Biology Commons^™

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 …

Characterizing The Diversity Of The Eukaryotic Microbiome In Marine Crustacean Zooplankton., Rose-Lynne Savage

Electronic Thesis and Dissertation Repository

Understanding zooplankton productivity is critical for modeling marine food web function, of which one poorly known factor is the influence of zooplankton symbionts. Zooplankton protist symbiont diversity is underestimated due to the limited surveys and techniques previously used. Using 18S V4 metabarcoding, I characterized the eukaryotic microbiomes associated with crustacean zooplankton from the northern Strait of Georgia, BC. Apostome ciliates were most abundant in all hosts except for cyclopoid copepods, which were dominated by Syndiniales. Most symbiont lineages were more abundant in one or two hosts, suggesting some degree of host preference. Microbiome data also provided information on diet, confirming …

Genetic Population Structure And Microbiome Of German Cockroaches In Urban Environments, Xueyang Fan

Dissertations

Pests of human habitats may harbor and disperse pathogens that cause human disease. One such pest is the German cockroach (Blattella germanica), which is known to harbor numerous pathogens, including Klebsiella and Pseudomonas. The aim of this study is to reveal the importance of the German cockroach as a potential vector of human medically important diseases. To do so, this study investigates German cockroach population structure and their associated bacterial microbiome in urban residential environments. Ninety German cockroaches are collected from three residential apartment buildings in three New Jersey cities. Samples are caught by glue traps and stored at -20°C. …

The Roles Of Host Species, Geographic Scale And Environmental Stressors In Shaping The Composition Of Coral Microbiomes, Alicia Marie Riegel Parker

LSU Doctoral Dissertations

Reef-building corals are long-lived and may take many centuries to adapt, making them especially susceptible to climate change. However, corals host microbial symbionts that can change quickly, potentially speeding acclimation. My dissertation aimed to determine the degree of coevolution and flexibility between corals and their microbiomes among hosts, across space, and in response to stress.

Microbial communities are usually surveyed by sequencing the 16S rRNA gene, however the PCR primers used also amplify coral DNA, thereby limiting prokaryotic read coverage. To mitigate this contamination, I designed a peptide nucleic acid clamp that increased the recovery of bacterial reads by 2-11x …

The Effects Of An Applied Phyllosphere-Microbiome On Gas Exchange And Growth Of Soybean Infected With Pseudomonas Syringae: Harnessing The Power Of The Microbiome, Charles Agbavor

MSU Graduate Theses

The microbiome is an important determinant of plant health, growth and resistance to stress. This study was conducted to determine the efficacy of the phyllosphere-microbiome on managing Pseudomonas syringae pv. Glycinea (Psg), gas exchange and growth of Glycine max L. Merrill. A greenhouse study was conducted in the summer of 2019. A field isolated and cultured soybean phyllosphere-microbiome was applied to purposely infected and uninfected soybean. Gas exchange, Psg density, chlorophyll concentrations, and percent nitrogen and carbon in the leaves were measured during the V3-V6 stages of soybean. Not surprisingly, there was a two-fold reduction in copies of Pseudomonas …

Accessing The Functional Capabilities Of The Tick Microbiome Through Metagenomics, Darin Lee Shrewsberry Jr

Graduate Theses, Dissertations, and Problem Reports

The black-legged tick Ixodes scapularis is a common ectoparasite of animals and an obligate blood feeder, attaching to a host animal and taking a blood meal once per life stage (i.e. 3 times during its life). Unfortunately for the tick, blood represents a nutrient poor diet largely consisting of lipids and proteins but notably lacking in essential nutrients such a B vitamins (e.g., biotin, riboflavin, niacin) Other exclusive blood feeders such as the tsetse fly harbor symbiotic bacteria that provision B-complex vitamins to their host. I. scapularis harbors Rickettsia buchneri an endoparasitic bacterium that intriguingly possesses two copies of a …