Medicine and Health Sciences Commons^™

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 …

Defining Electron Bifurcation In The Electron-Transferring Flavoprotein Family, Amaya M. Garcia Costas, Saroj Poudel, Anne-Frances Miller, Gerrit J. Schut, Rhesa N. Ledbetter, Kathryn R. Fixen, Lance C. Seefeldt, Michael W. W. Adams, Caroline S. Harwood, Eric S. Boyd, John W. Peters

Chemistry Faculty Publications

Electron bifurcation is the coupling of exergonic and endergonic redox reactions to simultaneously generate (or utilize) low- and high-potential electrons. It is the third recognized form of energy conservation in biology and was recently described for select electron-transferring flavoproteins (Etfs). Etfs are flavin-containing heterodimers best known for donating electrons derived from fatty acid and amino acid oxidation to an electron transfer respiratory chain via Etf-quinone oxidoreductase. Canonical examples contain a flavin adenine dinucleotide (FAD) that is involved in electron transfer, as well as a non-redox-active AMP. However, Etfs demonstrated to bifurcate electrons contain a second FAD in place of the …

Comparative Study On The In Vitro Effects Of Pseudomonas Aeruginosa And Seaweed Alginates On Human Gut Microbiota, Shaofeng Bai, Huahai Chen, Liying Zhu, Wei Liu, Hongwei Yu, Xin Wang, Yeshi Yin

Hongwei Yu

Alginates pertain to organic polysaccharides that have been extensively used in food- and medicine-related industries. The present study obtained alginates from an alginate overproducing Pseudomonas aeruginosa PAO1 mutant by screening transposon mutagenesis libraries. The interaction between bacterial and seaweed alginates and gut microbiota were further studied by using an in vitro batch fermentation system. Thin-layer chromatography (TLC) analysis indicated that both bacterial and seaweed alginates can be completely degraded by fecal bacteria isolated from study volunteers, indicating that a minor structural difference between bacterial and seaweed alginates (O-acetylation and lack of G-G blocks) didn’t affect the digestion of alginates by …

The Oral Microbiome And Adverse Pregnancy Outcomes., Charles M. Cobb, Patricia J. Kelly, Karen B. Williams, Shilpa Babbar, Mubashir Angolkar, Richard J. Derman

Department of Obstetrics and Gynecology Faculty Papers

Significant evidence supports an association between periodontal pathogenic bacteria and preterm birth and preeclampsia. The virulence properties assigned to specific oral pathogenic bacteria, for example, Fusobacterium nucleatum, Porphyromonas gingivalis, Filifactor alocis, Campylobacter rectus, and others, render them as potential collaborators in adverse outcomes of pregnancy. Several pathways have been suggested for this association: 1) hematogenous spread (bacteremia) of periodontal pathogens; 2) hematogenous spread of multiple mediators of inflammation that are generated by the host and/or fetal immune response to pathogenic bacteria; and 3) the possibility of oral microbial pathogen transmission, with subsequent colonization, in the vaginal microbiome resulting from sexual …

A Platform For The Discovery And Characterization Of Proteins That Associate With Pseudomonas Aeruginosa Rna Polymerase, Danielle N. Brogren

All NMU Master's Theses

Pseudomonas aeruginosa is an opportunistic bacterial pathogen notable for its ability to colonize the lungs of cystic fibrosis patients. Once the bacterium infects and colonizes humans, it is extremely difficult to eradicate. This leads to long-term infections that significantly damage the lungs and other tissues. P. aeruginosa infections are challenging to treat due to the bacterium’s natural antibiotic resistance and the rise of multidrug resistant strains. Development of novel drug treatments are a necessity.

In all organisms, the regulation of gene expression is a highly controlled process. Remarkably, in P. aeruginosa bioinformatics studies showed that 20% of its genome is …

Burkholderia Pseudomallei Enters The Brain And Spinal Cord Via The Trigeminal Nerve, Heidi Walkden, James St John, Lynn Nazareth, Jenny Ekberg

Jenny Ekberg

Background

The trigeminal nerve is the largest cranial nerve responsible for sensation in the face and motor functions such as chewing. It constitutes a direct route from the nasal cavity into the brain (Fig. 1). Despite this, only a handful of microorganisms are thought to infect the brain via this route.

