Pathogenic Microbiology Commons^™

Infection Potential Of Rickettsia Felis Via Ingestion, Matthew M. Schexnayder

LSU Master's Theses

Rickettsia felis is the etiologic agent of flea-borne spotted fever (FBSF) in humans and a poorly described cause of fever in animals. It is transmitted by its primary arthropod vector and reservoir host, the cat flea Ctenocephalides felis. Known routes of Rickettsia felis transmission between Rickettsia felis-infected cat fleas and vertebrate hosts include cutaneous bites and contamination of cutaneous wounds with infective flea feces. The bulk of FBSF infections occur in young children in Africa, though infections of people at all ages all over the world have been confirmed. As mammals and young children frequently come into contact …

A High Throughput Assay For The Detection Of Stimulator Of Interferon Genes (Sting) Agonists, Michael J. Ingling

Graduate School of Biomedical Sciences Theses and Dissertations

The innate immune system includes a menagerie of different cell types, each with a different role in the process of monitoring the body for invaders and presenting gathered debris (antigen) to the adaptive immune system. Somatic cells have intracellular receptors for the same purpose. Cancer cells, however, have avoided these methods of detection despite, in many cases, the tumor’s immunogenic traits. Immuno-oncology is a field dedicated to the immunological traits of tumors, more recently finding ways of instigating an immune response against tumors. In this regard, STING, a receptor of cyclic dinucleotides (CDN), has come to the forefront of immuno-oncology. …

Molecular Detection Of Pathogenic Leptospira Throughout The Caribbean, Zamara R. Garcia Truitt

Biology Theses

Leptospirosis is a common widespread zoonotic disease found throughout the Caribbean. The infection is produced by a pathogenic Leptospira species found in tropical and subtropical regions. The severity of the disease ranges from a mild asymptomatic infection to death. Leptospirosis is a neglected tropical disease due to the lack of public awareness and health approaches. Therefore, misdiagnosis is common because the symptoms are similar to that of other tropical endemic diseases. The aim of the study was to determine the presence of pathogenic Leptospira in water samples collected from Puerto Rico and Trinidad. Sixty-four environmental water samples were collected throughout …

A Rapid Viability And Drug‑Susceptibility Assay Utilizing Mycobacteriophage As An Indicator Of Drug Susceptibilities Of Anti‑Tb Drugs Against Mycobacterium Smegmatis Mc2 155, Gillian Catherine Crowley, Jim O'Mahony, Aidan Coffey, Riona G. Sayers, Paul D. Cotter

Department of Biological Sciences Publications

Background: A rapid in-house TM4 mycobacteriophage-based assay, to identify multidrug resistance against various anti-tuberculosis drugs, using the fast-growing Mycobacterium smegmatis mc² 155 in a microtiter plate format was evaluated, based on phage viability assays. Methods: A variety of parameters were optimized before the study including the minimum incubation time for the drugs, phage and M. smegmatis mc² 155 to be in contact. An increase in phage numbers over 2 h was indicative that M. smegmatis mc² 155 is resistant to the drugs under investigation, however when phage numbers remained static, M. smegmatis mc² 155 found to …

The Effect Of Intracellular Zinc Levels In Escherichia Coli On Metallo-Β-Lactamase Activity, Jill Thompson

Graduate School of Biomedical Sciences Theses and Dissertations

Antibiotic resistance is a consequence of evolution via natural selection and poses a serious threat to the world's population. Escherichia coli, and other bacterial species, have acquired genes encoding Metallo-β-Lactamases (MBLs). MBLs are zinc-dependent enzymes that degrade most β-lactam antibiotics, and have emerged as important antibacterial resistance determinants in multidrug resistant pathogens. There are several different families of MBLs, and the major clinically relevant ones are Verona Integrated-encoded Metallo-β-Lactamases (VIMs), Imipenemases (IMPs), and New Delhi Metallo-β-Lactamases (NDMs). These enzymes confer high level resistance to penicillins, cephalosporins, and carbapenems, and are not inhibited by FDA-approved β-lactamase inhibitors. Variants of NDM have …

