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Microbiology

2020

Honors Scholar Theses

Microbiology

Articles 1 - 3 of 3

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 …