Life Sciences Commons^™

The Essential Role Of Carbon Metabolism In The Virulence Of Cryptococcus Neoformans, Mara Weigner

Senior Honors Theses

Cryptococcus neoformans infections are a major cause of meningoencephalitis in immunosuppressed patients worldwide. Inhaled as spores or desiccated yeast cells, C. neoformans can undergo metabolic changes in response to the new host environment that allow it to cross the blood brain barrier and cause deadly central nervous system (CNS) infections. Nutrient acquisition, and specifically carbon metabolism, is critical for survival and proliferation within the host. Notably, efficient carbon metabolism is necessary to produce the polysaccharide capsule, which is arguably C. neoformans’ most important and well-studied virulence factor. As such, a better understanding of carbon acquisition and regulation is essential for …

Glycan Precursor Transport In Cryptococcus Neoformans, Lucy X. Li

Arts & Sciences Electronic Theses and Dissertations

Glycans play diverse biological roles, ranging from structural and regulatory functions to mediating cellular interactions. For pathogens, they are also often required for virulence and survival in the host. Our interest in glycoconjugates stems from their role in the fungal pathogen Cryptococcus neoformans. This yeast colonizes the lungs and disseminates to the brain of immunocompromised individuals, where it causes a meningoencephalitis that is frequently lethal, killing almost 200,000 people each year. The major virulence factor of this yeast is a polysaccharide capsule that enables it to manipulate the host immune response and resist host antimicrobial defenses.

Synthesis of the capsular …

Halogen Bonding And Host–Guest Chemistry Between N-Alkylammonium Resorcinarene Halides, Diiodoperfluorobutane And Neutral Guests, Fangfang Pan, Mohadeseh Dashti, Michael R. Reynolds, Kari Rissanen, John F. Trant, Ngong Kodiah Beyeh

Chemistry and Biochemistry Publications

Single crystal X-ray structures of halogen-bonded assemblies formed between host N-hexylammonium resorcinarene bromide (1) or N-cyclohexylammonium resorcinarene chloride (2), and 1,4-diiodooctafluorobutane and accompanying small solvent guests (meth- anol, acetonitrile and water) are presented. The guests’ inclusion affects the geometry of the cavity of the receptors 1 and 2, while the divalent halogen bond donor 1,4-diiodooctafluorobutane determines the overall nature of the halogen bond assembly. The crystal lattice of 1 contains two structurally different dimeric assemblies A and B, formally resulting in the mixture of a capsular dimer and a dimeric pseudo-capsule. ¹H …

Determining Key Residues Of The Lyt-R Domain In The Streptococcal Cpsa Protein, Mohammad Hashmi

Honors College

Streptococcus agalactiae or Group B Streptococcus (GBS), is a Gram-positive commensal bacterium that is harmless in healthy adults, yet causes systemic diseases in neonates, the elderly, and immunocompromised individuals. Neonates are at risk of GBS infection in utero or during delivery due to the colonization of the organism in the vaginal canal of between 15-30% of adult females. GBS can cause severe neonatal sepsis and meningitis, as well as chorioamnionitis, which can cause premature birth and stillbirth. GBS infection is greatly facilitated by the presence of a bacterial capsule; a protective, polysaccharide matrix surrounding the cell that plays a key …

Determining The Key Residues For Capsule Production In The Gbs Cpsa Protein, Anna Struba

Honors College

Streptococcus agalactiae (GBS) is a common bacterium found commensally in the vaginal mucosa of healthy adults. GBS also causes severe infection in neonates, often leading to meningitis, which can cause lifelong health consequences including impaired hearing and seizures. Infection of newborns mainly arises from a colonized mother, either before birth through ascending infection or during labor. Ascending infection, where the bacteria travel to the fetus from the vaginal mucosa, is especially concerning as it can lead to loss of pregnancy or premature birth. The most common method of neonatal GBS disease prevention is antibiotic prophylaxis during delivery, though this method …