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Full-Text Articles in Organisms

The Effect Of Fluorouracil On Pathogenic And Non-Pathogenic Oral Microorganisms And Microbial Interactions With Preventative Measures: A Preliminary Study, Valeria Ortiz Jimenez, Lynn Lewis Apr 2023

The Effect Of Fluorouracil On Pathogenic And Non-Pathogenic Oral Microorganisms And Microbial Interactions With Preventative Measures: A Preliminary Study, Valeria Ortiz Jimenez, Lynn Lewis

Student Research Submissions

Cancer chemotherapy compromises the patient’s oral health through dysbiosis of oral microbiota and increases the prevalence of dental cavities, gingivitis, oral mucositis, and xerostomia. This research aimed to evaluate the effect of a common chemotherapeutic agent, Fluorouracil (5-FU), on certain microorganisms that are common within the oral cavity. Varying concentrations (50 μM, 75 μM and 100μM) of 5-FU were used to simulate the dosage that reaches the oral cavity after intravenous delivery. The microorganisms tested were Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, Lactobacillus rhamnosus and Streptococcus salivarius. These are some of the most common ones found in the …


The Role Of Manganese In Streptococcus Sanguinis, Tanya M. Puccio Jan 2020

The Role Of Manganese In Streptococcus Sanguinis, Tanya M. Puccio

Theses and Dissertations

Streptococcus sanguinis is primarily associated with oral health as a commensal bacterium. As an opportunistic pathogen, S. sanguinis is capable of colonizing heart valve vegetations, leading to the disease infective endocarditis. Previous studies from our lab have identified the high-affinity manganese transporter SsaACB as important for endocarditis virulence. The impact that manganese depletion has on S. sanguinis had never been evaluated and a secondary manganese transporter has not been identified. Thus, we employed the use of a fermentor to control large-scale growth over time and depleted manganese in an ΔssaACB mutant using a metal chelator, EDTA. The changes in …


Examination Of Strain-Dependent Differences In S. Sanguinis Virulence And Growth, Shannon Baker Jan 2019

Examination Of Strain-Dependent Differences In S. Sanguinis Virulence And Growth, Shannon Baker

Theses and Dissertations

Streptococcus sanguinis, an abundant and benign inhabitant of the oral cavity, is an important etiologic agent of infective endocarditis, particularly in people with pre-disposing cardiac valvular damage. Although commonly isolated from patients with IE, little is known about the factors that make any particular S. sanguinis isolate more virulent than another or, indeed, whether significant differences in virulence exist among isolates. To investigate the virulence of multiple isolates, a variation of the Bar-seq (barcode sequencing) method was employed. A conserved chromosomal site was identified for subsequent insertion of a barcode identifier, unique for each strain. Barcode insertion did not …


Type Ix Secretion System : Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru Dec 2017

Type Ix Secretion System : Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru

Electronic Theses and Dissertations

Porphyromonas gingivalis and Tannerella forsythia are two of the primary pathogens that are associated in the etiology and progression of chronic periodontitis. In T. forsythia, KLIKK proteases are the recently identified group of proteolytic enzymes that are secreted through Type IX secretion system (T9SS). Among, these KLIKK proteases a synergistic relationship was observed between karilysin and mirolysin in invading the host complement system for the survival of the bacteria. Since, karilysin has been already characterized, in this study we propose to study about mirolysin through structural, biochemical and biological characterization. The obtained results from the experiments has shown the …


Identification Of Transcription Factors Gzf3, Rfx1, Orf19.3928 As Being Implicated In Candida-Bacterial Interactions., Joni Watson May 2015

Identification Of Transcription Factors Gzf3, Rfx1, Orf19.3928 As Being Implicated In Candida-Bacterial Interactions., Joni Watson

Undergraduate Honors Theses

Candida albicans is an opportunistic pathogen that is present in the normal flora in a majority of individuals. One key factor in C. albicans virulence is the ability to change its morphology from yeast to an elongated or hyphal form. The regulation of this morphogenesis relies in part upon quorum sensing (QS) molecules. C. albicans often exists as part of a mixed culture alongside other microbes and is influenced by their presence as well as the presence of QS molecules that they produce. In this study, a library of diploid homozygous transcriptional regulator knockout (TRKO) mutants were screened to identify …


Immunologic Mechanisms Involved With Human Endodontic Lesions, Sunita V. Prabhu Jun 1988

Immunologic Mechanisms Involved With Human Endodontic Lesions, Sunita V. Prabhu

Loma Linda University Electronic Theses, Dissertations & Projects

Endodontic or root canal infection results in immunologic changes in periapical region, which causes the destruction of pulpal and periapical tissue. No definitive study has identified a specific organism or a group of organisms as a etiological agents. Past studies have indicated that immunoglobulin E play a significant role in the pathogenesis of periapical lesions. The presence of this factor suggests that some of the endodontic flare-ups may be IgE-mediated hypersensitivity reactions. Antibody levels of IgA have been quantitatively measured by ELISA and IgE by modified RAST assay, against eleven oral bacteria which are routinely isolated from such lesions. The …