Amphiphilic kanamycin is one of the promising class of compounds for the treatment of fungal infections in plants and animal. Factor that lead to the restricting of compounds for commercialization includes, the higher cost of production and poor stability of the compound. However, the new lead, identified from the synthesis and biological testing, can be synthesized on a large scale with a cost comparable to commercial antifungals. The newly reported lead is stable at the acidic and basic conditions. Additionally, this compound has an excellent activity towards Candida auris, a multidrug-resistant superbug. Heart disease is the leading cause of death in the United States most of which are caused by cardiac ischemia and arrhythmias. Abnormal opening of Cx43 hemichannel can damage the heart muscles and lead to these conditions. A compound which can selectively inhibit the opening of Cx43 hemichannel may pave the way to reducing the mortality rate of heart disease. A selective inhibitor towards Cx43 hemichannel is explored from the synthesis and biological testing of kanamycin derivatives. The synthesis of the new inhibitor is scalable and cost-effective.

>Magister Scientiae - MSc / Nanotechnology is spreading rapidly across the world as an extremely powerful technology. Nanoscience and nanotechnology are innovative scientific advancements that have been introduced only in this century. Nanotechnology has developed as the scientific advancement to grow and transform the entire agri-food area, with the potential to elevate global food production, in addition to the nutritional value, quality, and safety of food and food products. It has gained recognition due to its variability in shape, size, and dimension and how it correlates to its possibilities. One of those functions is nanoparticles’ (NPs) ability to have antimicrobial activity, more specifically its antifungal activity. One particular pathway of synthesising NPs is through phytonanotechnology which is the use of biomaterial to synthesis the NPs. / 2024

Orientador: Cristiane Yumi Koga-Ito / Resumo: A crescente incidência da resistência às drogas antifúngicas tornou-se um grande desafio para áreas médica e odontológica, fazendo com que a busca por métodos de tratamento alternativos ou em combinação com as já utilizadas sejam urgentemente necessárias. O objetivo deste projeto foi avaliar os efeitos da associação entre o plasma frio em pressão atmosférica e antifúngicos poliênicos convencionais utilizados no tratamento tópico da candidose bucal. Para tanto, foram realizados: a) Determinação das concentrações inibitórias dos antifúngicos poliênicos nistatina e anfotericina B e do plasma frio em pressão atmosférica sobre biofilmes de C. albicans; b) Avaliação do efeito dos tratamentos isolados e associados em condições/concentrações sub-inibitórias para fins de comparação e c) Avaliação dos diferentes protocolos de aplicação dos tratamentos, visando a obtenção da condição experimental mais eficaz para o controle do biofilme fúngico. Os dados de unidades formadoras de colônia foram comparados estatisticamente entre os grupos por One-way ANOVA e post hoc Tukey, com nível de significância de 5%. A partir dos resultados obtidos, pode-se concluir que o jato de plasma apresentou efeito antifúngico similar quando aplicado isoladamente ou em associação com nistatina e anfotericina B. Ainda, foi possível concluir que o jato de plasma frio apresenta efeito antifúngico mais eficaz do que os tratamentos dos biofilmes utilizando nistatina e anfotericina B no tempo de 5 minutos. / Abstract: The increasing incidence of antifungal resistance represents a great challenge in the medical areas and Dentistry. For this reason, the search for alternative methods or combination with the conventional ones is urgently necessary. The aim of this project is to evaluate, the effects of association between atmospheric pressure cold plasma and conventional polyene antifungals used for the treatment of oral candidiasis will be studied. With this purpose, the following methodologies were be used: a) To determine the inhibitory concentrations of the polyene antifungals nystatin and amphotericin B and cold plasma on C. albicans biofilms, b) To evaluate the combination of treatments in subinhibitory conditions, including isolated treatments for comparison purposes and c) To evaluate different protocols of treatment application, aiming to obtain the most effective protocol against fungal biofilm. Data was compared by One-way ANOVA and post hoc Tukey, with a significance level of 5%. Considering the results, it could be concluded that cold plasma showed similar effects when applied alone or in association to nystatin and amphotericin B. Cold plasma showed more effective antifungal effect on biofilms when compared to nystatin and amphotericin B, after 5 min exposure. / Mestre

