Microbiology Commons^™

Exploring The Niche Of Rickettsia Montanensis (Rickettsiales: Rickettsiaceae) Infection Of The American Dog Tick (Acari: Ixodidae), Using Multiple Species Distribution Model Approaches, Catherine A. Lippi, Holly Gaff, Alexis L. White, Heidi K. St. John, Allen L. Richards, Sadie J. Ryan

Biological Sciences Faculty Publications

The American dog tick, Dermacentor variabilis (Say) (Acari: Ixodidae), is a vector for several human diseasecausing pathogens such as tularemia, Rocky Mountain spotted fever, and the understudied spotted fever group rickettsiae (SFGR) infection caused by Rickettsia montanensis. It is important for public health planning and intervention to understand the distribution of this tick and pathogen encounter risk. Risk is often described in terms of vector distribution, but greatest risk may be concentrated where more vectors are positive for a given pathogen. When assessing species distributions, the choice of modeling framework and spatial layers used to make predictions are important. …

Assessment Of Grain Safety In Developing Nations, Jose R. Mendoza

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Grains are the most widely consumed foods worldwide, with maize (Zea mays) being frequently consumed in developing countries where it feeds approximately 900 million people under the poverty line of 2 USD per day. While grain handling practices are acceptable in most developed nations, many developing nations still face challenges such as inadequate field management, drying, and storage. Faulty grain handling along with unavoidably humid climates result in recurrent fungal growth and spoilage, which compromises both the end-quality and safety of the harvest. This becomes particularly problematic where there is little awareness about health risks associated with poor …

Structural Characterization Of Two Large Icosahedral Dna Viruses And Their Capsid Assembly Mechanisms, Yuejiao Xian

Open Access Theses & Dissertations

In the last three decades, many large DNA viruses were discovered and grouped into a loosely defined clade of Nucleocytoplasmic Large DNA Viruses (NCLDVs). NCLDVs infect a wide range of hosts from single cellular protists to large animals. Recently, these viruses were classified as a new phylum of Nucleocytoviricota under the kingdom of Bamfordvirae. The genomes of these Nucleocytoviricota viruses (NCVs) are remarkedly large and complicated, containing many cellular genes from all three domains of life, which raised intensive debates on their evolutionary origins. Despite being classified in the same phylum, their physical structures vary and can be roughly classified …

Molecular Detection Of Host-Specific Fecal Bacteria In Three Major Watersheds Of Piedmont Georgia, Muhammad Amar

Biology Theses

Abstract

Fecal pollution is a major concern in creeks and rivers. The aim of this study was to enumerate fecal coliform bacteria and identify the source of contamination using Microbial Source Tracking at three different creeks (Mountain Oak, Long Cane, and Ulcohatchee) in the Piedmont region of Georgia. Data collected in this research will be used to formulate watershed rehabilitation plans to decrease the transfer of fecal indicator bacteria (FIB) into these creeks. Samples were collected at several sites along the creeks (4 sites at Mountain Oak, 10 sites at Long Cane, and 5 sites at Ulcohatchee). The site locations …

Malaria, Microbes, And Mice: The Role Of The Gut Microbiota On The Immune Response To Plasmodium Infection And The Treatment Potential Of Microbiota Modulation., Morgan L. Waide

Electronic Theses and Dissertations

Plasmodium infection leads to over 200 million cases of malaria and 400,000 deaths worldwide each year. These deaths are largely in children under the age of five and pregnant women [1]. Caused by transmission of Plasmodium parasites by the female Anopheles mosquito, malaria poses a risk for over 40 percent of the world’s population [1]. Despite worldwide efforts to eradicate malaria leading to a decrease in malaria-associated mortalities in the early 2000s [2], growing resistance to the available antimalarials and the lack of an effective, long-lasting vaccine has caused this decrease to plateau in recent years [1, 3-6]. Furthermore, malaria …

A Pharmacological Strategy Against African Sleeping Sickness, Wahaj Zuberi

Dissertations and Theses (Open Access)

Trypanosoma brucei is a parasitic eukaryote and is the causal agent of the disease known as African sleeping sickness, transmitted via the bite of a tsetse fly. If left untreated, the parasite ultimately crosses the blood-brain eventually leading to death. Currently there are 5 approved drugs used to treat it, each with toxic side effects and effective at specific disease stages. A more effective and less toxic drug candidate is highly sought after. The essential enzyme, dUTPase, is an excellent drug target in the parasite while utilizing S. cerevisiae as a model system.

dUTPase is essential in T. brucei (tbdUTPase), …

Examining Pathogenesis And Preventatives In Spontaneous And Staphylococcus-Induced Bacterial Chondronecrosis With Osteomyelitis In Broilers, Nnamdi Simon Ekesi

Graduate Theses and Dissertations

Bacterial chondronecrosis with osteomyelitis is the most important cause of lameness in broilers. This is important to poultry production, as it poses animal welfare issues, and causes a significant loss in revenue. The remediation of this disease requires the study of its etiology with fitting models and evaluating preventatives. The research reported herein covers genomic virulence analysis of BCO isolates, mainly Staphylococcus aureus, and Escherichia coli retrieved from lame birds. We found that S. aureus isolates were closest to chicken strains in Europe but may have been in the Arkansas area for a decade. Phylogenomics suggest our S. aureus is …

