"8th July 2002." Includes bibliographical references (leaves 276-308) Examines the systematics (taxonomy, phylogeny, and epiemiology) of the genus Candida using a combination of traditional and contemporary methodologies. Assesses these methods to determine their diagnostic potential to unequivocally identify and characterise species and strains of this medically and dentally important yeast genus.

"8th July 2002." / Includes bibliographical references (leaves 276-308) / vi, 308, [57] leaves : charts ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines the systematics (taxonomy, phylogeny, and epiemiology) of the genus Candida using a combination of traditional and contemporary methodologies. Assesses these methods to determine their diagnostic potential to unequivocally identify and characterise species and strains of this medically and dentally important yeast genus. / Thesis (Ph.D.)--University of Adelaide, Dept. of Dentistry, 2002

<p>The reproductive health of individuals is severely compromised by HIV infection, with candidiasis being the most prevalent oral complication in patients. Although not usually associated with severe morbidity, oropharyngeal candidiasis can be clinically significant, as it can interfere with the administration of medications and adequate nutritional intake, and may spread to the esophagus. Azole antifungal agents are commonly prescribed for the treatment and prophylaxis of candidal infections. However, the emergence of drug resistant strains and dose limiting toxic effects have complicated the treatment of candidiasis. Consequently, safe and effective and affordable medicine is required to combat this fungus. Commercial garlic (Allium sativum) has been used time since immemorial as a natural antibiotic, however very little is known about the antifungal properties of two indigenous South African species of garlic, namely Tulbaghia alliacea and Tulbaghia violacea, that are used as folk medicines for a variety of infections. This study compares the in vitro anti-candidal activity of Tulbaghia alliacea, Tulbaghia violacea and Allium sativum extracts. It was found that the greatest concentrations of inhibitory components were extracted by chloroform or water. The IC50 concentrations of Tulbaghia alliacea were between 0.007 &ndash / 0.038% (w/v). Assays using S. cerevisiae revealed that the T. alliacea extract was fungicidal, with a killing half-life of approximately 2 hours. This inhibitory effect of the T. alliacea extracts was observed via TLC, and may be due to an active compound called Marasmicin, that was identified using NMR. This investigation confirms that extracts of T.alliacea exhibit anti-infective activity against candida species in vitro.</p>

Methionine synthases catalyze methyl transfer from 5-methyl-tetrahydrofolate (5-methyl-THF) to L-homocysteine (Hcy) in order to generate methionine (Met). Mammals, including humans, use a cobalamin dependent form, while fungi use a cobalamin independent protein called Met6p. The large structural differences between them make Met6p a potential anti-fungal drug target. Met6p is a 90 kDa protein with the active site located between two (βα)₈ barrels. The active site has a catalytic Zn²+ and binding sites for the two substrates, Hcy and folate. I present the crystal structures of three engineered variants of the Met6p enzyme from Candida albicans. I also solved Met6p in complex with several substrate and product analogs, including Hcy, Met, Gln, 5-methyl-THF-Glu₃ and Methotrexate-Glu₃ (MTX-Glu₃), and the bi-dentate ligand S-adenosyl homocysteine. Also described is a new fluorescence-based activity assay monitoring Hcy. Lastly, a high-throughput Differential Scanning Fluorimetry (DSF) assay was used to screen thousands of compounds in order to identify ligands which bind Met6p. My work details the mode of interaction of Hcy and folate with the Met6p protein. Several residues important to activity were discovered, like Asn 126 and Tyr 660, and proven to be important by site directed mutagenesis. Structural analysis revealed an important aspect of the mechanism. When Hcy binds to its pocket it makes strong ion pairs with the enzyme. In particular, 614 moves toward the substrate amine and triggers a rearrangement of active site loops; this draws the catalytic Zn²+ toward the Hcy thiol where a new ligand bond is formed, activating the thiol for methyl transfer. The work presented here lays the groundwork for structure based drug design and makes the development of Met6p specific bi-dentate ligands feasible. The fluorescence based activity assay I developed was successfully used to test the folate analog MTX-Glu₃, which inhibits with an IC₅₀ of ~4 mM. I also discovered our first bi-dentate ligand in the form of S-adenosyl homocysteine. / text

