Phytochemical composition, antifungal activity, in vitro and in vivo toxicity of Syzygium cumini (L) Skeels leaves extract / Composición fitoquímica, actividad antifúngica, toxicidad in vitro e in vivo del extracto de hojas de Syzygium cumini (L) Skeels

This study determined phytochemical composition, antifungal activity and toxicity in vitro and in vivo of Syzygium cumini leaves extract (Sc). Thus, was characterized by gas chromatography coupled to mass spectrometry and submitted to determination of Minimum Inhibitory (MIC) and Fungicidal concentrations (MFC) on reference and clinical strains of Candida spp. and by growth kinetics assays. Toxicity was verified using in vitro assays of hemolysis, osmotic fragility, oxidant and antioxidant activity in human erythrocytes and by in vivo acute systemic toxicity in Galleria mellonella larvae. Fourteen different compounds were identified in Sc, which showed antifungal activity (MIC between 31.25-125µg/mL) with fungistatic effect on Candida. At antifungal concentrations, it demonstrated low cytotoxicity, antioxidant activity and neglible in vivotoxicity. Thus, Sc demonstrated a promising antifungal potential, with low toxicity, indicating that this extract can be a safe and effective alternative antifungal agent.

Este estudio determinó la composición fitoquímica, la actividad antifúngica y la toxicidad in vitro e in vivo del extracto de hojas de Syzygium cumini (Sc). Así, se caracterizó mediante cromatografía de gases acoplada a espectrometría de masas y se sometió a determinación de Concentraciones Mínimas Inhibitorias (CMI) y Fungicidas (MFC) sobre cepas de referencia y clínicas de Candida spp. y mediante ensayos de cinética de crecimiento. La toxicidad se verificó mediante ensayos in vitro de hemólisis, fragilidad osmótica, actividad oxidante y antioxidante en eritrocitos humanos y por toxicidad sistémica aguda in vivo en larvas de Galleria mellonella. Se identificaron catorce compuestos diferentes en Sc, que mostraron actividad antifúngica (CMI entre 31.25-125 µg/mL) con efecto fungistático sobre Candida. En concentraciones antifúngicas, demostró baja citotoxicidad, actividad antioxidante y toxicidad in vivo insignificante. Por lo tanto, Sc demostró un potencial antifúngico prometedor, con baja toxicidad, lo que indica que este extracto puede ser un agente antifúngico alternativo seguro y eficaz.

Recent progress on anti-Candida natural products / 中国天然药物

Candida is an intractable life-threatening pathogen. Candida infection is extremely difficult to eradicate, and thus is the major cause of morbidity and mortality in immunocompromised individuals. Morevover, the rapid spread of drug-resistant fungi has led to significant decreases in the therapeutic effects of clinical drugs. New anti-Candida agents are urgently needed to solve the complicated medical problem. Natural products with intricate structures have attracted great attention of researchers who make every endeavor to discover leading compounds for antifungal agents. Their novel mechanisms and diverse modes of action expand the variety of fungistatic agents and reduce the emergence of drug resistance. In recent decades, considerable effort has been devoted to finding unique antifungal agents from nature and revealing their unusual mechanisms, which results in important progress on the development of new antifungals, such as the novel cell wall inhibitors YW3548 and SCY-078 which are being tested in clinical trials. This review will present a brief summary on the landscape of anti-Candida natural products within the last decade. We will also discuss in-depth the research progress on diverse natural fungistatic agents along with their novel mechanisms.

Diphenyl Diselenide and Clotrimazole Co-loaded into Eudragit® RS 100 Nanocapsules Formulation Has Superior Antioxidant Potential and Promising Anti-candida Activity

