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Full-Text Articles in Life Sciences

Study Of A Putative Niche Adapting Operon In Microbes Inhabiting The Gut Of Blood Digesting Animals, Marlene Abouaassi Aug 2020

Study Of A Putative Niche Adapting Operon In Microbes Inhabiting The Gut Of Blood Digesting Animals, Marlene Abouaassi

Honors Scholar Theses

The sialic acid utilization (SAU) operon is a horizontally acquired gene set that allows bacteria to utilize sialic acid as an alternate source of carbon and nitrogen in the guts of blood eating animals. Sialic acid often occurs as a terminal sugar in complex glycoproteins. It functions in cell signaling and adhesion. Sialic acid is an important component of the cellular envelope of animals. Some microorganisms have evolved to decorate their own surface with sialic acid to evade the host’s immune response (molecular mimicry). The SAU operon encodes enzymes that hydrolyze sialic acid from glycoproteins, transport sialic acid into the …


Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein Jun 2020

Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein

Honors Scholar Theses

In recent years, ciprofloxacin resistant (CpR) Aeromonas veronii and A. hydrophila strains have been isolated from the wounds of patients receiving leech therapy. Genome comparisons of these CpR isolates revealed the presence of chromosomal mutations in gyrA and parC as well as the gain of qnrS2 on either a large, 34 kb, conjugatable, low-copy plasmid, pAv42, or on a small, 6.8 kb, high-copy plasmid, pAh1471. The minimum inhibitory concentration, MIC, for Cp of these clinical isolates ranged from 1 to ≥32 µg/mL and some harbored a qnrS2 containing plasmid. We wanted to assess the contributions of these factors in an …


3,4-Dihydroxyphenylacetate 2,3-Dioxygenase Modulates The Ability Of Enterobacter Hormaechei To Induce Cryptococcus Neoformans Melanization, Amy Nelson Jun 2020

3,4-Dihydroxyphenylacetate 2,3-Dioxygenase Modulates The Ability Of Enterobacter Hormaechei To Induce Cryptococcus Neoformans Melanization, Amy Nelson

Honors Scholar Theses

In this study, we performed transposon mutagenesis to create a library of Enterobacter hormaechei mutants and developed a melanization assay to identify mutants that could not induce the typical melanization phenotype in Cryptococcus neoformans. Relevant phenotype labels included: “hypomelanizer”, a total lack of melanization; “hypermelanizer”, an increased melanization; or “abnormal”, an increased melanization with complete color change of the assay plate to a reddish-brown. Genomic sequencing of 47 mutants and bioinformatic analysis allowed us to pinpoint the transposon insertion site in each E. hormaechei mutant to identify the genes that were affected. A single mutant that induced the abnormal …


Tyrr Regulates The Ability Of Enterobacter Hormaechei To Induce Melanin Production In Cryptoccus Neoformans, Ally Watson May 2020

Tyrr Regulates The Ability Of Enterobacter Hormaechei To Induce Melanin Production In Cryptoccus Neoformans, Ally Watson

Honors Scholar Theses

The yeast Cryptococcus neoformans is present in the microbiota of many plants and animals and produces melanin, a compound that protects cells against UV light and promotes virulence. Melanin production can be induced by exogenous tyrosine, homogentisic acid, catecholamines, or their precursors such as L-DOPA, all of which may be produced by bacteria. The goal of this study was to investigate the interaction between Enterobacter hormaechei (a mosquito gut isolate) and C. neoformans with respect to the production of melanin by C. neoformans in the presence of E. hormaechei, potentially due to the production of L-DOPA or other metabolites …


Rapid Antibiotic Susceptibility Testing Platform For Direct Clinical Samples, Terrance Zhang May 2020

Rapid Antibiotic Susceptibility Testing Platform For Direct Clinical Samples, Terrance Zhang

Honors Scholar Theses

Infectious diseases and septicemia are two of the major causes of death in the U.S., necessitating rapid treatment of septic patients with proper, efficacious antibiotics. Unfortunately, the emergence and spread of multidrug-resistant bacteria are continuously being aggravated by an abuse in antibiotic prescription at a clinical and agricultural level. It is known that antibiotic resistance evolves through the sequential accumulation of multiple mutations in bacteria, which is accentuated by prolonged exposure of bacteria to ineffective antibiotics when implementing traditional septicemia treatment. The goal of this project is to develop a novel, easy-to-use AST platform for rapid antimicrobial susceptibility profiling to …


Identification And Analysis Of Feather Degrading Bacteria: A Search For Keratinase Genes, Nehal Navali May 2020

Identification And Analysis Of Feather Degrading Bacteria: A Search For Keratinase Genes, Nehal Navali

Honors Scholar Theses

Over two million tons of feather waste is generated annually by the poultry industry, the majority of which goes into landfills due to the difficulty of degrading its major component keratin. Although a portion of feather waste is eliminated via incineration or chemical treatment, the use of Feather Degrading Bacteria (FDB) has been proposed as a cheap and eco-friendly alternative. FDBs have been consistently isolated from the feather microbiome of birds and contain genes coding for the specialized protein keratinase which is able to degrade feathers. By doing so, feather waste, which is rich in nutrients, can be repurposed as …


Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro May 2020

Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro

Honors Scholar Theses

Cancer is a disease that stems from genomic errors that are not corrected properly by cellular repair mechanisms. Errors are more likely to form when organisms are subjected to DNA damage by mutagenic compounds. 1-Nitropyrene, a nitrated polycyclic aromatic hydrocarbon (nitro-PAH), has been shown to be a potent mutagen that causes cancer. Nitro-PAHs can arise from diesel exhaust products in the environment. Out of all nitro-PAHs, 1-nitropyrene is found in largest quantities in the environment. This poses a great need to study its effects biochemically in order to address its toxicity in DNA. Other nitropyrene derivatives, including 1,6-dinitropyrene and 1,8-dinitropyrene, …