<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>

In C. albicans, a MAP kinase pathway has been implicated in aspects of controlling hyphal development. We have examined the transcription profile of cells deleted for the transcription factor Cph1 as well as Cst20, Hst7 and Cek1, three upstream kinases potentially involved in Cph1 regulation. Deletion of these four elements does not block filament induction by serum and does not dramatically affect the transcription profile of yeast-hyphal transition, but deletion of CPH1 delays filamentation. Over-expression of Cph1 by ADH1pt-CPH1 significantly enhances filamentation, suggesting that Cph1 is helpful but not essential for filament induction. Interestingly, the transcription profile of ADH1pt-CPH1 expressing cells under yeast conditions is similar to that of wild type strains undergoing the yeast-hyphal transition. Finally, it appears that Cek1 and its regulators Hst7 and Cst20 may control the repression of genes such as CHT2 through a process independent of the Cph1p transcription factor.

Thesis (M.Sc.). / Written for the Dept. of Biochemistry. Title from title page of PDF (viewed 2008/07/30). Includes bibliographical references.

Thesis (PhD (Phytomedicine Programme) (Paravet. Studies))--University of Pretoria, 2008. / Includes bibliographical references. Also available in print format.

Thesis (M.Sc. (Maxillofacial Prosthetics))--Mahidol University, 2007. / LICL has E-Thesis 0024 ; please contact computer services. LIRV has E-Thesis 0024 ; please contact circulation services.

Thesis (M.Sc. (Maxillofacial Prosthetics))--Mahidol University, 2008.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 75-85).

Thèse (M.Sc.)--Université Laval, 2004. / Bibliogr.: f. [102]-111. Publié aussi en version électronique.

Thèse (M.Sc.)--Université Laval, 2003. / Bibliogr.: f. [87]-103. Publié aussi en version électronique.

Submitted by LEANDRO WAGNER FIGUEIRA null (leandrowf@live.com) on 2017-12-21T15:14:01Z No. of bitstreams: 1 TRABALHO IMPRESSÃO.pdf: 1390929 bytes, checksum: 89bf6ffe02866e87b54f92901cd88b62 (MD5) / Approved for entry into archive by Silvana Alvarez null (silvana@ict.unesp.br) on 2018-01-04T15:29:14Z (GMT) No. of bitstreams: 1 figueira_lw_me_sjc.pdf: 1390929 bytes, checksum: 89bf6ffe02866e87b54f92901cd88b62 (MD5) / Made available in DSpace on 2018-01-04T15:29:14Z (GMT). No. of bitstreams: 1 figueira_lw_me_sjc.pdf: 1390929 bytes, checksum: 89bf6ffe02866e87b54f92901cd88b62 (MD5) Previous issue date: 2017-12-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os seres humanos vivem em constante relação com micro-organismos, comensais e patogênicos, que podem ameaçar a homeostase do hospedeiro. Espécies patogênicas apresentam mecanismos capazes de contornar as barreiras de defesa do hospedeiro, facilitando sua disseminação e proliferação nos tecidos invadidos. Cepas resistentes aos antimicrobianos disponíveis surgem diariamente, por isso, é relevante encontrar métodos alternativos para controla-las. Produtos de plantas medicinais vem sendo investigados para essa finalidade. No presente estudo, foi avaliada a capacidade do extrato de C. longa em controlar infecções in vitro por S. aureus, P. aeruginosa e C. albicans em macrófagos murinos (RAW 264.7). Para isto, foram aplicadas as concentrações inibitórias mínimas (CIM) do extrato vegetal nas infecções e por meio de análise da fagocitose foi analisado a contribuição delas para a eliminação destes micro-organismos. A viabilidade dos macrófagos foi analisada por meio de teste colorimétrico com corante vermelho neutro. Foram checadas a produção de citocinas inflamatórias (IL-1β, IL-6, TNF-α e IL-10) e óxido nítrico (NO), por ELISA e com reagente de Griess, respectivamente. Os resultados foram analisados por ANOVA e Tukey’s Test (P ≤ 0.05). Foi verificado que o extrato de C. Longa auxiliou de maneira efetiva os macrófagos na fagocitose dos micro-organismos avaliados, apresentando reduções significativas de unidades formadoras de colônia por mililitro (UFC/mL), e atuou mediação da síntese de citocinas e NO. Os macrófagos apresentaram-se viáveis durante a infecção. Desta forma, foi constatado que o extrato de C. longa foi capaz de auxiliar in vitro os macrófagos na eliminação de S. aureus, P. aeruginosa e C. albicans, além de proporcionar efeito imunomodulador na síntese de IL-1β, TNF-α, IL-10 e NO, no intuito de controlar as infecções microbianas in vitro.