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020 ▼a 9781687972927
035 ▼a (MiAaPQ)AAI10846768
040 ▼a MiAaPQ ▼c MiAaPQ ▼d 247004
0820 ▼a 574
1001 ▼a Dominguez, Eddie Gonzalez, Jr.
24510 ▼a Regulation and Function of the Extracellular Matrix in Candida Species Biofilms.
260 ▼a [S.l.]: ▼b The University of Wisconsin - Madison., ▼c 2018.
260 1 ▼a Ann Arbor: ▼b ProQuest Dissertations & Theses, ▼c 2018.
300 ▼a 197 p.
500 ▼a Source: Dissertations Abstracts International, Volume: 81-04, Section: B.
500 ▼a Advisor: Andes, David R.
5021 ▼a Thesis (Ph.D.)--The University of Wisconsin - Madison, 2018.
506 ▼a This item must not be sold to any third party vendors.
520 ▼a Believed to be the predominant microbial growth form found in nature, biofilms are an organized community of microorganisms residing on a surface embedded in extracellular matrix (ECM). In pathogens the ECM acts as a protective barrier against the host innate immune response and enhances drug resistance. Candida infections have the highest mortality rates of all nosocomial infections due to their ability to form difficult to treat biofilms on indwelling medical devices. Prior studies of the C. albicans matrix implicated the polysaccharides 慣-mannan and 棺-glucan, which forms a mannan-glucan complex (MGCx), as having a role in the high levels of drug resistance associated with biofilms. However, mechanisms of resistance involving the ECM of Candida tropicalis, Candida parapsilosis, and Candida glabrata bifoilms still remain unclear. This work utilized biochemical, pharmacological, and genetic approaches to identify mechanisms of resistance in these non-albicans Candida (NAC) species with respect to the ECM. Enzymatic inhibition or hydrolyzation of either of these polysaccharides resulted in increased susceptibility to antifungal drug treatments. These results suggested a conserved matrix structure and function among these Candida species. Genes known to regulate production and modification of the polysaccharide component of the ECM, in C. albicans, were knocked out in each of the NAC species. Biochemical analysis of wild-type NAC species matrices revealed the presence of the previously identified MGCx featuring a structurally conserved polysaccharide backbone of 慣-1,6-mannan and 棺-1,6-glucan. These results argue for a conserved functionality of the ECM among the species. Components of the ECM are theorized to be produced within the cell, packaged into extracellular vesicles (EVs), exported from within the cell, and constructed extracellularly through a number of proteins and enzymes. Here we use mutants defective in the endosomal sorting complexes required for transport (ESCRT) pathway to measure ECM carbohydrate content and function. A subset of defective mutants showed decreased levels of mannan/glucan, decreased quantity of EVs and enhanced susceptibility to antifungal drug treatments. These results argued that in C. albicans biofilms EVs are not only capable of cell-cell communication, as commonly seen in many organisms, but are also responsible for matrix production and biofilm drug resistance.
590 ▼a School code: 0262.
650 4 ▼a Microbiology.
650 4 ▼a Molecular biology.
690 ▼a 0410
690 ▼a 0307
71020 ▼a The University of Wisconsin - Madison. ▼b Cellular & Molecular Pathology.
7730 ▼t Dissertations Abstracts International ▼g 81-04B.
773 ▼t Dissertation Abstract International
790 ▼a 0262
791 ▼a Ph.D.
792 ▼a 2018
793 ▼a English
85640 ▼u http://www.riss.kr/pdu/ddodLink.do?id=T15490346 ▼n KERIS ▼z 이 자료의 원문은 한국교육학술정보원에서 제공합니다.
980 ▼a 202002 ▼f 2020
990 ▼a ***1008102
991 ▼a E-BOOK