Optimization Of In-Vessel Food Waste Composting: Enzyme Activity And Microbial Dynamics, Ayawovi Selom Ametepe

Graduate Theses and Dissertations

A series of greenhouse-based, rotary-drum bioreactor experiments was designed to study microbial dynamics and enzyme activity during optimization of food waste composting. This work aims to optimize food waste composting by defining the best food waste-to-bulking agent proportion controlling conditions and by evaluating the food waste composting process when inoculated by a bacterial inoculant product compared to uninoculated compost. Three experiments were run in total. The two first experiments were conducted for 48 days with sampling at each step of composting, while the third experiment last 50 days and included one extra sampling date. In the first experiment, 50:50, 65:35 …

Polerovirus Genomic Variation And Mechanisms Of Silencing Suppression By P0 Protein, Natalie M. Holste

School of Biological Sciences: Dissertations, Theses, and Student Research

The family Luteoviridae consists of three genera: Luteovirus, Enamovirus, and Polerovirus. The genus Polerovirus contains 32 virus species. All are transmitted by aphids and can infect a wide variety of crops from cereals and wheat to cucurbits and peppers. However, little is known about how this wide range of hosts and vectors developed. In poleroviruses, aphid transmission and virion formation is mediated by the coat protein read-through domain (CPRT) while silencing suppression and phloem limitation is mediated by Protein 0 (P0)—a protein unique to poleroviruses. P0 gives poleroviruses a great advantage amongst plant viruses and diversifies polerovirus species, but the …

Mosquito Microbiomes: Understanding The Interface Between Microbiome, Environment, And Human Pathogens, Amanda G. Tokash-Peters

Graduate Doctoral Dissertations

The study of mosquito microbiomes promises a deeper understanding of factors influencing interactions between mosquito hosts, human pathogens, and the environment. While several studies have focused on tripartite interactions between host, pathogen, and microbiome, far fewer have analyzed the environmental factors that shape these interactions and provide the basis for the formation of microbial communities in the mosquito host. Additionally, the use of Wolbachia and similar anti-arboviral symbionts in mosquitoes to control pathogen transmission has emerged as a popular idea for mosquito control and requires further investigation. The works presented here address changes in mosquito microbiomes, including the abundance of …

Investigating The Potential Of Microbial Metabolites And Mtor Signaling On Chicken Necrotic Enteritis, Mohit Bansal

Graduate Theses and Dissertations

Necrotic enteritis (NE), caused by C. perfringens and coccidiosis, is responsible for substantial economic loss annually. In the first chapter, we investigated the effect of secondary bile acid on necrotic enteritis. Day-old broiler chicks were randomly assigned to 5 groups of diets supplemented with 0 (basal diet), 0.8, 1.0, and 1.5 g/kg (on top of basal diet) deoxycholic acid (DCA). The birds were challenged with Eimeria maxima (20,000 oocysts/bird) at d 18 and C. perfringens (109CFU/bird/day) at d 23 and d 24 to induce NE. Birds were sacrificed at d 26, and ileal tissue and digesta samples were collected. DCA …

Effects Of Commercial Feed Additives On Growth Performance And Gut Microbiota Of Nursery Pigs, Xiaoyuan Wei

Graduate Theses and Dissertations

To secure animal welfare and maximum production, feed additives are often added to nursery pig diets to increase nutrition digestibility, enhance intestinal health, and prevent or mitigate disease, with the ultimate goal of improving growth performance. This thesis performed a longitudinal analysis using next-generation sequencing to investigate the dynamic changes of gut microbiota in weaned pigs fed commercial feed additives. Chapter II was used to evaluate the effects of organic acid mixture on growth performance and gut microbiota of weaning pigs. This study demonstrated that the inclusion of 0.035% (SBA0.035) or 0.070% (SBA0.070) sodium butyrate in a diet containing 0.5% …

The Role Of The Msaabcr Operon In Implant-Associated Chronic Osteomyelitis In Staphylococcus Aureus Usa300 Lac, Gyan S. Sahukhal, Michelle Tucci, Hamed Benghuzzi, Gerri Wilson, Mohamed O. Elasri

Faculty Publications

The msaABCR operon regulates several staphylococcal phenotypes such as biofilm formation, capsule production, protease production, pigmentation, antibiotic resistance, and persister cells formation. The msaABCR operon is required for maintaining the cell wall integrity via affecting peptidoglycan cross-linking. The msaABCR operon also plays a role in oxidative stress defense mechanism, which is required to facilitate persistent and recurrent staphylococcal infections. Staphylococcus aureus is the most frequent cause of chronic implant-associated osteomyelitis (OM). The CA-MRSA USA300 strains are predominant in the United States and cause severe infections, including bone and joint infections.

