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Determining Effects Of Management Practices On Potato Early Dying And Soil Microbiome And Assessing Risk Of Fungicide Resistance In Verticillium Dahliae, Kedi Li Dec 2021

Determining Effects Of Management Practices On Potato Early Dying And Soil Microbiome And Assessing Risk Of Fungicide Resistance In Verticillium Dahliae, Kedi Li

Electronic Theses and Dissertations

Potato early dying (PED) is a yield-constraining soilborne disease of potato, caused by Verticillium spp. with V. dahliae being the predominant causal agent. Since the pathogen inhabits soil for long periods, PED management aims to reduce the population of V. dahliae in soil. Benzovindiflupyr and azoxystrobin are effective chemicals and frequently used in the control of V. dahliae. In this study, field trials were conducted at Aroostook Farm, Presque Isle, ME in 2019 and 2020. Chemical and biological products have been studied for PED control, and fungicide resistance was also examined. To evaluate fungicide resistance, benzovindiflupyr was characterized on …


Retroviral Infection Dynamics In Maine's Wild Turkeys, Stephanie A. Shea Dec 2021

Retroviral Infection Dynamics In Maine's Wild Turkeys, Stephanie A. Shea

Electronic Theses and Dissertations

Widespread wild turkey reintroductions in the late 1900s have led to increases in population density and geographic distribution across North America. This rapid population expansion has put them into proximity with closely-related wild and domestic avian species, increasing the risks of pathogen transmission. Lymphoproliferative disease virus (LPDV) is an avian oncogenic retrovirus detected in wild turkeys in 2009, and previously known to infect domestic turkeys. Following its initial detection, surveys reported variable LPDV prevalence across eastern North America with most wild turkeys being asymptomatic, however diagnostic cases revealed 10% mortality of LPDV-infected individuals. Given its recent detection, little is known …


Impact Of Probiotics On Black Soldier Fly Larvae Transmission Of Stenotrophomonas Maltophilia, Emily Marie Mclaughlin Dec 2021

Impact Of Probiotics On Black Soldier Fly Larvae Transmission Of Stenotrophomonas Maltophilia, Emily Marie Mclaughlin

Honors College

Stenotrophomonas maltophilia is an opportunistic pathogen which can cause a variety of infections, especially in immunocompromised individuals. It has recently been found that black soldier flies can act as carriers for S. maltophilia (Callegari et al., 2020). I have investigated how probiotics impact their vector capabilities. Black soldier fly larvae have been fed substrate spiked with S. maltophilia. After several days of feeding, the larvae were investigated by PCR and plating (Sveensson-Stadler et al., 2011). Two groups of larvae were fed with potatoes infected with S. maltophilia. Persistence of S. maltophilia was determined using PCR by taking samples …


Characterizing The Role Of Prophages On Whib7 Expression And Antibiotic Resistance In Mycobacterium Chelonae, Jaycee J. Cushman Aug 2021

Characterizing The Role Of Prophages On Whib7 Expression And Antibiotic Resistance In Mycobacterium Chelonae, Jaycee J. Cushman

Electronic Theses and Dissertations

Mycobacterial pathogens are responsible for an ongoing public health crisis. Mycobacterium abscessus is the causative agent of lung infections that disproportionately affect immunocompromised individuals and is the most intrinsically antibiotic-resistant bacterial species known. These characteristics make M. abscessus infections difficult to treat, with a success rate of only 45%. While some extensively resistant isolates are caused by mutations in drug targets, others appear to be a result of increased intrinsic drug resistance. Common among these strains is the presence of integrated viral genomes (prophage) that are known to contribute to fitness and antibiotic resistance in other pathogens but whose roles …


Understanding The Adhesion Mechanism In Mycelium-Assisted Wood Bonding, Wenjing Sun Aug 2021

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 …


Deciphering The Perpetual Fight Between Virus And Host: Utilizing Bioinformatics To Elucidate The Host's Genetic Mechanisms That Influence Jc Polyomavirus Infection, Michael P. Wilczek Aug 2021

Deciphering The Perpetual Fight Between Virus And Host: Utilizing Bioinformatics To Elucidate The Host's Genetic Mechanisms That Influence Jc Polyomavirus Infection, Michael P. Wilczek

Electronic Theses and Dissertations

JC polyomavirus (JCPyV) is a human-specific pathogen that infects 50-80% of the population, and can cause a deadly, demyelinating disease, known as progressive multifocal leukoencephalopathy (PML). In most of the population, JCPyV persistently infects the kidneys but during immunosuppression, it can reactivate and spread to the central nervous system (CNS), causing PML. In the CNS, JCPyV targets two cell types, astrocytes, and oligodendrocytes. Due to the hallmark pathology of oligodendrocyte lysis observed in disease, oligodendrocytes were thought to be the main cell type involved during JCPyV infection. However, recent evidence suggests that astrocytes are targeted by the virus and act …