Characterization Of Bacterial Isolates Obtained From Commercial Poultry Feed And Retail Food Using Whole Genome Sequence Analysis And Selected Biochemical Tests, Elena George Olson

Electronic Theses & Dissertations

The goals of this study is two-fold. The first part investigates bacterial isolates from commercial poultry feed and the second part deals with bacterial isolates recovered from retail food. In order to reduce pathogen contamination in poultry products identification of overall microbial populations in poultry production processing steps have always been considered an important monitoring tool for assessing sanitizer effectiveness and the corresponding responses of bacteria load levels on poultry carcasses. Bacterial isolates recovered from corn-based chicken feed were purified on aerobic plate count agar and eleven morphologically different colonies were selected for whole genome sequencing. In this part, the …

Isolation, Analysis, And Partial Characterization Of An Inhibitor Of Neisseria Gonorrhoeae, Natania Paul

Undergraduate Honors Theses

There is an emerging threat of Neisseria gonorrhoeae strains that are resistant to all antibiotics. Because of this, the purpose of this research is to isolate, analyze, and partially characterize a new inhibitor(s) of N. gonorrhoeae. Since there is an unknown molecule secreted by Candida albicans that inhibits N. gonorrhoeae, this molecule can be partially characterized using ¹H NMR Spectroscopy to assist in the development of a new antibiotic compound. It was hypothesized that quorum-sensing molecules, trans, trans- farnesol, tyrosol, phenylethyl alcohol, and tryptophol, could be possible candidates for the inhibitor. Because of this, ¹H …

The Effect Of Stenotrophomonas Maltophilia On Gram-Negative Cystic Fibrosis Pathogens., Joshua D Stewart

College of Arts & Sciences Senior Theses

Cystic Fibrosis (CF) is the most common lethal genetic disorder in the Caucasian population with an incidence of 1 per 3,000 live births and a median predicted survival of only 47 years. Respiratory failure due to repeated pathological insults to lung tissue by infection is the ultimate cause of mortality in the majority of patients. The lung microenvironment created by CF highly favors colonization by opportunistic pathogens such as Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Burkholderia cenocepacia, and Achromobacter xylosoxidans. Biofilm formation by multiple bacterial species contributes to the chronic, persistent, and difficult to treat nature of CF infections. This study seeks …

Reporting Charcoal Rot In Chia And Developing A Susceptibility Assay, Reis M. Misaka, Hagop S. Atamian Dr., Julien Besnard Dr.

Student Scholar Symposium Abstracts and Posters

Chia (Salvia Hispanica) cross breeds were planted in the summer of 2018 with the intent of selective breeding for agricultural benefit. Preexisting pathogens in the soil caused 40-50% fatality of adult plants. This was surprising due to the precursory knowledge that chia has antibiotic and antifungal oils (Elshafie et. al. 2018); chia was only recently documented to be susceptible to Fusarium wilt (Fusarium oxysporum). The primary pathogen responsible was identified as Macrophomina phaseolina (aka charcoal rot); a widespread soilborne pathogen which has multiple commercial hosts (Su et. al. 2001).

M. phaesolina on wheat seed vector where used as …

Iron-Containing Nanoparticles For The Treatment Of Chrionic Biofilm Infections In Cystic Fibrosis, Leisha M. A. Martin

Nanoscience and Microsystems ETDs

Cystic fibrosis (CF) is the most common genetic disease resulting in the morbidity and mortality of Caucasian children and adults worldwide. Due to a genetic mutation resulting in malfunction of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, CF patients produce highly viscous mucus in their respiratory tract. This leads to impairment of the mucociliary clearance of inhaled microbes. In addition to reduced microbial clearance, anoxic environmental conditions in the lungs promote biofilm-mode growth of the pathogenic bacterial species Pseudomonas aeruginosa. Chronic infections of P. aeruginosa begin in early childhood and typically persist until respiratory failure and death result. The …