Orientador: Maria Virginia Scarpa / Coorientador: Marcelo Gonzaga de Freitas Araújo / Banca : Luis Roberto Basso Junior / Banca : Leila Aparecida Chiavacci / Resumo: A curcumina é o constituinte majoritário encontrado no rizoma da planta Curcuma Longa L., e apresenta diversas atividades farmacológicas. Diversos estudos comprovaram que a curcumina possui excelente atividade antifúngica, sendo um princípio ativo natural promissor para o tratamento de doenças fúngicas. O objetivo específico deste trabalho foi o desenvolvimento de formulações contendo curcumina que possam ter ação contra a candidíase vulvovaginal (CVV). Para a análise estrutural das formulações foram utilizadas as técnicas de microscopia de luz polarizada, espalhamento de raios-X à baixo ângulos, difração de raios-X e comportamento reológico, sendo comprovado que os sistemas desenvolvidos apresentam características adequadas e satisfatórias para a aplicação pretendida e com propriedades mucoadesivas. O método analítico proposto para quantificação da curcumina foi revalidado e utilizado nos ensaios de estabilidade e liberação in vitro. As formulações desenvolvidas foram submetidas ao estudo de estabilidade preliminar, com o objetivo de garantir a segurança e eficácia das mesmas, e foi comprovada a estabilidade das formulações desenvolvidas. Posteriormente foram feitos os testes de liberação in vitro, para verificar a capacidade da curcumina de ser liberada a partir da formulação e exercer sua atividade farmacológica. O sistema emulsionado e o pseudoternário apresentaram taxas de liberação de 0,48% e 0,78% em 12 horas. A atividade farmacológica in vitro deste composto ativo, de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Curcumin is the main active compound found in rhizome of Curcuma Longa L. plant and has several pharmacological activities. Several studies have shown that curcumin has excellent antifungal activity and it is a promising natural active compound for treatment of fungal diseases. The research objective was formulations development containing curcumin that may have action against vulvovaginal candidiasis (VVC). For formulations structural analysis were used techniques as polarized light microscopy, small angle X-ray scattering, X-ray diffraction and rheological behavior, and the developed systems has presented adequate and satisfactory characteristics according with research objective and with mucoadhesive properties. The proposed analytical method for curcumin quantification was revalidated, then used in stability study and in vitro release assays. The formulations were submitted to a preliminary stability study to guarantee its safety and efficacy, this way stability was proven. Subsequently were performed in vitro release tests to verify the curcumin ability of release from formulations and to exert its pharmacological activity. The emulsified and pseudoternary systems presented release rates of 0.48% and 0.78% in 12 hours. With the in vitro pharmacological activity test was determined the minimal inhibitory concentration against yeast Candida albicans and also the effective concentration to be incorporated in the systems. After these tests was performed in vivo anti-VVC acti... (Complete abstract click electronic access below) / Mestre

Anecdotal evidence of two South African Geranium species (Pelargonium reniforme and Pelargonium sidoides) from the United Kingdom with regard to plants being used against tuberculosis, which lacked scientific evidence’ prompted us to investigate these two plants for their antimicrobial properties. The German herbal remedy (‘Umckaloabo’) is prepared from these two plant species and is currently being sold for bronchitis. Acetone, chloroform and ethanol extracts were investigated against three bacteria (pathogens causing bronchitis), three fungi (fungal species associated with the upper and lower respiratory tract) and Mycobacterium tuberculosis. This is the first report on the extracts’ activity against Moraxella catarrhalis, and three fungi (Asperigilus niger, Rhizopus stolonifer and Fusarium oxysporum). Acetone and ethanol root extracts of P. sidoides and its combination with P. reniforme exhibited activity against bacteria at 5.0 mg/ml concentration. The fungi were significantly inhibited by the acetone and ethanol extracts of P. reniforme and the ethanol extract of P. sidoides at a concentration of 5.0 mg/ml. Antituberculosis activity was observed on acetone, chloroform and ethanol root extract of P. reniforme and chloroform extract of P. sidoides at 5.0 mg/ml concentration. The isolation and purification of compounds were attempted using two different approaches, of which the second approach resulted in isolation of four compounds and two flavonoids. One flavonoid (epigallocatechin) is isolated for the first time from P. sidoides. Laboratory investigations showed no activity of compounds isolated against M. tuberculosis. As Mycobacteria are intracellular pathogens, antimycobacterial activities may be due to either direct or indirect effects. Though the compounds in this study did not show antituberculosis activity, it can be speculated that the anecdotal evidence of TB-patients could be due to their immunostimulant activity. / Dissertation (MSc (Plant Physiology))--University of Pretoria, 2005. / Plant Science / unrestricted