Biogeography Of The Bovine Respiratory Microbiome And Its Relationship With Bovine Respiratory Disease, Jianmin Chai

Graduate Theses and Dissertations

Bovine respiratory disease (BRD) is the most common and costly disease in the beef cattle industry, leading to high morbidity, mortality and huge economic loss. Despite the recent advances in vaccination and antimicrobial techniques, no significant health-improved outcomes have developed. Due to a deep investigation of the microbiome, respiratory microbiotas are known to have important roles for host health and disease. However, BRD specific pathogens have not yet been identified since they are found in both healthy and diseased animals. A systemic and comprehensive study of the biogeography of the bovine respiratory microbiome and its relationship with BRD is lacking …

Comprehensive Survey Of The Litter Bacterial Communities In Commercial Turkey Farms, Bishnu Adhikari, Guillermo Tellez-Isaias, Tieshan Jiang, Brian Wooming, Young Min Kwon

Poultry Science Faculty Publications and Presentations

The importance of microbiota in the health and diseases of farm animals has been well-documented for diverse animal species. However, studies on microbiotas in turkey and turkey farms are relatively limited as compared to other farm animal species. In this study, we performed a comprehensive survey of the litter microbiotas in 5 commercial turkey farms in the Northwest Arkansas (H, M, V, K, and R farms) including one farm with positive incidence of cellulitis (R farm). Altogether 246 boot swabs were used for 16S rRNA gene profiling of bacterial communities. At phylum level, 11 major bacterial phyla (≥0.01%) were recovered. …

Ixodes Scapularis Src Kinase Is Required For Rickettsial Pathogen Survival In Ticks, Jeremy W. Turck

Biological Sciences Theses & Dissertations

Anaplasma phagocytophilum is an obligate intracellular bacterium that causes disease in humans and animals. It is the causative agent for human anaplasmosis. A. phagocytophilum uses certain strategies to infect both vertebrates and invertebrates. It uses Ixodes scapularis ticks as a vector for spreading infection to other mammal species. This bacterium has a specific path for infection through the salivary glands of its vector host. It also suppresses certain functions such as the inhibition of apoptosis and ROS production in order to increase its survival in ticks. Src kinase, a non-receptor protein-tyrosine kinase, is a major player in cell signaling. Src …

Drivers Of Rickettsial Pathogen Transmission And Spillover In Local Tick Populations In Southeastern Virginia, Alexandra Cumbie

Biomedical Sciences Theses & Dissertations

Cases of spotted fever group rickettsiosis are becoming more prevalent in the United States. In Virginia, there are three human-biting ticks which are largely responsible for the spread of rickettsial pathogens and the increase in disease cases. These species include Dermacentor variabilis, Amblyomma americanum, and Amblyomma maculatum; all of which are vectors of rickettsial agents to vertebrate hosts. These species are sympatric as adults and have the potential to share large and small mammal hosts. Their interactions on and off host and their associated rickettsiae were the focus of this dissertation work. Amblyomma americanum is the vector …

Copper And Cobalt Metal Conjugation Enhances Flaviviral Replication, And Denv/Zikv Caused Thrombocytopenia Suppresses Integrin Signaling, Shovan Dutta

Biomedical Sciences Theses & Dissertations

Vector control is a global concern, and effective strategies have been on the way. Among the many different strategies, insect repellents to protect us from blood-feeding arthropods are very common. Food processing or preservatives in food expose us to several chemicals associated with insect repellents, insecticides, and pesticides. Using metallic conjugation with plant extracts or essential oils has become a widespread strategy to increase their efficacy. But it is worth it to be aware that some of those metallic compounds like Cobalt or Copper upon conjugation with thiosemicarbazone ligands derived from Citral and 2-acetylethiazole at the center coordination enhance both …

In The Margins: Reconsidering The Range And Contribution Of Diazotrophs In Nearshore Environments, Corday R. Selden

OES Theses and Dissertations

Dinitrogen (N₂) fixation enables primary production and, consequently, carbon dioxide drawdown in nitrogen (N) limited marine systems, exerting a powerful influence over the coupled carbon and N cycles. Our understanding of the environmental factors regulating its distribution and magnitude are largely based on the range and sensitivity of one genus, Trichodesmium. However, recent work suggests that the niche preferences of distinct diazotrophic (N₂ fixing) clades differ due to their metabolic and ecological diversity, hampering efforts to close the N budget and model N₂ fixation accurately. Here, I explore the range of N₂ fixation …

Acute Ischemic Stroke As The Presenting Feature Of Covid-19 In The Young And Pregnant, Nermila A. Ballmick, Jiri F. Kubac, Hossein Akhondi

HCA Healthcare Journal of Medicine

Introduction: Coronavirus disease (COVID-19) is an emerging and rapidly evolving public health issue that has become globally widespread and an overwhelming pandemic. Clinical manifestations of the disease include asymptomatic carrier states, acute respiratory distress syndrome, and even multiorgan dysfunction. Here, we present a unique and rare case of an acute ischemic stroke (AIS) in an asymptomatic pregnant woman with no predisposing medical illnesses.

Discussion: An 18-year-old G2P1 African American woman at 7 weeks gestational age with no significant medical or family history presenting to the Emergency Department during the initial phases of the pandemic with complaints of new onset left …