Abstract In the current study, nanocapsules (NC) formulations containing a co-load of clotrimazole (C), a highly prescribed antifungal drug, and diphenyl diselenide [(PhSe)2], an organoselenium compound with a promising scope of pharmacological actions, were prepared. Formulations were characterized as well as the potential toxicity, antioxidant action, and antifungal effect were assessed using in vitro techniques. The NCs were prepared employing Eudragit® RS 100 as polymeric wall and medium chain triglycerides or virgin coconut oil (CO) as core. All NC suspensions had pH around acid range, compound content close to theoretical value (1 mg/mL/drug), average diameter in nanometric range, positive values of zeta potential as well as high encapsulation efficacy and mucoadhesive property. Physicochemical stability was performed over a 30-day period and showed no modification in the aforementioned parameters to all samples. Preliminary screening of toxicological potential performed by the hen's egg test chorioallantoic membrane technique classified the formulations as non-irritant. The DPPH radical assay revealed that nanoencapsulated compounds had superior antioxidant action in comparison to their free forms (concentration range tested 1.0-25.0 µg/mL). Importantly, the formulation composed of CO and containing C and (PhSe)2 showed the highest antioxidant potential and was selected for further investigation regarding antifungal effect against some Candida spp strains. Results of in vitro antifungal assay demonstrated that the C and (PhSe)2 co-encapsulation had a minimum inhibitory concentration (MIC) values around 60. Thus, our study supplies additional data about advantages achieved by encapsulating active compounds.

Effect of Cinnamomum verum leaf essential oil on virulence factors of Candida species and determination of the in-vivo toxicity with Galleria mellonella model

BACKGROUND Essential oils (EO) extracted from Cinnamomum verum has been used as an antimicrobial agents for centuries. The effects of C. verum leaf oil against virulence of microorganisms is not well studied yet. OBJECTIVES This study evaluates the effect of C. verum leaf oil against three virulence factors of Candida albicans, C. tropicalis and C. dubliniensis and its in-vivo toxicity. METHODS Chemical composition of EO was determined using gas chromatography-mass spectrometry (GC-MS). Minimum inhibitory concentration (MIC) was determined using clinical and laboratory standards institute (CLSI) M27-A3 broth microdilution. Effect of EO on initial adhesion was quantified using XTT assay after allowing Candida cells to adhere to the polystyrene surface for 2 h. Biofilm formation of Candida in the presence of EO was quantified using XTT viability assay. Efficacy on reduction of germ tube formation was evaluated using standard protocol. Visualisation of biofilm formation and progression under the EO treatment were done using scanning electron microscope (SEM) and Time lapses microscope respectively. In-vivo toxicity of EO was determined using Galleria mellonella larvae. Chlorhexidine digluconate: positive control. RESULTS Eugenol was the main compound of EO. MIC was 1.0 mg/mL. 50% reduction in initial adhesion was achieved by C. albicans, C. tropicalis and C. dubliniensis with 1.0, > 2.0 and 0.34 mg/mL respectively. 0.5 and 1.0 mg/mL significantly inhibit the germ tube formation. MBIC50 for forming biofilms were ≤ 0.35 mg/mL. 1.0 mg/mL prevent biofilm progression of Candida. SEM images exhibited cell wall damages, cellular shrinkages and decreased hyphal formation. No lethal effect was noted with in-vivo experiment model at any concentration tested. CONCLUSION C. verum leaf oil acts against virulence factors of Candida and does not show any toxicity.

Chemical composition of essential oils from the apiaceae family, cytotoxicity, and their antifungal activity in vitro against candida species from oral cavity / Composição química de óleos essenciais da família apiaceae, citotoxicidade e sua atividade antifúngica in vitro contra espécies de candida da cavidade oral

Abstract The aims of this research were: evaluate the chemical composition and the cytotoxicity of the Cuminum cyminum (cumin), Anethum graveolens (dill), Pimpinella anisum (anise) and Foeniculum vulgare (fennel) essential oils, as well as their antifungal activity in vitro against ten Candida spp. isolates. The chemical composition of the oils was analyzed by means of gas chromatography coupled with mass spectrometry (GC/MS). The cytotoxicity assays were performed, using the cell proliferation reagent WST-1 in L929 mouse fibroblasts (20x103 well-1). The determinate the Minimum Inhibitory Concentration (MIC), was performed through the Broth Microdilution technique (CLSI). The chemical main components were the cuminaldehyde (32.66%) for cumin, carvone (34.89%) for the dill, trans-anethole (94.01%) for the anise and anethole (79.62%) for the fennel. Anise and fennel did not were cytotoxic in all the tested concentrations, however the cumin oil was cytotoxic in the concentration of 20 mg.mL-1 and the dill in the concentrations of 20 and 8 mg.mL-1. All yeasts were susceptible against the evaluated essential oils. Cumin presented the lowest MIC against yeasts. We concluded that all the essential oils presented inhibitory action against Candida spp., and C . cyminum, P. anisum and F. vulgare were not cytotoxic in the same minimum inhibitory concentrations for the fungi.

