study evaluated the sensitivity of Malassezia spp. strains, the etiologic agent of pityriasis versicolor, to essential oil from Cymbopogon citratus. The chemical composition of the essential oil was analysed by GC-MS, and the major constituents were: geraniol (52.80%), neral (36.65%) and myrcene (3.73%). The minimum inhibitory concentration (MIC) of C. citratus essential oil on to 22 strains of Malassezia spp. were determined by agar dilution technique in the presence and absence of ergosterol (50-250 ìg/mL) and sorbitol (0.8 M). Increased MIC values in the presence of ergosterol indicate an effect on fungal membrane, and the higher MIC values in the presence of sorbitol indicate a mechanism of action on thecell wall. The MIC ranged from 0.31 to 1.25 ìL/mL and it increased fourfold in the presence of ergosterol, regardless of concentration tested; and this fact was most likely related to the occurrence of the oil and exogenous ergosterol complexes. No change in MIC values in the presence of sorbitol was found. The sedata infer that C. citratus essential oil causes an effect on Malassezia spp. plasma membrane synthesis by binding to ergosterol. This study contributes to the development of new antifungal drugs, especially against Malassezia spp.

Actividad antifúngica del aceite esencial de Eugenia caryophyllata sobre cepas de Candida tropicalis de aislados clínicos / Antifungal activity of the essential oil of Eugenia caryophyllata on Candida tropicalis strains from clinical isolates

Candidiasis is an opportunistic fungal infection caused by Candida yeasts. In Brazil, C. tropicalis is the second most frequently isolated microorganism after C. albicans. The arising of strains resistant to conventional antifungal agents has increased the search for new alternatives from natural products, especially essential oils. This research investigated essential oil activity against strains of C. tropicalis by disk diffusion method. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were also determinate. In the disk diffusion, the essential oils of Cinnamomum zeylanicum, Eugenia caryophyllata and Origanum vulgare had the highest inhibition zones values. MIC and MFC values of E. caryophyllata essential oil were 512 and 1024 ug/mL, respectively. MIC and MFC amphotericin B values were identical (2 ug/mL). Therefore, it was concluded that E. caryophyllata essential oil has strong antifungal activity and may be subject to further studies.

La candidiasis es una infección fúngica oportunista causada por levaduras del género Candida. En Brasil, la especie C. tropicalis esta siendo aislada frecuentemente, es el segundo microorganismo más aislado después de C. albicans. La aparición de cepas resistentes a los antifúngicos convencionales ha aumentado la búsqueda de nuevas alternativas provenientes de productos naturales, especialmente los aceites esenciales. En este estudio se investigó la actividad de los aceites esenciales contra las cepas de C. tropicalis, utilizando el método de difusión en disco, la concentración inhibitoria mínima (CIM) y la concentración fungicida mínima (CFM). En el método de difusión en disco, con los aceites esenciales de Cinnamomum zeylanicum, Eugenia caryophyllata y Origanum vulgare se obtuvieron mayores valores de inhibición. La CIM y CFM del aceite esencial de Eugenia caryophyllata fueron 512 y 1024 ug/mL, mientras que los de la anfotericina B fueron idénticos, 2 ug/mL. Por lo tanto, se puede concluir que el aceite esencial de E. caryophyllata tiene potente actividad antifúngica y puede ser objeto de nuevos estudios sobre esta actividad.

Antifungal activity of Cymbopogon winterianus jowitt ex bor against Candida albicans

Candida albicans is an opportunistic yeast and a member of the normal human flora that commonly causes infections in patients with any type of deficiency of the immune system. The essential oils have been tested for antimycotic activity and pose much potential as antifungal agents. This work investigated the activity of the essential oil of Cymbopogon winterianus against C. albicans by MIC, MFC and time-kill methods. The essential oil (EO) was obtained by hydrodistillation using a Clevenger-type apparatus. It was tested fifteen strains of C. albicans. The MIC was determined by the microdilution method and the MFC was determined when an aliquot of the broth microdilution was cultivated in SDA medium. The phytochemical analysis of EO showed presence of citronellal (23,59 percent), geraniol (18,81 percent) and citronellol (11,74 percent). The EO showed antifungal activity, and the concentrations 625 µg/mL and 1250 µg/mL inhibited the growth of all strains tested and it was fungicidal, respectively. The antimicrobial activity of various concentrations of EO was analyzed over time, it was found concentration-dependent antifungal activity, whose behavior was similar to amphotericin B and nystatin.