Infection And Diet-Induced Gut Dysbiosis: Impact On Sleep Quality In Danio Rerio, Benjamin Williams May 2021

Infection And Diet-Induced Gut Dysbiosis: Impact On Sleep Quality In Danio Rerio, Benjamin Williams

Honors College

A known bidirectional relationship between intestinal microflora and the central nervous system, coined the gut-brain-axis, has stimulated work on the association between gut dysbiosis and inflammation, and sleep quality. Previous studies in the Hayes Lab have reported that a high fat (HF) diet was correlated with immobile phases, a marker of low motility during sleep found in some neurological disease and sleep duration[1]. Long sleep duration (>1 S.D. above norms for age) is associated with poor sleep quality or sleep fragmentation in participants who are overweight or obese according to body mass index values[2]. The current work utilizes a …


The Role Of Accessory Domain In Cpsa Function And Capsule Production In Group B Streptococcus, Gina Difederico May 2021

The Role Of Accessory Domain In Cpsa Function And Capsule Production In Group B Streptococcus, Gina Difederico

Honors College

Group B Streptococcus (GBS) can be found in the vaginal and genitourinary tract of females, as well as the genitourinary tract of males, where it behaves as a commensal organism. However, as an opportunistic pathogen, GBS has the capability to infect the immunocompromised, making it a major threat to neonates and fetuses. The pathogen can be passed from mother to baby either in utero or during birth. The capsule, which is a polysaccharide coating on the outside of the cell, is considered the most important virulence factor in GBS.Expression of capsule plays a role in evasion of the host immune …


Understanding The Role Of Prophage Encoded Polymorphic Toxins In Mycobacterial Superinfection Immunity And Drug Resistance, Dakota Archambault May 2021

Understanding The Role Of Prophage Encoded Polymorphic Toxins In Mycobacterial Superinfection Immunity And Drug Resistance, Dakota Archambault

Honors College

Mycobacterium abscessusis the leading cause of lung infection in cystic fibrosis patients and is often resistant to all antibiotics. There is an urgent need for alternative therapies such as lytic bacteriophage (viruses that infect bacteria). Phage therapy has been successful in the treatment of a drug-resistantM. abscessusinfection in a teenaged cystic fibrosis patient but there are challenges to broad use as most M. abscessusisolates are highly resistant to lytic bacteriophage infection. Prophage, or integrated bacteriophage genomes within the M. abscessusgenome, likely defend against phage superinfection via prophage-encoded viral defense systems. The Molloy lab has shown that the Mab cluster R …


An Investigation Of The Relationship Between Black Soldier Fly Larvae Pathogen Suppression And Growth Substrate In Relation To Maine Agricultural Industries, Haley Morrill May 2021

An Investigation Of The Relationship Between Black Soldier Fly Larvae Pathogen Suppression And Growth Substrate In Relation To Maine Agricultural Industries, Haley Morrill

Honors College

Insects are promoted as cost-effective and sustainable protein sources for animal feed. Their utilization may help to avoid a predicted global protein shortage. Black soldier fly (Hermetia illucens) larvae (BSFL) grow on organic wastes, converting these wastes into larval biomass which can fulfill this purpose. Potential benefits of using BSFL to remediate organic wastes include reduction of waste mass and bacterial load, along with the sale of larvae as a protein supplement. BSFL suppress the growth of some Gram-positive and Gram-negative human pathogens in these substrates; though suppression of Bacillus cereus, a spore-forming bacterium that causes food-poisoning, …


Characterizing The Diversity Of Cluster R Prophage In Mycobacterium Abscessus, Colin Welch May 2021

Characterizing The Diversity Of Cluster R Prophage In Mycobacterium Abscessus, Colin Welch

Honors College

Mycobacterium abscessus is a mycobacterial pathogen responsible for pulmonary and disseminated infections in susceptible individuals and often is resistant to all antibiotic therapies, with cure rates ranging from 25% to 58% (Degiacomi et al., 2019).Investigating the mechanisms of extensive resistance in M. abscessus lends opportunities to develop more effective treatments. Prophage, viral sequences integrated into bacterial genomes, contribute to virulence and fitness in many bacterial pathogens including Escherichia coli O157:H7 and Vibrio cholerae (Fortier & Sekulovic, 2013). Yet, prophage in pathogenic mycobacteria are not well understood or studied. Recent work has demonstrated that the Mycobacterium chelonae prophage, McProf can function …