Resumo Os objetivos desta pesquisa foram: avaliar a composição química e a citotoxicidade dos óleos essenciais de Cuminum cyminum (cominho), Anethum graveolens (endro), Pimpinella anisum (erva-doce) e Foeniculum vulgare (funcho), bem como sua atividade antifúngica in vitro contra dez isolados de Candida spp.. A composição química dos óleos foi analisada por meio de cromatografia gasosa acoplada à espectrometria de massa (GC / MS). Os ensaios de citotoxicidade foram realizados, utilizando o reagente de proliferação celular WST-1 em fibroblastos de ratinho L929 (20x103 poço-1). A determinação da Concentração Inibitória Mínima (MIC) foi realizada através da técnica de microdiluição em caldo (CLSI). Os principais componentes químicos foram o cuminaldeído (32.66%) para cominho, carvona (34.89%) para o endro, trans-anetol (94.01%) para erva-doce e anetol (79.62%) para a funcho. O endro e a erva-doce não foram citotóxicos em todas as concentrações testadas, no entanto, o óleo de cominho foi citotóxico na concentração de 20 mg.mL-1 e o endro nas concentrações de 20 e 8 mg.mL-1. Todas as leveduras foram suscetíveis aos óleos essenciais avaliados. O cominho apresentou a menor CIM contra as leveduras. Concluímos que todos os óleos essenciais apresentaram ação inibidora contra Candida spp., e C. cyminum, P. anisum e F. vulgare não foram citotóxicos nas mesmas concentrações inibitórias mínimas para os fungos.

Anadenanthera Colubrina vell Brenan: anti-Candida and antibiofilm activities, toxicity and therapeutical action

Abstract: We evaluated the antifungal and antibiofilm potential of the hydroalcoholic extract of bark from Anadenanthera colubrina (vell.) Brenan, known as Angico, against Candida spp. Antifungal activity was evaluated using the microdilution technique through the Minimum Inhibitory and Fungicide Concentrations (MIC and MFC). The antibiofilm potential was tested in mature biofilms formed by Candida species and analyzed through the counting of CFU/mL and scanning electron micrograph (SEM). In vivo toxicity and therapeutic action was evaluated in the Galleria mellonella model. The treatment with the extract, in low doses, was able to reduce the growth of planktonic cells of Candida species. MIC values range between 19.5 and 39 µg/mL and MFC values range between 79 and 625 µg/mL. In addition was able to reduce the number of CFU/mL in biofilms and to cause structural alteration and cellular destruction, observed via SEM. A. colubrina showed low toxicity in the in vivo assay, having not affected the viability of the larvae at doses below 100mg/kg and high potential in the treatment of C. albicans infection. Considering its high antifungal potential, its low toxicity and potential to treatment of infections in in vivo model, A. colubrina extract is a strong candidate for development of a new agent for the treatment of oral candidiasis.

Anti-Candida and anti-quorum sensing activity of airborne microorganisms detected by a rapid method

Abstract INTRODUCTION: Introducing new antibiotics to the clinic is critical. METHODS: We adapted a plate method described by Kawaguchi and coworkers in 20131 for detecting inhibitory airborne microorganisms. RESULTS: We obtained 51 microbial colonies antagonist to Chromobacterium violaceum, purified and retested them, and of these, 39 (76.5%) were confirmed. They comprised 24 bacteria, 13 fungi, and 2 yeasts. Among the fungi, eight (61.5%) produced active extracts. Among the bacterial, yeast, and fungal strains, 17 (44.7%) and 12 (31.6%) were active against Candida albicans and Candida parapsilosis, respectively. CONCLUSIONS: The proposed screening method is a rapid strategy for discovering potential antibiotic producers.