Growth inhibition and morphological alterations of Trichophyton rubrum induced by essential oil from Cymbopogon winterianus Jowitt ex Bor

Trichophyton rubrum is one of the most common fungi causer of dermatophytosis, mycosis that affect humans and animals around the world. Researches aiming new products with antifungal activity become necessary to overcome difficulties on treatment of these infections. Accordingly, this study aimed to investigate the antifungal activity of essential oil from Cymbopogon winterianus against the dermatophyte T. rubrum. The antifungal screening was performed by solid medium diffusion method with 16 T. rubrum strains, minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were determined using the microdilution method. The effects on mycelial dry weight and morphology were also observed. Screening showed essential oil in natura inhibited all the tested strains, with inhibition zones between 24-28 mm diameter. MIC50 and MIC90 values of the essential oil were 312 µg/mL for nearly all the essayed strains (93.75 percent) while the MFC50 and MFC90 values were about eight times higher than MIC for all tested strains. All tested essential oil concentrations managed to inhibit strongly the mycelium development. Main morphological changes on the fungal strains observed under light microscopy, which were provided by the essential oil include loss of conidiation, alterations concerning form and pigmentation of hyphae. In the oil presence, colonies showed folds, cream color and slightly darker than the control, pigment production was absent on the reverse and with evident folds. It is concluded that C. winterianus essential oil showed activity against T. rubrum. Therefore, it could be known as potential antifungal compound especially for protection against dermatophytosis.

Effects of Cymbopogon winterianus Jowitt ex Bor essential oil on the growth and morphogenesis of Trichophyton mentagrophytes / Efeitos do óleo essencial de Cymbopogon winterianus Jowitt ex Bor no crescimento e na morfogênese de Trichophyton mentagrophytes

Trichophyton mentagrophytes is a fungus causative agent of dermatophytosis, affecting humans worldwide. This has driven the search for products for the treatment of these infections. Accordingly, the aim of this study was to investigate the antifungal activity of the Cymbopogon winterianus essential oil against T. mentagrophytes. The antifungal tests consisted of antifungal screening, determination of MIC and MFC, analysis of the essential oil's effects on mycelial growth, germination of fungal spores, fungal viability, morphogenesis, cell wall (test with sorbitol) and cell membrane (cell leakage test) of T. mentagrophytes. Upon screening, the oil inhibited all strains, with zones of growth inhibition of 24-28 mm in diameter. The MIC was 312 μg/mL and CFM was 2500 μg/mL for almost all the strains tested. There were morphological changes in the conidia group, form and pigmentation of hyphae. The antifungal action of the product does not involve the cell wall and its action may involve the fungal plasma membrane. It is concluded that C. winterianus essential oil constitutes a potential antifungal product, especially for the treatment of dermatophytosis.

Trichophyton mentagrophytes é um fungo causador de dermatofitoses, afetando humanos em todo o mundo. Isto direciona a busca de produtos para o tratamento destas infecções. Assim, este estudo teve por objetivo investigar a atividade antifúngica do óleo essencial de Cymbopogon winterianus contra T. mentagrophytes. Os ensaios antifúngicos foram constituídos do screening antifúngico, da determinação CIM e CFM, da análise dos efeitos do óleo essencial no crescimento micelial, na germinação dos esporos, na viabilidade fúngica, na morfogênese, na parede celular (ensaio com sorbitol) e na membrana celular (ensaio de lise celular) de T. mentagrophytes. No screening, o óleo inibiu todas as cepas, com zonas de inibição de crescimento de 24-28 mm de diâmetro. A CIM foi de 312 μg/mL e a CFM foi de 2500 μg/mL para quase todas as cepas testadas. O óleo essencial inibiu o desenvolvimento micelial, a germinação dos esporos e a viabilidade fúngica. Houve alterações morfológicas no agrupamento dos conídios, na forma e pigmentação das hifas. A ação antifúngica do produto não envolve a parede celular e parece estar envolvida com a membrana celular fúngica. Pode-se concluir que o óleo essencial de C. winterianus se apresenta como um potencial produto antifúngico, especialmente para o tratamento das dermatofitoses.