Lipoarabinomannan From Mycobacterium Smegmatis Stimulates An Inflammatory Response In Raw 264.7 Murine Macrophages, Aysha Zaman

Student Scholar Showcase

Macrophages are a key leukocyte in defense against Mycobacterium tuberculosis infection. The precise mechanism by which M. tuberculosis evades host macrophage defenses remains unknown, so understanding how macrophages interact with cell wall components of mycobacteria is critical. Lipoarabinomannan (LAM) is a glycolipid Toll-like receptor-2 (TLR-2) ligand found on the cell wall of mycobacteria, and is thought to contribute to the cell wall structural integrity. When LAM binds to TLR on host leukocytes, this activates cellular responses and phagocytosis by host macrophages. Nitric oxide production can be used as a measure of inflammatory response and can be evaluated via nitrite response …

Combating Drug Resistance - Comparison Of The Antibiotic Effect Of Hydrastis Canadensis Extract And Pure Berberine Via Minimum Inhibitory Concentration Assay, William Luke Scott, Timothy D. Trott

Research in Biology

Herbal medicines are a melee of complex organic chemicals, making it difficult to ascertain their direct mechanism of action. In contrast to mainstream pharmaceuticals, it is argued that herbal medicines are effective because of multiple constituents working synergistically. The complexity of herbal medicines may give them advantages over simpler pharmaceuticals in combating antibiotic resistant microbes, but these advantages can be difficult to quantitate. Popular literature frequently espouses the healing properties of herbal medicines, but many of these claims are not scientifically supported. Many gains could be realized in public health and medicine if more research was aimed at validating / …

Effectiveness Of Windrow Composting Methodology In Killing A Thermo-Tolerant Species Of Salmonella During Mortality Composting, Spencer Gabriel Myers

Master's Theses

In a large agricultural operation, such as the one at Cal Poly San Luis Obispo, disposal of deceased animals is an immense issue. The cost of transporting and rendering every dead animal is inhibitory to the general function of the agricultural operations and their thin budget. Therefore, we propose that composting mortalities could be an economical alternative. Composting is a recognized method for taking animal waste products along with carbon waste and turning it into a pathogen-free, nutrient-rich topsoil. Carcass composting is in fact performed in other countries and states to varying degrees of success. However, the California EPA limits …

The Occurrence Of Listeria Monocytogenes In The Mushroom Production Chain And The Use Of Bacteriophage For Its Control, Vincenzo Pennone

Theses

In Agaricus bisporus production, the occurrence of L. monocytogenes is still poorly understood. A number of studies have shown the presence of L. monocytogenes in the mushroom processing environment, suggesting its source from raw materials storage areas (Viswanath et al, 2013; Murugesan et al, 2015). In this study, 10 mushroom producers and three raw material (compost and casing) producers participated in two surveys on the occurrence of L. monocytogenes in the most high-risk areas of the production environment. In the first survey, floors, drains, platforms, crates, raw materials and mushrooms were tested for L. monocytogenes presence and the results were …

High Resolution Modeling Of Tick Density And Detection Of Rickettsia Spp. In Dermacentor Spp. Ticks At Turnbull National Wildlife Refuge, Wa, Justin L. Donahue

EWU Masters Thesis Collection

The tick species Dermacentor andersoni and Dermacentor variabilis are known vectors of pathogens. One such pathogen is the bacteria Rickettsia rickettsii, which causes Rocky Mountain spotted fever. The detection of this bacterium in ticks at Turnbull National Wildlife Refuge (TNWR) indicates a potential risk to human health. In order to follow up on this discovery, we had two separate objectives. First we developed a high resolution predictive map for Dermacentor spp. distribution across the public use area of TNWR. To do so, 50m transects (27 in total) were established across the public use area. Ticks were collected weekly within the …

Improved Methods For The Quantification Of Viable Ascaris Suum And Application To Biosolids, Tanner Keyzers

