Other Microbiology Commons^™

The Stringent Response In Pseudomonas Aeruginosa Influences The Phenotypes Controlled By The Gac/Rsm System, Michael Shawn Hooker

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a ubiquitous, opportunistic pathogen that causes acute and chronic infections. Infection is typically initiated via motile and virulent strains. After exposure to stressors, acute infections make both genotypic and phenotypic switches to a chronic, sessile strain. This is due to intricate regulatory networks directing gene expression in response to stressors. One network, GacA/GacS, has been established to control virulence factors. The stringent response of bacteria is mediated by alarmones produced primarily by RelA which responds to starvation.

To study the effect of the stringent response on the virulence switch. A series of experiments were run in both …

Understanding The Adhesion Mechanism In Mycelium-Assisted Wood Bonding, Wenjing Sun

Electronic Theses and Dissertations

The increasing environmental awareness has led to an increased interest in developing more sustainable materials as alternatives to petroleum-derived products. Among different nature-based products, fungal-mycelium-based bio-composites have gained considerable attention in various applications. Multiple materials with different densities and structures and potential applications can be fabricated by inoculating filamentous white-rot fungi in lignocellulosic materials and other substrates. Different from lower-density as-grown foam-like mycelium composites, higher-density mycelium-lignocellulosic panels have the potential to replace commercial particleboard and fiberboard bonded by petroleum-based resins. This kind of composite can be produced by directly adding heat and pressure to the low-density foams or by assembling …

Identification Of “Fhua” Like Genes In Rhizobium Leguminosarum Atcc 14479 And Its Role In Vicibactin Transport And Investigation Of Heme Bound Iron Uptake System, Sushant Khanal

Electronic Theses and Dissertations

Siderophores are low molecular weight, iron chelating compounds produced by many bacteria for uptake of iron in case of iron scarcity. Vicibactin is a trihydroxamate type siderophore produced by Rhizobium leguminosarum bv. trifolii ATCC 14479. This work focuses on identifying an outer membrane receptor involved in the transport of vicibactin. We have confirmed the presence of the putative fhuA gene in R. leguminosarum bv. trifolii ATCC 14479. This bacteria shows mutualistic symbiosis with the red clover plant Trifoliium prantense. Leghemoglobin, with its cofactor heme is present in the plant root nodules that surrounds the infecting organism present in the nodules. …

Candida And Pseudomonas Interact To Enhance Mucosal Infection In Transparent Zebrafish, Audrey C. Bergeron

Electronic Theses and Dissertations

Polymicrobial communities exist throughout the human body and include both fungi and bacteria. During disease, cross-kingdom interactions among bacteria, fungi, and/or the immune system can alter virulence and lead to complex polymicrobial infections. The fungus C. albicans is among the most commonly isolated fungi in the context of fungal-bacterial co-infections and is often accompanied by the bacterium P. aeruginosa at a variety of sites throughout the body including mucosal tissues such as the lung. In vitro, C. albicans and P. aeruginosa have a cyclic, bi-directional, and largely antagonistic relationship, but these interactions do not account for the role of the …

Effects Of Lactobacillus Rhamnosus Milk Isolate On The Production Of Inflammatory Cytokines In Enterocytes, Beverly C. Ngeny

Electronic Theses and Dissertations

In the gastrointestinal tract, probiotics have been shown to promote host immunity and to regulate immune signaling pathways. This study used Caco-2 cell line to examine the effects of a Lactobacillus rhamnosus isolate from “amabere amaruranu” a Kenyan traditional cultured milk, on the production inflammatory cytokines in enterocytes. Live Lactobacillus rhamnosus (MRS6AN), its cytoplasmic fraction (CF), filtered spent broth (FSB) or heat inactivated FSB (HIB) were used as treatments on differentiated Caco-2 cell monolayer in transwells. Cytokine content in the cell lysates, apical and basolateral supernatants were determined using ELISA. Caco-2 cell lysate treatments showed significantly increased anti-inflammatory TGF-β (ng/ml) …

Influence Of Lactobacillus Rhamnosus Isolated From “Amabere Amaruranu” Cultured Milk On Adipogenesis, Justin E. Kotala

Electronic Theses and Dissertations

This study was performed to test the in vitro effects of a Lactobacillus rhamnosus isolate from “amabere amaruranu”, a traditional Kenyan cultured milk, on 3T3-L1 and Caco-2 cell lines. Cultures of fully mature 3T3-L1 adipocytes were treated with bacterial isolate cell extract (CE), filtered spent broth (FSB) from overnight bacterial culture, or with a PBS control. Expression levels of PPAR³1 and 2, C/EBP±, and ATGL proteins in 3T3-L1 cells were upregulated by FSB treatment. CE treatment did not affect protein expression levels. Expression of MTTP and SREBP-1c proteins in Caco-2 cells showed no change with either treatment. Optical density measurements …

Identification Of Genes Required To Synthesize An Antibiotic-Like Compound From The Soil Bacterium Rhodococcus Sp. Mtm3w5.2, Amber L. Ward

Electronic Theses and Dissertations

Rhodococcus is a soil bacterium, member of the Actinobacteria, and a close relative of the prolific small molecule producer Streptomyces. Recent interest in Rhodococcus as an under investigated source of possible bioactive secondary metabolites is sparked by the discovery of many polyketide synthase and non-ribosomal peptide synthetase genes of unknown function from sequenced Rhodococcus genomes. Rhodococcus species strain MTM3W5.2 was recently shown to produce a strong inhibitory compound with activity against most strains of Rhodococcus and closely related genera. A goal of this investigation is to discover the gene(s) required to synthesize this inhibitory molecule. The engineered Rhodococcus …

Detection Of Bacterial Retroelements Using Genomics, Sen Mu

Electronic Theses and Dissertations

The reverse flow of genetic information can occur when a special DNA polymerase called Reverse Transcriptase (RT) copies the genetic information in an RNA molecule back into a complementary DNA. One type of RT encoding gene found in bacteria is called a retron element. Recent bacterial genome sequencing projects have revealed many examples of retron RT genes. This gene assignment is based on comparison with a few known retron RT proteins. However, RT proteins are highly diverse in their amino acid sequences, and thus the assigned identity of these RT proteins as retrons in genome databases is questionable. One way …