Bacteria Commons^™

Nutritional Virulence Of Legionella Pneumophila., Ashley M. Best

Electronic Theses and Dissertations

Legionella pneumophila is an environment organism that parasitizes a wide range of protozoa. Growth within the environmental host primes L. pneumophila for infection of human alveolar macrophages when contaminated aerosols are inhaled. Intracellular replication within either host requires the establishment a replicative niche, known as the Legionella-containing vacuole (LCV). Biogenesis of the LCV depends on the type IVb translocation system, the Dot/Icm, to translocation >320 effectors into the host cytosol. Effectors are responsible for preventing lysosome fusion to the LCV, recruitment of ER-derived vesicles to the LCV, and modulation of a plethora of host processes to promote the intracellular …

Infections Not Fought: Antibiotic Resistance In Underserved Communities, Derek Lillestolen

Senior Honors Theses

In 1928, the profound effects of penicillin were discovered and antibiotic treatments became extremely popular. Broad-spectrum antibiotics, like tetracyclines, have been since branded as cure-all prescriptions and used profusely in the Western World and abroad. Due to ignorance of specific biochemical mechanisms and the misuse of antibiotics these drugs inadvertently allowed the rise in prevalence of antibiotic resistant strains of certain bacteria as the century progressed. Now, the specific genetic causes and mechanisms of antibiotic resistance are being understood, but the fight against antimicrobial resistance is far from over. In the United States, thousands of fatalities are caused annually by …

Ketogenic Diet Enhances Neurovascular Function With Altered Gut Microbiome In Young Healthy Mice, David Ma, Amy C. Wang, Ishita Parikh, Stefan J. Green, Jared D. Hoffman, George Chlipala, M. Paul Murphy, Brent S. Sokola, Björn Bauer, Anika M. S. Hartz, Ai-Ling Lin

Sanders-Brown Center on Aging Faculty Publications

Neurovascular integrity, including cerebral blood flow (CBF) and blood-brain barrier (BBB) function, plays a major role in determining cognitive capability. Recent studies suggest that neurovascular integrity could be regulated by the gut microbiome. The purpose of the study was to identify if ketogenic diet (KD) intervention would alter gut microbiome and enhance neurovascular functions, and thus reduce risk for neurodegeneration in young healthy mice (12–14 weeks old). Here we show that with 16 weeks of KD, mice had significant increases in CBF and P-glycoprotein transports on BBB to facilitate clearance of amyloid-beta, a hallmark of Alzheimer’s disease (AD). These neurovascular …

Use Of Urine Antigen Testing For Blastomyces In An Integrated Health System, Dennis J. Baumgardner

Journal of Patient-Centered Research and Reviews

Purpose: Blastomycosis, an endemic fungal infection, mimics many other diseases. We explored the use of Blastomyces urine antigen (BuAg), reportedly the most sensitive noninvasive test, in clinical practice and compared it to other noninvasive tests.

Methods: A total of 836 BuAg tests performed on unique patients (first test only) at one large integrated health system from June 2013 to May 2016 were retrospectively reviewed to examine test characteristics and demographic features. Of these, 100 cases from 2015, a year containing a large local blastomycosis outbreak, were randomly selected for detailed analysis.

Results: Demographics for the BuAg-tested population: mean age 54.9 …

In Vivo Structures Of The Helicobacter Pylori Cag Type Iv Secretion System, Yi-Wei Chang, Carrie L. Shaffer, Lee A. Rettberg, Debnath Ghosal, Grant J. Jensen

Veterinary Science Faculty Publications

The type IV secretion system (T4SS) is a versatile nanomachine that translocates diverse effector molecules between microbes and into eukaryotic cells. Here, using electron cryotomography, we reveal the molecular architecture of the Helicobacter pylori cag T4SS. Although most components are unique to H. pylori, the cag T4SS exhibits remarkable architectural similarity to other T4SSs. Our images revealed that, when H. pylori encounters host cells, the bacterium elaborates membranous tubes perforated by lateral ports. Sub-tomogram averaging of the cag T4SS machinery revealed periplasmic densities associated with the outer membrane, a central stalk, and peripheral wing-like densities. Additionally, we resolved pilus-like …