Dissertations, Master's Theses and Master's Reports

The current method for detection of Ascaris ova in biosolids and wastewater has several drawbacks including being labor and time intensive as well as being difficult to quantify viable ova that have larvated during treatment. The goal of this thesis was to improve several methods for the detection and quantification of Ascaris ova during long term-storage of biosolids including improvement of quantifying viable ova using a heat and bleach treatment to promote movement of larvae inside of ova, and comparison of the traditional microscopic method with qPCR and PMA-qPCR to prevent the false-positive results. Improved methods to promote movement of …

Crystallographic Structure Determination Of Bacteriophage-Encoded Enzymes That Specifically Target Pathogenic Bacteria, Marta Sanz Gaitero

Theses

Antibiotic resistance is becoming a serious public health concern. Infections that some decades ago could be treated with antibiotics now sometimes do not respond to traditional treatment, causing higher mortality and economic losses. An alternative to the use of antibiotics are bacteria's natural predators, bacteriophages (or phages), and specifically their lytic enzymes. These proteins are produced by phages to degrade bacterial peptidoglycan to inject their genetic material into the bacteria (virion-associated peptidoglycan hydrolases) or to release their progeny once the infection is finished (endolysins). They can be applied exogenously to lyse Gram-positive bacteria or be genetically engineered to lyse Gram-negative …

The Role Of Cody In Hydrogen Peroxide Tolerance And Biofilm Formation Of Streptococcus Mutans, Kaitlin M. Rioux, Brandaliz Santiago-Narvaez

Honors Program Theses

Streptococcus mutans is the major cariogenic bacterium in the oral cavity. S. mutans causes disease by three main virulence factors: acid production, acid tolerance, and biofilm formation. S. mutans outcompetes various other species in the oral cavity, however it is affected by hydrogen peroxide production by these species. Based on previous findings and this research, hydrogen peroxide is shown to extend the lag phase of S. mutans but does not kill it unless present in extremely high amounts that are generally not produced by commensal species like S. sanguinis and S. gordonii in the oral cavity. CodY is a global …

The Microbiomes Of Pancreatic And Duodenum Tissue Overlap And Are Highly Subject Specific But Differ Between Pancreatic Cancer And Non-Cancer Subjects, Erika Del Castillo, Richard Meier, Mei Chung, Devin C. Koestler, Tsute Chen, Bruce J. Paster, Kevin P. Charpentier, Karl T. Kelsey, Jacques Izard, Dominique S. Michaud

Department of Food Science and Technology: Faculty Publications

Background: In mice, bacteria from the mouth can translocate to the pancreas and impact pancreatic cancer progression. In humans, oral bacteria associated with periodontal disease have been linked to pancreatic cancer risk. It is not known if DNA bacterial profiles in the pancreas and duodenum are similar within individuals.

Methods: Tissue samples were obtained from 50 subjects with pancreatic cancer or other conditions requiring foregut surgery at the Rhode Island Hospital (RIH), and from thirty-four organs obtained from the National Disease Research Interchange. 16S rRNA gene sequencing was performed on 189 tissue samples (pancreatic duct, duodenum, pancreas), 57 …

Illumination Of The Golgi Apparatus Of Pathogenic And Nonpathogenic Naegleria Species, Tyler M. Poe

Theses and Dissertations

In this study, Naegleria fowleri, a pathogenic amoeba and the causative agent of Primary Amebic Meningoencephalitis (PAM), was utilized to determine the presence or absence of classically conserved Golgi molecules featured in the expression of a Golgi apparatus. Previous studies concluded no Golgi expression via light microscopy and transmission electron microscopy, but a recent report on Naegleria gruberi indicated the presence of dispersed Golgi tubules. Non-pathogenic species of the Naegleria genus such as Naegleria gruberi 30540 and Naegleria lovaniensis 30569 were utilized in Western immunoblot analysis compared to reduced whole-cell lysate proteins of two strains of N. fowleri and …