Popchai NgamskulrungrojIyarit ThaipisutikulPhoom ChairatanaChalermchai MitrpantPokhrel, Sabi, 1991-2026-01-082026-01-08202220262022Thesis (Ph.D. (Medical and Molecular Microbiology))--Mahidol University, 2022)https://repository.li.mahidol.ac.th/handle/123456789/113830Candida albicans, an opportunistic pathogen, has the ability to form biofilm in the host or within the indwelling medical devices in their body. Biofilm has been associated with the disseminated disease with increased severity of infection by perturbing host immune response and prolonging the antifungal treatment. In this study, three strains with different biofilm-forming strengths, i.e., non- , weak- , and strong biofilm formers were assessed for in vivo virulence using the zebrafish model. Survival assay and fungal tissue burden were measured. Biofilm-related and immune- related gene expressions were also investigated. Survival of the zebrafish, inoculated with strong biofilm forming C. albicans, was significantly shorter compared to non- biofilm forming C. albicans strains. However, there was no statistical difference in colony forming unit tissue burden among groups of all three tested strains. We observed that C. albicans with different biofilm-forming in vitro capacity induced significantly different levels of biofilm-related genes associated with strains and showed significant differences in biofilm-related gene expression at an early time- point (8 h). Biofilm forming strain (140 and 57), injected in zebrafish larvae, possessed higher expression levels of genes associated with adhesion, attachment, filamentation, and cell proliferation, including eap1, als3, hwp1, bcr1, efg1, and mkc1 as well as genes associated with maturation (zap1), and dispersion (ume6 and nrg1). Furthermore, immune-related genes such as il-6, tgfb1r, tnf-α, and foxp3a were also up-regulated in zebrafish infected with strong biofilm forming strain at 24 h. The results suggested that despite different genetic backgrounds, biofilm formation is an important virulence factor for the pathogenesis of C. albicans. However, the association between the biofilm-forming strength and in vivo virulence based upon immune response is still controversial and needs to be further studied.xiii, 110 leaves : ill.application/pdfengผลงานนี้เป็นลิขสิทธิ์ของมหาวิทยาลัยมหิดล ขอสงวนไว้สำหรับเพื่อการศึกษาเท่านั้น ต้องอ้างอิงแหล่งที่มา ห้ามดัดแปลงเนื้อหา และห้ามนำไปใช้เพื่อการค้าCandida albicans -- PathogenicityCandida albicans -- ImmunologyBiofilms -- Formation.Doctoral ThesisMahidol University