No description available.

Invasive aspergillosis (IA) is a major opportunistic fungal infection in patients with haematological malignancies. Morbidity and mortality rates are high despite anti-fungal treatment, as the compromised status of immune system prevents the host from responding optimally to conventional therapy. This raises the consideration for immunotherapy as an adjunctive treatment. In this study, we evaluated the utility of expanded human NK cells as treatment against Aspergillus fumigatus infection in vitro and in vivo. The NK cells were expanded and activated by K562 cells genetically modified to express 4-1BB ligand and membrane-bound interleukin-15 (K562-41BBL-mbIL-15) as feeders. The efficacy of these cells was investigated in A. fumigatus killing assays in vitro and as adoptive cellular therapy in vivo. The expanded NK cells possessed potent killing activity at low effector-to-target ratio of 2:1. Fungicidal activity was morphotypal-dependent and most efficacious against A. fumigatus conidia. Fungicidal activity was mediated by dectin-1 receptors on the expanded NK cells leading to augmented release of perforin, resulting in enhanced direct cytolysis. In an immunocompromised mice pulmonary aspergillosis model, we showed that NK cell treatment significantly reduced fungal burden, hence demonstrating the translational potential of expanded NK cells as adjunctive therapy against IA in immunocompromised patients.

The main aim of this study was to isolate and characterise antifungal and antibacterial compounds from leaf extracts of Combretum molle which belonging to the Combretaceae family. C. molle is one of the commonly used medicinal plants in southern Africa for numerous ailments. Three animal fungal pathogens, namely, Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus and five plant fungal pathogens, namely, Aspergillus niger, Aspergillus parasiticus, Fusarium oxysporum, Penicillium janthinellum, Rhizoctonia solani and four nosocomial bacteria Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa were used as test microorganisms for bioactive compounds in leaf extracts of C.molle. Experiments for phytochemical analysis were done using different C. molle leaf extracts which were made using acetone, methanol, ethanol, ethyl acetate, chloroform, butanol and hexane as extractants. Thin Layer Chromatography (TLC) fingerprints of different leaf extracts were developed in three mobile phase systems, EMW, CEF and BEA and detected with vanillin-sulphuric acid spraying agent. The different extracts of C. molle showed the presence of many different compounds with distinct retardation factors (Rf), separated according to their polarities. Bioautography was carried out to determine the number of active compounds and their Rf values. The TLC plates were developed in three mobile systems, each sprayed with either fungal or bacterial strains. In BEA bioautograms of A. fumigatus, clear zones of inhibition were observed at Rf values of 0.12, 0.23, and 0.40. In EMW bioautogram of C. albicans, clear zones of inhibition were observed at Rf value of 0.73, 0.81, 0.87. C. neoformans had weak growth inhibition. Most of the fungal and bacterial strains tested in the bioautography displayed susceptibility to the active compounds, with P. janthinellum and P. aeruginosa showing exceptional sensitivity. The minimum inhibitory concentrations (MIC) values ranged from 0.02 to 2.5 mg/ml against the tested pathogens. The acetone and ethyl acetate extracts had the best inhibitory activity against P. janthinellum with an MIC value of 0.02 mg/ml. The acetone extract of C. molle gave the highest total activity (775 ml/g) against P. janthinellum. C. albicans was the most resistant pathogen with an average MIC value of 0.56 mg/ml compared with the other tested strains. Extracts were active against both Gram-positive and Gram-negative strains. P. aeruginosa extracts had the highest average MIC value (0.24 mg/ml) among the tested bacterial strains. In general, there was good overall inhibitory activity by different extracts of C. molle. Bioassay-guided fractionation of DCM extract of the leaves of C. molle yielded 32 fractions. Further fractionation led to the isolation of five compounds (C1, C2, C3, C4 and C5). Compound C1 was selected for structure elucidation due a larger quantity isolated and higher antimicrobial activity compared with the other isolated compounds. Nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy (MS) was used to show that compound C1 was taraxerol, belonging to the taraxerane group. Antimicrobial activity of the isolated compound against P. janthinellum had an MIC value of 0.08 ug/ml. Although the compound taraxerol have been discovered in other plant species, it is reported for the first time from C. molle in the study. The results illustrate that crude extracts and compound taraxerol from C. molle can be used as either an antibacterial or antifungal, and warrants further investigation. / Dissertation (MSc)--University of Pretoria, 2017. / Paraclinical Sciences / MSc / Unrestricted