<p>The reproductive health of individuals is severely compromised by HIV infection, with candidiasis being the most prevalent oral complication in patients. Although not usually associated with severe morbidity, oropharyngeal candidiasis can be clinically significant, as it can interfere with the administration of medications and adequate nutritional intake, and may spread to the esophagus. Azole antifungal agents are commonly prescribed for the treatment and prophylaxis of candidal infections. However, the emergence of drug resistant strains and dose limiting toxic effects have complicated the treatment of candidiasis. Consequently, safe and effective and affordable medicine is required to combat this fungus. Commercial garlic (Allium sativum) has been used time since immemorial as a natural antibiotic, however very little is known about the antifungal properties of two indigenous South African species of garlic, namely Tulbaghia alliacea and Tulbaghia violacea, that are used as folk medicines for a variety of infections. This study compares the in vitro anti-candidal activity of Tulbaghia alliacea, Tulbaghia violacea and Allium sativum extracts. It was found that the greatest concentrations of inhibitory components were extracted by chloroform or water. The IC50 concentrations of Tulbaghia alliacea were between 0.007 &ndash / 0.038% (w/v). Assays using S. cerevisiae revealed that the T. alliacea extract was fungicidal, with a killing half-life of approximately 2 hours. This inhibitory effect of the T. alliacea extracts was observed via TLC, and may be due to an active compound called Marasmicin, that was identified using NMR. This investigation confirms that extracts of T.alliacea exhibit anti-infective activity against candida species in vitro.</p>

<p>&nbsp / </p> <p align="left">One of the most common HIV-associated opportunistic infections is candidiasis, caused by <i><font face="TimesNewRoman,Italic">Candida albicans </font></i><font lang="KO" face="TimesNewRoman">or other </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species. In immune suppressed subjects, this commensal organism can cause an increase in patient morbidity and mortality due to oropharyngeal or systemic dissemination. Limited information exists on the prevalence and antifungal susceptibility of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species in the African continent, the most HIV-affected region globally and home to new and emerging drug resistant </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species. The mechanisms of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">drug resistance in the African continent have also not been described. In this study, 255 </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species isolated from the oral mucosa of HIV-positive South African and Cameroonian patients were identified using differential and chromogenic media and their drug susceptibility profiles tested using the disk diffusion method and the TREK Sensititre system, an automated broth microdilution method. </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">cell wall fractions were run on SDSPAGE and HPLC-MS with the aim of identifying peptides specifically expressed by antifungal drug resistant isolates. Comparisons between the two groups of isolates revealed differences in </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species prevalence and drug susceptibility with interesting associations observed between specific drug resistance and duration of ARV therapy. This study showed that fluconazole, the drug of choice for the treatment of candidiasis in the African continent, is not an effective therapy for most cases of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">infection, and suggests that regional surveillance be implemented in the continent. A multiple-drug resistant </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">strain was identified in this study, a finding that has not previously been documented. The use of proteomics tools allowed for the identification of peptides involved in drug resistance and the elucidation of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">colonization mechanisms in HIV-infected African patients.</font></i></i></i></i></i></i></i></i></i></i></p>

<p>&nbsp / </p> <p align="left">One of the most common HIV-associated opportunistic infections is candidiasis, caused by <i><font face="TimesNewRoman,Italic">Candida albicans </font></i><font lang="KO" face="TimesNewRoman">or other </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species. In immune suppressed subjects, this commensal organism can cause an increase in patient morbidity and mortality due to oropharyngeal or systemic dissemination. Limited information exists on the prevalence and antifungal susceptibility of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species in the African continent, the most HIV-affected region globally and home to new and emerging drug resistant </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species. The mechanisms of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">drug resistance in the African continent have also not been described. In this study, 255 </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species isolated from the oral mucosa of HIV-positive South African and Cameroonian patients were identified using differential and chromogenic media and their drug susceptibility profiles tested using the disk diffusion method and the TREK Sensititre system, an automated broth microdilution method. </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">cell wall fractions were run on SDSPAGE and HPLC-MS with the aim of identifying peptides specifically expressed by antifungal drug resistant isolates. Comparisons between the two groups of isolates revealed differences in </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species prevalence and drug susceptibility with interesting associations observed between specific drug resistance and duration of ARV therapy. This study showed that fluconazole, the drug of choice for the treatment of candidiasis in the African continent, is not an effective therapy for most cases of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">infection, and suggests that regional surveillance be implemented in the continent. A multiple-drug resistant </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">strain was identified in this study, a finding that has not previously been documented. The use of proteomics tools allowed for the identification of peptides involved in drug resistance and the elucidation of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">colonization mechanisms in HIV-infected African patients.</font></i></i></i></i></i></i></i></i></i></i></p>