ERG11 gene polymorphisms and susceptibility to fluconazole in candida isolates from diabetic and kidney transplant patients

Abstract INTRODUCTION: Candidiasis is the most frequent opportunistic mycosis in humans and can cause mortality, particularly in immunodeficient patients. One major concern is the increasing number of infections caused by drug-resistant Candidas trains, as these cannot be efficiently treated with standard therapeutics. The most common mechanism of fluconazole resistance in Candida is mutation of ERG11, a gene involved in the biosynthesis of ergosterol, a compound essential for cell integrity and membrane function. METHODS: Based on this knowledge, we investigated polymorphisms in the ERG11 gene of 3 Candida species isolated from immunocompromised and immunocompetent patients. In addition, we correlated the genetic data with the fluconazole susceptibility profile of the Candida isolates. RESULTS: A total of 80 Candida albicans, 8 Candida tropicalis and 6 Candida glabrata isolates were obtained from the saliva of diabetic, kidney transplant and immunocompetent patients. Isolates were considered susceptible to fluconazole if the minimum inhibitory concentration was lower than 8 μg/mL. The amino acid mutations F105L, D116E, K119N, S137L, and K128T were observed in C. albicans isolates, and T224C and G263A were found in C. tropicalis isolates. CONCLUSIONS: Despite the high number of polymorphisms observed, the mutations occurred in regions that are not predicted to interfere with ergosterol synthesis, and therefore are not related to fluconazole resistance.

Candida blankii: um patógeno emergente de difícil diagnóstico e tratamento clínico / Candida blankii: an emerging pathogen difficult to diagnose and to treat clinically

O gênero Candida possui várias espécies conhecidas e que podem tornar-se patogênicas em determinadas situações. Candida blankii é uma espécie emergente que, na última década, foi identificada como um agente de doenças sistêmicas. Ainda não existe um protocolo de tratamento específico, apesar de que n os poucos casos registrados na literatura a terapia adotada foi efetiva. O objetivo deste estudo foi realizar uma revisão bibliográfica para coletar informações relevantes sobre este patógeno como um possível agente etiológico em infecções sistêmicas, bem como sua epidemiologia e os aspectos de sua patogenicidade. (AU)

The genus Candida has several known species and may become pathogenic in certain situations. Candida blankii is an emerging species that in the past decade has been identified as an agent of systemic diseases. There is no specific treatment protocol yet, although in the few cases reported in the literature the therapy adopted was effective. The objective of this study was to conduct a literature review to collect relevant information about this pathogen as a possible etiological agent in systemic infections, as well as its epidemiology and aspects of pathogenicity. (AU)

Actinomicetos con actividad anti-candida aisladas de hormigas cortadoras de hojas Atta cephalotes (Formicidae: Myrmicinae: Attini) / Actinomyces with anti-candida activity isolated from leaf-cutting ants Atta cephalotes (Formicidae: Myrmicinae: Attini)

RESUMEN Objetivos. Aislar, seleccionar e identificar actinomicetos asociados a hormigas cortadoras de hojas Atta cephalotes (Linnaeus, 1758), que presenten mayor actividad anti-Candida. Materiales y métodos. Estudio transversal realizado en hormigas recolectadas de una localidad de Huánuco, Perú, a partir de las cuales se aislaron cepas de actinomicetos que fueron evaluadas mediante pruebas in vitro para determinar su capacidad antagonista frente a especies de Candida. Los actinomicetos de mayor antagonismo fueron seleccionados y cultivados en agitación, luego se obtuvieron los metabolitos extracelulares con solventes orgánicos y finalmente se evaluaron los extractos crudos para determinar cuantitativamente la concentración mínima inhibitoria (CMI). Resultados. Se logró aislar 30 actinomicetos, de los cuales el 47 % presentaron actividad antagonista a Candida albicans (C. albicans) ATCC 7516, el 43 % a Candida parapsilosis ATCC 7307, el 37% a Candida tropicalis ATCC 7206 y C. albicans ATCC 10231 y el 30% a C. albicans ATCC 98028. Extractos orgánicos de las cepas HAA-16 y HAA-17 presentaron marcada actividad anti-Candida; siendo el extracto de acetato de etilo de la cepa HAA17 el de mejor rendimiento por tener mayor espectro de actividad y presentar una CMI de 3,25 mg/ml frente a C. albicans ATCC 7516 y Candida parapsilosis ATCC 7307. Los actinomicetos seleccionados se identificaron mediante técnicas moleculares como miembros del género Streptomyces. Conclusiones. Los actinomicetos asociados a Atta cephalotes son excelentes productores de compuestos bioactivos, capaces de inhibir el crecimiento de levaduras patógenas del género Candida y con potencial aplicación en el desarrollo de nuevos productos naturales de interés biomédico.