Efficacy of Origanum essential oils for inhibition of potentially pathogenic fungi / Eficácia de Origanum óleos essenciais para a inibição de fungos potencialmente patogênicos

This study aimed to assess the efficacy of O. vulgare L. and O. majorana L. essential oil in inhibiting the growth and survival of potentially pathogenic fungal strains and also sought to evaluate the possible mechanisms involved in the establishment of the antifungal property of the tested essential oils through assays of osmotic stability and morphogenesis. Test strains included in this study were Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 and Cladosporium herbarium ATCC 26362. O. vulgare essential oil presented a MIC value of 80 µL/mL, while for O. majorana this was 160 µL/mL. C. krusei LM-09 was the only strain resistant to all assayed concentrations of both essential oils. O. vulgare and O. majorana essential oil at their MIC values provided a cidal effect against C. albicans ATCC 7645 after 4 h of exposure. O. vulgare essential oil at 80 µL/mL exhibited 100 percent inhibition of the radial mycelia growth of T. rubrum ATCC 28184 and M. canis LM-36 for 14 days. Assayed fungus strain protected by sorbitol (osmo-protectant agent) grew in media containing higher concentrations of O. vulgare and O. majorana essential oil in comparison to media without sorbitol, suggesting some specificity of these essential oils for targeting cell wall in the fungi cell. Main morphological changes observed under light microscopy provided by the essential oil of O. vulgare in A. flavus LM-02 were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. These results suggest that essential oils from Origanum could be regarded as a potential antifungal compound for controlling the growth of pathogen fungi and the occurrence of mycoses.

O objetivo deste estudo foi observar a eficácia do óleo essencial de O. vulgare L. e O. majorana L. na inibição do crescimento e sobrevivência de cepas de fungos potencialmente patogênicas, bem como avaliar os possíveis mecanismos envolvidos no estabelecimento da propriedade antifúngica dos óleos essenciais testados através do ensaio de estabilidade osmótica e morfogênese. As cepas fúngicas utilizadas neste estudo foram Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 e Cladosporium herbarium ATCC 26362. O óleo essencial de O. vulgare apresentou valor de CIM de 80 µL/mL, enquanto o óleo essencial de O. majorana apresentou valor de CIM de 160 µL/mL. C. krusei LM-09 apresentou-se como a única cepa resistente a todas as concentrações ensaiadas de ambos os óleos essenciais. Os óleos essenciais testados quando ensaiadas em seu valor de CIM causaram um efeito fungicida contra C. albicans ATCC 7645 após 4 h de exposição. O óleo essencial de O. vulgare na concentração de 80 µL/mL exibiu uma total inibição do crescimento micelial radial de T. rubrum ATCC 28184 e M. canis LM-36 ao longo de 14 dias. As cepas fúngicas ensaiadas quando tratadas com sorbitol (agente osmo-protetor) foram capazes de crescer em meio adicionado de mais altas concentrações dos óleos essenciais quando comparados ao meio não adicionado de sorbitol, sugerindo especificidade destes produtos a parede celular como alvo na célula fúngica. As principais alterações causadas pelo óleo essencial de O. vulgare sobre a morfologia de A. flavus LM-02 foram diminuída conidiação, perda de citoplasma, perda de pigmentação e ruptura da estrutura celular indicando degeneração da parede celular fúngica. Estes resultados sugerem que óleos essenciais de espécies de Origanum poderiam ser considerados como potenciais antifúngicos para ...

Microbiota fúngica do solo e ar atmosférico na região da Borborema, estado da Paraíba, Brasil / Fungal microbiota from the soil and atmospheric air in the region of Borborema, Paraíba state, Brazil

O solo e o ar atmosférico constituem o grande habitat fúngico, sendo considerados as principais fontes de infecções dos mesmos. Dessa maneira, o presente trabalho teve como objetivos isolar, quantificar e identificar espécies do solo e do ar atmosférico na região da Borborema-Paraíba. Foram coletadas quarenta e quatro amostras em diferentes pontos da região. No solo, foram feitas suspensões das amostras e inoculadas 0,1mL do sobrenadante na superfície de meios de cultura. Para amostras do ar, foi utilizada atécnica de exposição de placas de Petri com meio de cultura. Os fungos predominantes no ar atmosférico foram: Penicillium sp(21,07), fungos não esporulados (FNE) (17,74) e Aspergillus niger (10,54). E no solo: Aspergillus flavus (21,92), Acremonium sp (21,50) e FNE (14,85.). Neste estudo, foi observado que os fungos isolados podem causar infecções em variáveis níveis de complexidade, ocupando lugar de destaque entre as doenças tropicais.