Candida albicans is a fungal microorganism found on the human body and in the environment. An opportunistic pathogen causing local and systemic infection, this fungus is one of the leading causes of nosocomial infections. More alarming is its growing resistance against the limited number of antifungals we have for treatment Candida infections. An area of current research, termed polymicrobial interactions, focuses on how different microorganisms interact with each other for limited space, nutrients, and survival. The current study focuses on attempting to inhibit planktonic and biofilm growth stages by using the benign bacterium Alcaligenes faecalis, previously shown in our lab to kill C. albicans. Under a variety of growth conditions and phases, co-cultures of A. faecalis and C. albicans have demonstrated that the bacterium drastically inhibits all forms of Candida growth. The results of this study may provide information on potential new therapeutic targets that Alcaligenes may employ in inhibition of Candida.

Strains MS455 and MS389, endophytic bacteria, were isolated from healthy soybean plant growing adjacent to a patch of plants affected by charcoal rot disease, caused by the fungal pathogen Macrophomina phaseolina. The complete genomes of both strains were sequenced and identified as Burkholderia species Strain MS455 exhibits broad-spectrum antifungal activities against economically important pathogens, including Aspergillus flavus. Random and site-specific mutations were employed in discovery of the genes that share high homology to the ocf gene cluster of Burkholderia contaminans strain MS14, which is responsible for production of the antifungal compound occidiofungin. RNA-seq analysis demonstrated ORF1, a homolog to the ambR1 LuxR-type regulatory gene, not only regulates occidiofungin biosynthesis in MS455, but also involved in expression of multiple genes, especially those involved in ornibactin biosynthesis. Plate and corn kernel assays showed that growth of A. flavus and aflatoxin production were reduced significantly by MS455 as compared with buffer control and the ORF1 mutant. Strain MS389 shows significant antifungal and antibacterial activities as well. Mutagenesis study identified that the TatC gene, an important unit of twin-arginine translocase (Tat) secretion system, and the LysR-type transcriptional regulatory gene were essential for the antifungal activity of strain MS389. RNA-seq analysis implied that the pyrrolnitrin biosynthesis gene cluster and an uncharacterized NRPS / PKS gene cluster were involved in antifungal activity. By comparing several endophytic bacteria of Burkholderia, including MS455 and MS389, to pathogenic Burkholderia species, endophytic bacteria were observed to harbor multiple antimicrobial biosynthesis genes but lack certain pathogenic or virulence genes. The potential endophytic behavior related genes and characteristics related to antibiotic resistance, secretion system, and CRISPR-Cas profiles were well established. The research findings on strains MS455 and MS389 have provided important genetic clues for understanding their molecular mechanism of antimicrobial activities and exhibited their potential possibility as biocontrol agents.