ABSTRACT Objectives. To isolate, select and identify actinomyces associated to leaf-cutting ants Atta cephalotes (Linnaeus, 1758), that present a greater anti-Candida activity. Materials and Methods. Cross-sectional study made with ants collected at a location in Huánuco, Peru, from which strands of actinomyces were isolated and later evaluated by in vitro testing in order to determine its antagonistic capacity against species of Candida. The actinomyces with greater antagonism were selected and cultured by agitation, then the reliable extracellular metabolites were obtained with organic solvents, and finally the crude extracts were evaluated to determine quantitatively the minimum inhibiting concentration (MIC). Results. Thirty (30) actinomyces were isolated, of which 47% exhibited antagonistic activity against Candida albicans (C. albicans) ATCC 7516, 43% to Candida parapsilosis ATCC 7307, 37% to Candida tropicalis ATCC 7206 and C. albicans ATCC 10231, and 30% to C. albicans ATCC 98028. Organic extracts of the HAA-16 and HAA-17 strands exhibited noticeable anti-Candida activity, being the ethyl acetate extract of the HAA-17 strand the one with the highest performance thanks to a wider activity spectrum of MIC 3.25 mg/mL against C. albicans ATCC 7516 and Candida parapsilosis ATCC 7307. The selected actinomyces were identified by means of molecular techniques as members of the Streptomyces genus. Conclusions. Actinomyces associated to Atta cephalotes are excellent producers of bioactive compounds, being able to inhibit the growth of pathogenic mold of the Candida genus and with potential for application in the development of new natural products for the biomedical field.

Black and white teas as potential agents to combine with amphotericin B and protect red blood cells from amphotericin B-mediated toxicity / Chá preto e branco de Camellia sinensis como potenciais agentes para associar com anfotericina B

Abstract Amphotericin B is a fungicidal substance that is treatment of choice for most systemic fungal infections affecting immunocompromised patients. However, severe side effects have limited the utility of this drug. The aim of this study was to evaluate the antifungal effect of the combination of amphotericin B with black tea or white tea and protective of citotoxic effect. The present study shows that white and black teas have additive effects with amphotericin B against some species Candida. In addition, the combination of white and black tea with amphotericin B may reduce the toxicity of amphotericin B to red blood cells. Our results suggest that white and black tea is a potential agent to combine with amphotericin for antifungal efficacy and to reduce the amphotericin dose to lessen side effects.

Resumo A anfotericina B é o tratamento de escolha para a maioria das infecções fúngicas sistémicas que afetam os doentes imunocomprometidos. No entanto, efeitos secundários graves têm limitado a utilidade desta droga. O objetivo deste estudo foi avaliar o efeito antifúngico da combinação de anfotericina B com chá preto ou chá branco, bem como o efeito citotóxico desta combinação sobre hemáceas. O presente estudo demonstra que o chá branco e preto de Camellia sinensis têm efeitos aditivos com anfotericina B contra algumas espécies de Candida sp. Além disso, a combinação de chá branco e preto com anfotericina B pode reduzir a toxicidade da anfotericina B em hemáceas. Nossos resultados sugerem que o chá branco e preto são agentes potenciais para associação com anfotericina B contribuindo para eficácia antifúngica, bem como redução de toxicidade.