Antimicrobial activity of the essential oil of Bowdichia virgilioides Kunt. / Atividade antimicrobiana do óleo essencial de Bowdichia virgilioides Kunt.

The essential oil of Bowdichia virgilioides Kunt. (Fabaceae) leaves was tested for their antimicrobial activity against eighteen pathogenic microorganisms using standard gel diffusion method. It showed activity against Candida albicans, Candida guilliermondii, Candida stellatoidea, Micrococcus luteus and Trichophyton rubrum.

O óleo essencial das folhas de Bowdichia virgilioides Kunt. (Fabaceae) foi testado para a verificação da sua atividade antimicrobiana contra dezoito microorganismos patogênicos, usando o método de difusão em meio sólido. Foi observada atividade contra Candida albicans, Candida guilliermondii, Candida stellatoidea, Micrococcus luteus e Trichophyton rubrum.

Antimicrobial activity of the essential oil of Sida cordifolia L. / Atividade antimicrobiana do óleo essencial de Sida cordifolia L.

The analysis of the antimicrobial activity of the essential oil of Sida cordifolia was evaluated with four different strains of bacteria and nine fungi. The essential oil was tested "in natura" (100 percent) and diluted from 32 until 2 percent. The microorganisms, bacteria and fungi, were spread in agar Muller-Hinton and Sabouraud dextrose, respectively. S. cordifolia showed inhibitory activity against the microorganisms tested with efficacy of 80 percent. When tested against Staphylococcus aureus, Staphyllococus epidermidis, Candida guilliermondii and Trichosporon inkin the essential oil showed the best performance.

A análise da atividade antimicrobiana do óleo essencial de Sida cordifolia foi avaliada com quatro diferentes cepas de bactérias e nove de fungos. O óleo essencial foi testado "in natura" 100 por cento e diluído de 32 até 2 por cento. Os microrganismos, bactérias e fungos, foram semeados em ágar Muller-Hinton e Sabouraud dextrose, respectivamente. S. cordifolia mostrou atividade inibitória contra os microrganismos testados com eficácia de 80 por cento. Quando testado contra Staphyllococus aureus, Staphyllococus epidermidis, Candida guilliermondii e Trichosporon inkin o óleo essencial mostrou um melhor desempenho.

Antimicrobial effectiveness of maleimides on fungal strains isolated from onychomycosis

This study aimed to analyze the effectiveness of maleimides as inhibitors on the growth of fungal strains isolated from onychomycosis by the solid medium diffusion procedure. The results showed a promising antifungical activity of the assayed maleimides with formation of fungal growth inhibition halos oscillating between diameter 10 and 23mm. MIC was 100æg/mL for 3,4-dichloro-N-phenyl-methyl-maleimide and 3,4-dichloro-N-phenyl-propil-maleimide and 200æg/mL for 3,4-dichloro-N-phenyl-maleimide, 3,4-dichloro-N-phenyl-ethyl-maleimide and 3,4-dichloro-N-phenyl-buthyl-maleimide.

Este estudo objetivou analisar a efetividade de maleimidas como inibidores do crescimento de cepas fúngicas isoladas de onicomicoses através da técnica de difusão em meio sólido. Os resultados mostraram destacável atividade antifúngica das maleimidas ensaiadas com a formação de halos de inibição do crescimento fúngico com diâmetros oscilando entre 10 e 23mm. A CIM encontrada foi 100æg/mL para 3,4-dicloro-N-fenil-metil-maleimida e 3,4-dicloro-N-fenil-propil-maleimida e 200æg/mL para 3,4-dicloro-N-fenil-maleimida, 3,4-dicloro-N-fenil-etil-maleimida e 3,4-dicloro-N-fenil-butil-maleimida.