Pantoea Agglomerans Bacteremia: A Rare Case Of Spontaneous Human Infection By A Plant Pathogen In An Immunocompromised Host., Utsab R. Panta, James A. Joslyn, Rupal D. Shah

Appalachian Student Research Forum

Introduction:

Pantoea agglomerans is a Gram negative ubiquitous bacteria commonly isolated from plant surfaces, seeds, fruits and animal/human feces usually introduced to human by ingestion of infected fruits/vegetables, thorn pricks and gastrointestinal translocation in lack of stomach acidity. However, the pathogen can also cause opportunistic human infection especially when the immune system is impaired. The aim of this case report is to investigate clinical features in a patient with P. agglomerans bacteremia and bring attention the opportunistic infection by this rare bacteria.

Case presentation:

We present a case of 57 year old caucasian lady with past medical history …

Characterization Of The Interaction Between R. Conorii And Human Host Vitronectin In Rickettsial Pathogenesis, Abigail Inez Fish

LSU Doctoral Dissertations

Spotted Fever Group Rickettsia are inoculated into the mammalian host during hematophagous arthropod feeding. Once in the bloodstream and during dissemination, the survival of these pathogens is dependent upon their ability to evade innate host defenses until a proper cellular target is reached. The establishment of a successful infection also relies on the ability of the bacteria to attach and invade target cells, as failure to do so results in destruction of the bacterium. Rickettsia conorii expresses an outer membrane protein, Adr1, which binds the multifunctional human glycoprotein, vitronectin, to promote resistance to complement mediated killing. Homologs of Adr1 are …

In Vitro Assay Development As An Alternative To The Use Of Laboratory Animals For Measuring Clostridium Perfingens Type C Toxoid, Lauren M. Wilmes

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Clostridium perfringens type C produces beta toxin, which is a primary virulence determinate that can cause necrotic enteritis in neonatal animals. Vaccines directed against C. perfringens toxins have shown to be efficacious in preventing disease. However, the production of a commercial vaccine requires not only an efficacious antigen, but also testing methods for quantifying antigens and potency on final product. This research was undertaken to fulfill a need for the reduction in small animal usage to produce and deliver vaccines. The current testing methods are performed in vivo according to the Code of Federal Regulations number 9 (9CFR) United …

Genetic And Molecular Mechanisms Underlying Symbiotic Specificity In Legume-Rhizobium Interactions, Qi Wang, Jinge Liu, Hongyan Zhu

Plant and Soil Sciences Faculty Publications

Legumes are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia. The result of this symbiosis is to form nodules on the plant root, within which the bacteria can convert atmospheric nitrogen into ammonia that can be used by the plant. Establishment of a successful symbiosis requires the two symbiotic partners to be compatible with each other throughout the process of symbiotic development. However, incompatibility frequently occurs, such that a bacterial strain is unable to nodulate a particular host plant or forms nodules that are incapable of fixing nitrogen. Genetic and molecular mechanisms that regulate symbiotic specificity …

Comparative Analysis Of Microbial Sensing Molecules In Mucosal Tissues With Aging, Octavio A. Gonzalez, Sreenatha S. Kirakodu, Michael John Novak, A. J. Stromberg, L. Orraca, J. Gonzalez-Martinez, A. Burgos, Jeffrey L. Ebersole

Center for Oral Health Research Faculty Publications

Host-bacterial interactions at mucosal surfaces require recognition of the bacteria by host cells enabling targeted responses to maintain tissue homeostasis. It is now well recognized that an array of host-derived pattern recognition receptors (PRRs), both cell-bound and soluble, are critical to innate immune engagement of microbes via microbial-associated molecular patterns (MAMP). This report describes the use of a nonhuman primate model to evaluate changes in the expression of these sensing molecules related to aging in healthy gingival tissues. Macaca mulatta aged 3-24 years were evaluated clinically and gingival tissues obtained, RNA isolated and microarray analysis conducted for gene expression of …