Identification and susceptibility of clinical isolates of Candida spp. to killer toxins / Identificação e susceptibilidade de isolados clínicos de Candida spp. para toxinas assassinas

Abstract Although invasive infections and mortality caused by Candida species are increasing among compromised patients, resistance to common antifungal agents is also an increasing problem. We analyzed 60 yeasts isolated from patients with invasive candidiasis using a PCR/RFLP strategy based on the internal transcribed spacer (ITS2) region to identify different Candida pathogenic species. PCR analysis was performed from genomic DNA with a primer pair of the ITS2-5.8S rDNA region. PCR-positive samples were characterized by RFLP. Restriction resulted in 23 isolates identified as C. albicans using AlwI, 24 isolates as C. parapsilosis using RsaI, and 13 as C. tropicalis using XmaI. Then, a group of all isolates were evaluated for their susceptibility to a panel of previously described killer yeasts, resulting in 75% being susceptible to at least one killer yeast while the remaining were not inhibited by any strain. C. albicans was the most susceptible group while C. tropicalis had the fewest inhibitions. No species-specific pattern of inhibition was obtained with this panel of killer yeasts. Metschnikowia pulcherrima, Pichia kluyveri and Wickerhamomyces anomalus were the strains that inhibited the most isolates of Candida spp.

Resumo Embora as infecções invasivas e a mortalidade causada por espécies de Candida estejam aumentando entre pacientes comprometidos, a resistência a agentes antifúngicos comuns também é um problema crescente. Analisamos 60 leveduras isoladas de pacientes com candidíase invasiva utilizando como estratégia PCR/RFLP baseada na região espaçadora transcrita interna (ITS2) para identificar diferentes espécies patogênicas de Candida. A análise por PCR foi realizada a partir de ADN genómico com um par de iniciadores da região ITS2-5.8S rDNA. As amostras PCR-positivas foram caracterizadas por RFLP. A restrição resultou em 23 isolados identificados como C. albicans usando AlwI, 24 isolados como C. parapsilosis usando RsaI e 13 como C. tropicalis usando XmaI. Em seguida, avaliou-se o grupo de todos os isolados quanto à sua susceptibilidade a um painel de leveduras killer previamente descritas, resultando em 75% sendo suscetíveis a pelo menos uma levedura killer, enquanto que as restantes não foram inibidas por qualquer cepa. C. albicans foi o grupo mais suscetível enquanto C. tropicalis teve o menor número de inibições. Não se obteve um padrão de inibição específico da espécie com este painel de leveduras killer. Metschnikowia pulcherrima, Pichia kluyveri e Wickerhamomyces anomalus foram as cepas que inibiram a maioria dos isolados de Candida spp.

Distribution of clinical isolates of Candida spp. and antifungal susceptibility of high biofilm-forming Candida isolates

Abstract INTRODUCTION: The increase in the incidence of fungal infections, especially those caused by Candida albicans and other Candida species, necessitates the understanding and treatment of Candida-associated infections. In this study, we aimed to investigate the identification, distribution, and biofilm formation ability of different clinical Candida isolates and evaluate the distribution and antifungal susceptibilities of high biofilm-forming (HBF) Candida isolates. METHODS: For identification, carbohydrate fermentation, carbohydrate assimilation, and ChromAgar tests were used. Biofilm formation was assessed using crystal violet binding assay, while the susceptibility to antifungal agents was determined using ATBTM Fungus 3 test kits. RESULTS: The majority of Candida species were C. parapsilosis (31.3%; 31/99) and C. tropicalis (30.3%; 30/99). C. tropicalis was found to be the most frequently isolated species among all HBF Candida species. HBF Candida isolates were more frequently isolated from vaginal swab (35.7%; 10/28), tracheal aspirate (17.9%; 5/28), and urine (17.9%; 5/28). The majority of tested isolates were resistant to itraconazole and voriconazole, whereas no isolate was deemed resistant to 5-flucytosine. CONCLUSIONS: C. tropicalis displays the highest biofilm formation ability among all the Candida species evaluated, and HBF Candida isolates were more frequently seen in vaginal swab, tracheal aspirate, and urine samples. Our findings revealed that 5-flucytosine is the most efficient antifungal agent against HBF Candida isolates.