Thesis (M. Sc.)--Université Laval, 1999. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M. Sc.)--Université Laval, 1999. / Includes bibliographical references.

Made available in DSpace on 2015-05-14T12:56:09Z (GMT). No. of bitstreams: 1 parte1.pdf: 4341478 bytes, checksum: eb878149d43f55e365452357e6cb9560 (MD5) Previous issue date: 2019-12-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Objective: To evaluate the effectiveness of the gel Cymbopogon citratus (DC.) Stapf (lemon grass) in the treatment of oral candidiasis in patients weares of prosthesis, comparing the results with Daktarin® oral gel. To this end, we carried out a randomized, blinded, controlled. Methods: The sample consisted of 30 adult patients, volunteers of both sexes, who underwent clinical examination and laboratory tests (mycological) for diagnosis of oral candidiasis. Patients were randomly assigned to experimental group consisted of 20 patients who used the gel Cymbopogon citratus and control group comprised 10 patients who used Daktarin® oral gel. Both requirements were recommended for use three times daily for a period of 15 days. Clinical and mycological analysis of the oral mucosa were performed on day 1 before the start of treatment in the 8th and the 16th day after initiation of medication. Analysis was performed using descriptive statistics and applied chisquare and Kruskal-Wallis test, considering significant p <0.05. Results: In the experimental group after 15 days of treatment, 80% of patients were cured in the control group and the healing occurred in 90% of patients. Candida albicans was the most prevalent (76.6%). Conclusions: According to the results obtained in clinical research concluded that the gel base of the essential oil from leaves of Cymbopogon citratus was effective in the treatment of oral candidiasis in prosthesis users. The results are promising and indicate this as an alternative herbal treatment for oral candidiasis. / Objetivo: Avaliar a eficácia do gel de Cymbopogon citratus (DC.) Stapf (capim santo) no tratamento da candidose bucal em pacientes usuários de prótese, comparando os resultados com o Daktarin® gel oral. Para tanto, realizou-se um estudo randomizado, cego, controlado. Material e método: A amostra foi constituída por 30 pacientes adultos, voluntários, de ambos os sexos, submetidos a exame clínico e laboratorial (micológico) para diagnóstico de candidose bucal. Os pacientes foram distribuídos aleatoriamente em grupo experimental, composto por 20 pacientes que utilizaram o gel de Cymbopogon citratus e grupo controle, composto por 10 pacientes que utilizaram Daktarin® gel oral. Ambas as prescrições foram recomendadas para uso 3 vezes ao dia, durante um período de 15 dias. Avaliações clínicas e micológicas da mucosa bucal foram realizadas no 1° dia antes do início do tratamento, no 8º e no 16º dia após o início da medicação. Realizou-se análise estatística descritiva e aplicou-se teste qui-quadrado e teste kruskal-wallis, considerando significante p<0,05. Resultados: No grupo experimental, após 15 dias de tratamento, 80% dos pacientes obtiveram cura e no grupo controle a cura ocorreu em 90% dos pacientes. A Candida albicans foi a espécie mais prevalente (76,6%). Conclusões: De acordo com os resultados obtidos nessa pesquisa clínica conclui-se que o gel a base do óleo essencial das folhas de Cymbopogon citratus foi eficaz no tratamento da candidose bucal em usuários de prótese. Os resultados são promissores e indicam este fitoterápico como uma alternativa de tratamento para candidose bucal.