Mrub_1199 & Mrub_2272 Of Meiothermus Ruber Are Orthologous Genes To The B0262 Gene In Escherichia Coli While Mrub_1200, Mrub_1201, Mrub_2015 & Mrub_2271 Are Not Orthologous To The B0262 Gene Coding For The Iron (Fe3+) Abc Transport System, Kumail Hussain, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

In this project we investigated the biological function of the genes Mrub_1199, Mrub_1200, Mrub_1201, Mrub_2015, Mrub_2271 and Mrub_2272 (KEGG map number 02010). We predict these genes encode components of an Iron (Fe3+) ATP Binding Cassette (ABC) transporter: 1) Mrub_1199 (DNA coordinates [1211595-1212572] on the reverse strand) encodes the permease component (aka transmembrane domain); and 2) Mrub_1200 (DNA coordinates [1212612-1214093] on the reverse strand) encodes the ATP-binding domain (aka nucleotide binding domain); and 3) Mrub_1201 (DNA coordinates [1214347-1215309] on the reverse strand) encodes the substrate binding protein (aka the periplasmic component); and Mrub_2015 ( DNA coordinates [2053963-2054949] on the reverse strand) …

Usefulness Of The Captia Syphilis Igg Eia Test Method And Reverse Algorithm For Detection Of Syphilis Infection In A Public Health Setting, Patricia Armour

Theses and Dissertations

Syphilis, a systemic sexually transmitted disease, is on the rise in the US, with infection rates the highest recorded since 1994 according to the CDC. Useful laboratory testing is an important diagnostic tool for determining individual syphilis infection and preventing community-wide disease spread.

The purpose of this study was to determine the usefulness of a specific automated treponemal test method, the Captia^TM Syphilis IgG EIA, and the syphilis reverse algorithm interpretation for detecting syphilis infection among patients seeking care in a public health clinic. The study employed a retrospective, nonexperimental descriptive correlational design with data collected between 2012-2013 from …

The Role Of Pro-Inflammatory Mediators Ifnβ And Prostaglandin E2 In Suppression Of Innate Immunity To Listeria Monocytogenes, Michelle G. Pitts

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

As a foodborne pathogen, Listeria monocytogenes (Lm) encounters many barriers to invasion and dissemination in the host that may change the nature of host response. Lm has been most commonly studied using intravenous (i.v.) inoculation, however, a method that delivers a bolus of bacteria directly to the bloodstream. Thus, little is known about what systemic and local mediators are triggered during the natural course of infection and how these may impact susceptibility. Our laboratory used foodborne transmission of Lm in mice to assess whether the method of transmission and the specific organ microenvironment could affect infection-induced secretion of …

Discovery Of New Antimicrobial Options And Evaluation Of Aminoglycoside Resistance Enzyme-Associated Resistance Epidemic, Selina Y. L. Holbrook

Theses and Dissertations--Pharmacy

The extensive and sometimes incorrect and noncompliant use of various types of antimicrobial agents has accelerated the development of antimicrobial resistance (AMR). In fact, AMR has become one of the greatest global threat to human health in this era. The broad-spectrum antibiotics aminoglycosides (AGs) display excellent potency against most Gram-negative bacteria, mycobacteria, and some Gram-positive bacteria, such as Staphylococcus aureus. The AG antibiotics amikacin, gentamicin, kanamycin, and tobramycin are still commonly prescribed in the U.S.A. for the treatment of serious infections. Unfortunately, bacteria evolve to acquire resistance to AGs via four different mechanisms: i) changing in membrane permeability to …

Synthesis And Biological Evaluation Of Novel Drug Candidates To Address Drug Resistance In Tuberculosis And Fungal Diseases, Huy Ngo

Theses and Dissertations--Pharmacy

Tuberculosis (TB) and fungal infections are two of the most lethal infectious diseases worldwide due to the emergence of drug-resistant Mycobacterium tuberculosis (Mtb) and fungal strains that can resist the most potent antimicrobial drugs currently employed. Due to the rise of these drug resistant strains, effective treatment options for these two infections are limited. This dissertation aims at exploring novel drug scaffolds to help combat drug resistance in TB and fungal infections.

