Saudi Cultural Missions Theses & Dissertations
Permanent URI for this communityhttps://drepo.sdl.edu.sa/handle/20.500.14154/10
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Item Restricted Part 1: Studies on the Microbial Community profile of Two Caves in Greece and Slovakia. Part 2: Studies on the effect of Geographical and environmental factors on tea metabolites profile.(Saudi Digital Library, 2023-11-06) Almutari, Saleh; Kumaresan, Deepak; Di, WuThis comprehensive study delves into two distinct, yet interconnected realms of scientific inquiry: the microbiology of cave ecosystems and the metabolomics of tea. The first part of the study focuses on the microbial diversity in cave ecosystems, specifically in Crete (Greece) and Slovakia. Utilizing advanced techniques such as Oxford Nanopore Technologies for DNA sequencing and MicrobiomeAnalyst for data analysis, the research uncovers the complex microbial communities within these caves. Key findings include the dominance of certain microbial families like Sphingomonadaceae and the variation in microbial diversity between different cave locations. The study highlights the significant role of these microorganisms in cave ecosystems and sheds light on their potential biotechnological applications. The second part of the research investigates the impact of environmental and geographic factors on the metabolome profile of tea. Employing methods such as Liquid Chromatography-Mass Spectrometry (LC-MS) and Geographical Information Systems (GIS), the study examines how factors like altitude, soil composition, and climate affect the metabolite composition of tea. The results reveal distinct metabolomic fingerprints for teas from different geographic locations, underscoring the influence of environmental conditions on tea's flavor, aroma, and health benefits. The study contributes valuable insights into the metabolomics of tea and its implications for the tea industry, conservation, and health research. Overall, this dual-focused study bridges the gap between microbial ecology and plant metabolomics, offering a holistic view of the biological diversity in both subterranean and agricultural environments.14 0Item Restricted The Etiology of Peri-implantitis: Microbiological Profile Within and Around Dental Implants and the Associated Human Immune Response(2023) Kensara, Anmar; Masri, RadiObjectives: To characterize the microbiome composition within and around dental implants of peri-implantitis subjects and within and around healthy implants using 16S rRNA gene sequencing, and to profile salivary inflammatory mediators associated with peri-implantitis compared to healthy controls from the same subjects. Methods: A total of 24 subjects (peri-implantitis n=14, healthy n=10) were enrolled in the study. From the 24 subjects, 24 endosseous implants from affected (peri-implantitis) and 14 healthy controls were included in this cross-sectional study. Samples for microbiological analysis were obtained from the internal surfaces of dental implants and peri-implant sulcus using sterile paper points. DNA was extracted and 16S rRNA gene was amplified using universal primers targeting the V3-V4 regions. Amplicons were sequenced using Illumina MiSeq platform. Alpha and beta diversity, core microbiome, and taxa differential abundance were assessed. Saliva was collected from the same subjects for immunology-based assays. Salivary inflammatory mediators in peri-implantitis and healthy implant subjects were profiled using antibody arrays. Results: A significant increase in microbial diversity was observed in the internal implant surface of healthy implants compared with the internal surfaces of peri-implantitis (Shannon P= 0.02), and no significant differences in microbial diversity between healthy implants sulci and peri-implantitis pockets (Shannon P= 0.82). Bacterial community structure was significantly different within implant in both healthy and peri-implantitis groups (P= 0.012) but not significantly different around implants in both healthy and peri-implantitis (P= 0.18). Enterococci is the predominant bacteria within peri-implantitis (LD >2.0, P< 0.05). Abundant species in peri-implantitis were C. leadbetteri, T. maltophilum, Peptostreptococcus, Neisseria, P. gingivalis, and P. endodontali, L. lactis and F. alocis (P < 0.05). Gram-positive bacteria such as S. salivaris, P. melaninogenica, L. wadei, and Actinomyces spp were more abundant in the peri-implant healthy sulcus. Around 48% of detected bacteria were cultivable in general media. In addition, out of 105 analytes examined in saliva, we found that 29 mediators were upregulated in subjects with peri-implantitis (P < 0.001). Conclusions: Our results indicate that microbial colonization of the internal implant surface may act as a major contributor to the etiology of peri-implant disease. Multiple inflammatory mediators were significantly elevated in the saliva of peri-implantitis patients compared to healthy implant patients.30 0