In vitro antifungal susceptibility of Candida speciesisolated from diabetic patients

Abstract INTRODUCTION This study aims to evaluate the antifungal susceptibility of different species of Candida isolated from diabetic patients against eight antifungal agents. METHODS Susceptibility testing of 111 clinical isolates of Candida species was performed against 8 antifungals using the M27-A3 protocol of the Clinical and Laboratory Standards Institute (CLSI). RESULTS Voriconazole, lanoconazole, and caspofungin showed the highest in vitro activity against all the isolates of C. albicans. Resistance against the tested antifungals was only observed in the C. albicans isolates. CONCLUSIONS Our finding revealed that resistance against amphotericin B, itraconazole, ketoconazole, posaconazole, and fluconazole can be observed in C. albicans.

Lactoferrin, chitosan and Melaleuca alternifolia-natural products that show promise in candidiasis treatment

Abstract The evolution of microorganisms resistant to many medicines has become a major challenge for the scientific community around the world. Motivated by the gravity of such a situation, the World Health Organization released a report in 2014 with the aim of providing updated information on this critical scenario. Among the most worrying microorganisms, species from the genus Candida have exhibited a high rate of resistance to antifungal drugs. Therefore, the objective of this review is to show that the use of natural products (extracts or isolated biomolecules), along with conventional antifungal therapy, can be a very promising strategy to overcome microbial multiresistance. Some promising alternatives are essential oils of Melaleuca alternifolia (mainly composed of terpinen-4-ol, a type of monoterpene), lactoferrin (a peptide isolated from milk) and chitosan (a copolymer from chitin). Such products have great potential to increase antifungal therapy efficacy, mitigate side effects and provide a wide range of action in antifungal therapy.

Clinical and laboratorial features of oral candidiasis in HIV-positive patients

Abstract INTRODUCTION We describe the clinical and laboratorial features of oral candidiasis in 66 HIV-positive patients. METHODS: Polymerase chain reaction-based techniques were performed for differentiation of Candida spp. isolated from patients at a public teaching hospital in Midwest Brazil. RESULTS: Oral lesions, mainly pseudomembranous, were significantly related to higher levels of immunosuppression. Of 45 Candida isolates, 66.7% were C. albicans. Most of the isolates were susceptible to the antifungal drugs tested. CONCLUSIONS: Oral lesions were associated with higher immunosuppression levels. Lower susceptibility to antifungals by non-albicans isolates supports the importance of surveillance studies using susceptibility tests to aid in the treatment.

Antimicrobial, antioxidant and phytochemical assessment of wild medicinal plants from Cordillera Blanca (Ancash, Peru) / Evaluación antimicrobiana, antioxidante y fitoquímico de plantas medicinales silvestres de la Cordillera Blanca (Ancash, Perú)

Twenty-eight native plants mainly used to cure diseases related to microbial infection and stress oxidative disorders were selected to test the antimicrobial activity against E. coli, P. aeruginosa, S. aureus, B. subtilis, and C. albicans using diffusion and microdilution methods. The antioxidant activity was determined by scavenging DPPH free-radical and phytochemical evaluation was performed for plants with promising activities. Twenty-seven plants showed antibacterial activity, four had anti-Candida activity, and four showed antioxidant activity. It was found that Oreocallis grandiflora, Gentianella weberbaueri, Gamochaeta americana, Hypericum laricifolium, Loricaria ferruginea, Muehlenbeckia volcanica, and Oenothera multicaulis, showed promising biological activity and contained alkaloids, phenolic compounds, flavonoids, catecholic or gallic tannins. This study leaves evidence about the medicinal potential of wild high-Andean plants; thus, further pharmacological, phytochemical, ecological and biotechnological studies will contribute to promote their conservation and sustainable use; especially since they are highly vulnerable and risk extinction.

