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Pathogenic Microbiology Commons

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University of Massachusetts Amherst

Articles 1 - 8 of 8

Full-Text Articles in Pathogenic Microbiology

Nascent Dna Proteomics Analysis Uncovers Dna Replication Dynamics In The Human Pathogen Trypanosoma Brucei, Maria Rocha Granados Jan 2019

Nascent Dna Proteomics Analysis Uncovers Dna Replication Dynamics In The Human Pathogen Trypanosoma Brucei, Maria Rocha Granados

Doctoral Dissertations

DNA is the substrate of many cellular processes including DNA replication, transcription and chromatin remodeling. These processes are coordinated to maintain genome integrity and ensure accurate duplication of genetic and epigenetic information. Genome-wide studies have provided evidence of the relationship between transcription and DNA replication timing. A global analysis of DNA replication initiation in T. brucei showed that TbORC1 (subunit of the origin recognition complex, ORC) binding sites are located at the boundaries of transcription units. Although recent studies in T. brucei indicate functional links among DNA replication and transcription, the underlying mechanisms remain unknown. In this study, we adapted ...


The Role Of The Metallochaperone Hypa In The Acid Survival And Activities Of Nickel Enzymes In Helicobacter Pylori, Heidi Hu Jan 2018

The Role Of The Metallochaperone Hypa In The Acid Survival And Activities Of Nickel Enzymes In Helicobacter Pylori, Heidi Hu

Doctoral Dissertations

Helicobacter pylori is a bacterium that has colonized the human gastric mucosa of over 50% of the world population. Persistent infection can cause gastritis, peptic ulcers, and cancers. The ability of H. pylori to colonize the acidic environment of the human stomach is dependent on the activity of the nickel containing enzymes, urease and NiFe-hydrogenase. The nickel metallochaperone, HypA, was previously shown to be required for the full activity of both enzymes. In addition to a Ni-binding site, HypA also contains a structural Zn site, which has been characterized to alter its averaged structure depending on pH and the presence ...


Trypanosoma Brucei Mitochondrial Dna Polib Cell Cycle Localization And Effect On Polic When Polib Is Depleted, Sylvia L. Rivera Jan 2016

Trypanosoma Brucei Mitochondrial Dna Polib Cell Cycle Localization And Effect On Polic When Polib Is Depleted, Sylvia L. Rivera

Masters Theses

Trypanosoma brucei is the causative agent of Human African Trypanosomiasis (HAT), also known as African sleeping sickness. T. brucei is unique in several ways that distinguish this organism from other eukaryotes. One of the unique features of T. brucei is the organism’s mitochondrial DNA, which is organized in a complex structure called kinetoplast DNA (kDNA). Since kDNA is unique to the kinetoplastids, kDNA may serve as a good drug target against T. brucei. Previews studies have shown that kDNA has 4 different family A mitochondrial DNA polymerases. Three of these mitochondrial DNA polymerases (POLIB, POLIC, and POLID) are essential ...


Distribution Of Enterotoxigenic Clostridium Perfringens Spores In U.S. Retail Spices, Chi-An Lee Jan 2016

Distribution Of Enterotoxigenic Clostridium Perfringens Spores In U.S. Retail Spices, Chi-An Lee

Masters Theses

246 samples of bulk and packaged spices from retail stores in the western, southeastern, southern, midwestern, and northeastern areas of the U.S. were examined for the presence of Clostridium -perfringens. Isolates were checked for the presence of the lecithinase gene (cpa) and enterotoxin genes (cpe) by PCR. Enterotoxin formation during sporulation was investigated using the Oxoid Toxin Detection Kit. Forty-three confirmed isolates (from 17% of total samples) were cpa-positive. Of those, 27 were cpe-positive. Together, levels of C. perfringens spores ranged from 3.6-2400/gm. The amount of enterotoxin in cell extracts ranged from 2-16 ng/ml ...


Novel Advancements For Improving Sprout Safety, Kyle S. Landry Jan 2016

Novel Advancements For Improving Sprout Safety, Kyle S. Landry

Doctoral Dissertations

All varieties of bean sprouts (mung bean, alfalfa, broccoli, and radish) are classified as a “super-food” and are common staples for health conscious consumers. Along with the proposed health benefits, there is also an inherent risk of foodborne illness. When sprouts are cooked, there is little risk of illness. The purpose of this dissertation was to explore novel techniques to minimize or prevent the incidence of foodborne illness associated with the consumption of sprouts. Three areas were investigated: 1) the use of a biocontrol organism, 2) the use of a novel spontaneous carvacrol nanoemulsion, and 3) the influence of the ...


Eneterotoxigenic Bacillus Cereus And Bacillus Thuringiensis Spores In U.S. Retail Spices, Upasana Hariram Jan 2015

Eneterotoxigenic Bacillus Cereus And Bacillus Thuringiensis Spores In U.S. Retail Spices, Upasana Hariram

Masters Theses

Bacillus cereus is a ubiquitous organism and a potential foodborne pathogen that can cause two types of gastrointestinal diseases: emesis and diarrhea. The emetic syndrome is caused by a heat and acid stable peptide toxin that is pre-formed in food, while the diarrheal syndrome is associated to two 3-protein, heat labile enterotoxin complexes that are formed in the intestine after ingestion of the organism. There are many reports on the isolation and characterization of Bacillus cereus from various foods, however there are no studies on the levels, toxigenicity and physical characteristics of B. cereus isolated from U.S. retail spices ...


Mitochondrial Dna Polymerase Ib: Functional Characterization Of A Putative Drug Target For African Sleeping Sickness, David F. Bruhn May 2011

Mitochondrial Dna Polymerase Ib: Functional Characterization Of A Putative Drug Target For African Sleeping Sickness, David F. Bruhn

Open Access Dissertations

Trypanosoma brucei and related parasites are causative agents of severe diseases that affect global health and economy. T. brucei is responsible for sleeping sickness in humans (African trypanosomiasis) and a wasting disease in livestock. More than 100 years after T. brucei was identified as the etiological agent for sleeping sickness, available treatments remain inadequate, complicated by toxicity, lengthy and expensive administration regiments, and drug-resistance. There is clear need for the development of a new antitrypanosomal drugs. Due to the unique evolutionary position of these early diverging eukaryotes, trypanosomes posses a number of biological properties unparalleled in other organisms, including humans ...


A Multidisciplinary Approach To Food Safety Evaluation: Hummus Spoilage And Microbial Analysis Of Kitchen Surfaces In Residential Child Care Institutions (Rcci) In Massachusetts, U.S.A., Elsina E. Hagan Jan 2011

A Multidisciplinary Approach To Food Safety Evaluation: Hummus Spoilage And Microbial Analysis Of Kitchen Surfaces In Residential Child Care Institutions (Rcci) In Massachusetts, U.S.A., Elsina E. Hagan

Masters Theses 1911 - February 2014

Food borne illnesses continues to be a public health challenge in the United States (U.S.); an estimated 9.4 million incident cases occurred in 2011. In view of this challenge we conducted two food safety studies; 1) related to product formulation (hummus spoilage challenge study) and 2) evaluating the microbial safety of domestic kitchen surfaces in Residential Child Care Institutions (RCCI pilot study).

Hummus is of Mediterranean origin but is currently eaten globally. This challenge study evaluates a variety of industrial hummus formulations (four in total, differing in pH and/or addition of a preservative (natamycin). Two batches were ...