TB caused by the pathogenic Mtb is, alongside with human immunodeficiency virus acquired immunodeficiency virus (HIV), the deadliest infectious disease worldwide with approximately 2-3 billion people …

Comparison Between Listeria Sensu Stricto And Listeria Sensu Lato Strains Identifies Novel Determinants Involved In Infection, Jakob Schardt, Grant Jones, Stefanie Müller-Herbst, Kristina Schauer, Sarah E. F. D'Orazio, Thilo M. Fuchs

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The human pathogen L. monocytogenes and the animal pathogen L. ivanovii, together with four other species isolated from symptom-free animals, form the "Listeria sensu stricto" clade. The members of the second clade, "Listeria sensu lato", are believed to be solely environmental bacteria without the ability to colonize mammalian hosts. To identify novel determinants that contribute to infection by L. monocytogenes, the causative agent of the foodborne disease listeriosis, we performed a genome comparison of the two clades and found 151 candidate genes that are conserved in the Listeria sensu stricto species. Two factors were …

Aging, Inflammation, And Gut Microbiota In Mice, Jody Demeo

Honors Projects

Inflammation and gut microbiota are two areas of study that can be linked to aging in the body. As a person ages, systemic inflammation tends to increase, and changes in microbiota in the gastrointestinal system occur as well.

Reducing Biomass Recalcitrance By Heterologous Expression Of A Bacterial Peroxidase In Tobacco (Nicotiana Benthamiana), Ayalew Ligaba-Osena, Bertrand Hankoua, Kay Dimarco, Robert Pace, Mark Crocker, Jesse Mcatee, Nivedita Nagachar, Ming Tien, Tom L. Richard

Center for Applied Energy Research Faculty and Staff Publications

Commercial scale production of biofuels from lignocellulosic feed stocks has been hampered by the resistance of plant cell walls to enzymatic conversion, primarily owing to lignin. This study investigated whether DypB, the lignin-degrading peroxidase from Rodococcus jostii, depolymerizes lignin and reduces recalcitrance in transgenic tobacco (Nicotiana benthamiana). The protein was targeted to the cytosol or the ER using ER-targeting and retention signal peptides. For each construct, five independent transgenic lines were characterized phenotypically and genotypically. Our findings reveal that expression of DypB in the cytosol and ER does not affect plant development. ER-targeting increased protein accumulation, and …

Type Ix Secretion System: Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru

Electronic Theses and Dissertations

Porphyromonas gingivalis and Tannerella forsythia are two of the primary pathogens that are associated in the etiology and progression of chronic periodontitis. In T. forsythia, KLIKK proteases are the recently identified group of proteolytic enzymes that are secreted through Type IX secretion system (T9SS). Among, these KLIKK proteases a synergistic relationship was observed between karilysin and mirolysin in invading the host complement system for the survival of the bacteria. Since, karilysin has been already characterized, in this study we propose to study about mirolysin through structural, biochemical and biological characterization. The obtained results from the experiments has shown the …

Genetic Signatures For Helicobacter Pylori Strains Of West African Origin, Kennady K. Bullock, Carrie L. Shaffer, Andrew W. Brooks, Ousman Secka, Mark H. Forsyth, Mark S. Mcclain, Timothy L. Cover

Veterinary Science Faculty Publications

Helicobacter pylori is a genetically diverse bacterial species that colonizes the stomach in about half of the human population. Most persons colonized by H. pylori remain asymptomatic, but the presence of this organism is a risk factor for gastric cancer. Multiple populations and subpopulations of H. pylori with distinct geographic distributions are recognized. Genetic differences among these populations might be a factor underlying geographic variation in gastric cancer incidence. Relatively little is known about the genomic features of African H. pylori strains compared to other populations of strains. In this study, we first analyzed the genomes of …