Se seleccionó veintiocho plantas nativas usadas principalmente para tratarcurar enfermedades relacionadas principalmente con infecciones microbianas y desordenes oxidativos. A estas plantas se para ser evaluóados en su actividad antimicrobiana sobre E. coli, P. auriginosa, S. aureus, B. subtilis, y C. albicans usando métodos de difusión y microdilución. Se determinó la actividad antioxidante mediante el ensayo del libre radical DPPH y se realizó la evaluación fitoquímica de las plantas con actividades promisorias. Veinte siete plantas mostraron actividad antibacteriana, cuatro mostraron actividad anti-Candida, y cuatro actividad antioxidante. Oreocallis grandiflora, Gentianella weberbaueri, Gamochaeta americana, Hypericum laricifolium, Loricaria ferruginea, Muehlenbeckia volcanica, y Oenothera multicaulis mostraron actividad biológica promisoria, y se encontró que contienen alcaloides, compuestos fenólicos, flavonoides, taninos gálicos y catecólicos. Este estudio deja evidencia del potencial medicinal de las plantas silvestres alto andinas; por lo tanto, los estudios farmacológicos, fitoquímicos, ecológicos y biotecnológicos contribuirían en la promoción de su conservación y uso sustentable debido a su alta vulnerabilidad y riesgo de extinción.

Antifungal activity of linalool in cases of Candida spp. isolated from individuals with oral candidiasis / Atividade antifúngica do linalol em casos de Candida spp. isolados de indivíduos com candidíase oral

Abstract This study analyzed the antifungal activity of phytoconstituents from linalool on Candida spp. strains, in vitro, isolated from patients with clinical diagnoses of oral candidiasis associated with the use of a dental prosthesis. Biological samples were collected from 12 patients using complete dentures or removable partial dentures and who presented mucous with diffuse erythematous or stippled features, indicating a clinical diagnosis of candidiasis. To identify fungal colonies of the genus Candida, samples were plated onto CHROMagar Candida®. The antifungal activity of linalool, a monoterpene unsaturated constituent of basil oil, was performed using the broth microdilution technique. Then, the minimum inhibitory concentration (MIC), the two subsequent stronger concentrations and the positive controls were subcultured on Sabouraud Dextrose Agar plates to determine the minimum fungicidal concentration (MFC). The experiments were performed in triplicate and nystatin was used as a positive control in all tests. Diagnoses of oral candidiasis were verified in eight patients (66.6%) and the most prevalent fungal species was Candida albicans (37.5%), followed by Candida krusei (25.0%); and Candida tropicalis (4.2%). The best antifungal activity of linalool was observed on Candida tropicalis (MIC = 500 mg/mL), followed by Candida albicans (MIC = 1.000 mg/mL), and Candida krusei (MIC = 2.000 mg/mL).Under the study conditions and based on the results obtained, it can be concluded that the Candida strains tested were susceptible to linalool.

Resumo Este estudo analisou a atividade antifúngica do fitoconstituinte linalol em cepas de Candida ssp, in vitro, isolados de pacientes com o diagnóstico clínico de candidíase oral associado ao uso de prótese dentária. As amostras biológicas foram coletadas de 12 pacientes portadores de próteses totais ou próteses parciais removíveis e que apresentavam características de mucosa eritematosa difusa ou pontilhadas, indicando um diagnóstico clínico de candidíase. Para identificar colônias de fungos do gênero Candida, as amostras foram semeadas em CHROMagar Candida®. A atividade antifúngica do linalol, um componente insaturado monoterpene de óleo de manjericão, foi realizada através da técnica de microdiluição em caldo. Em seguida, a concentração inibitória mínima (MIC), as duas concentrações consecutivas mais fortes e os controles positivos foram subcultivados em placas de Agar Sabouraud Dextrose para determinar a concentração fungicida mínima (MFC). Os experimentos foram realizados em triplicata e a nistatina foi usada como controle positivo em todos os testes. O diagnóstico de candidíase oral foi comprovado em oito pacientes (66,6%) e as espécies de fungos mais prevalentes foram Candida albicans (37,5%), seguido por Candida krusei (25,0%); e Candida tropicalis (4,2%). A melhor atividade antifúngica do linalol foi observada em Candida tropicalis (MIC = 500 mg/ml), seguido por Candida albicans (CIM = 1,000 mg/mL), e Candida krusei (CIM = 2,000 mg/mL). Sob as condições do estudo e com base nos resultados obtidos, pode-se concluir que as estirpes de Candida testadas foram susceptíveis a linalol.