The tropical disease melioidosis caused by Burkholderia pseudomallei is endemic to the northern Australia and south-east Asia. The main route of transmission is via inhalation of droplets and soil. The Australian variant can result in brain infection, but the mechanism of infection is unknown.

Here, we investigated whether …

Microbial Extracellular Polymeric Substances (Epss) In Ocean Systems, Alan W. Decho, Tony Gutierrez

Faculty Publications

Microbial cells (i.e., bacteria, archaea, microeukaryotes) in oceans secrete a diverse array of large molecules, collectively called extracellular polymeric substances (EPSs) or simply exopolymers. These secretions facilitate attachment to surfaces that lead to the formation of structured ‘biofilm’ communities. In open-water environments, they also lead to formation of organic colloids, and larger aggregations of cells, called ‘marine snow.’ Secretion of EPS is now recognized as a fundamental microbial adaptation, occurring under many environmental conditions, and one that influences many ocean processes. This relatively recent realization has revolutionized our understanding of microbial impacts on ocean systems. EPS …

Comparison Of The Sensitivity Of Biomarker Based Matrix Assisted Laser Desorption Ionization-Time Of Flight Mass Spectrometry (Maldi-Tof Ms) And Conventional Methods In The Identification Of Clinically Relevant Bacteria And Yeast, Ali Abdow Kassim

Theses & Dissertations

Background: MALDI-TOF MS is an analytical method that has recently become integral in the identification of microorganisms in clinical laboratories. It relies on databases that majorly employ pattern recognition or fingerprinting. Biomarker based databases have also been developed and there is optimism that these may be superior to pattern recognition based databases. This study compared the performance of ribosomal biomarker based MALDI-TOF MS and conventional methods in the identification of selected bacteria and yeast.

Methodology: The study was a cross sectional study carried out in collaboration with the Swiss Tropical and Public Health Institute, Switzerland and Mabritec laboratory, Riehen, Switzerland. …

The Effect Of Bundled Interventions On Prevention Of Hospital Acquired Clostridium Difficile Infection, Kaitlin Kendys

Evidence-Based Practice Project Reports

Clostridium difficile infection (CDI) rates have steadily increased in hospitalized patients due to the change in epidemiology. Approximately 13 of every 1,000 inpatients are either infected or colonized with C. difficile (CDC, 2013). CDI rates continue to rise due to the hyper-virulent strain of C. difficile and length of therapy needed to treat CDI. The average cost for a single inpatient CDI is more than $35,000, and the estimated annual cost burden for the healthcare system exceeds $3 billion (Walsh, 2012). The purpose of this evidence-based project (EBP) was to reduce hospital-acquired CDI rates over a 3-month period-oftime from November …

The Effect Of Staphylococcus Aureus On Stiffness Of Cortical Bone, Ariel N. Kunde

Graduate Theses

Osteomyelitis, a term for bone infection, is a common cause of hospitalization in the United States. Infection leading to osteomyelitis is almost always a product of bacterial origin. Although polymicrobial presence is seen at infection sites of osteomyelitis, Staphylococcus aureus is most commonly isolated and found to be the cause of more than 95% of bone infection in adults. This organism is a common commensal of humans that is carried by an estimated 60% of the US population. S. aureus is transferred by infected asymptomatic individuals, and its ability to proliferate under a variety of environmental conditions contributes to the …

Enhancement Of Reactive Oxygen Species Production And Chlamydial Infection By The Mitochondrial Nod-Like Family Member Nlrx1, Ali A. Abdul-Sater, Najwene Saïd-Sadier, Verissa M. Lam, Bhavni Singh, Matthew A. Pettengill, Fraser Soares, Ivan Tattoli, Simone Lipinski, Stephen E. Girardin, Philip Rosenstiel, David M. Ojcius

David M. Ojcius

Chlamydia trachomatis infections cause severe and irreversible damage that can lead to infertility and blindness in both males and females. Following infection of epithelial cells, Chlamydia induces production of reactive oxygen species (ROS). Unconventionally, Chlamydiae use ROS to their advantage by activating caspase-1, which contributes to chlamydial growth. NLRX1, a member of the Nod-like receptor family that translocates to the mitochondria, can augment ROS production from the mitochondria following Shigella flexneri infections. However, in general, ROS can also be produced by membrane-bound NADPH oxidases. Given the importance of ROS-induced caspase-1 activation in growth of the chlamydial vacuole, we investigated the …

The New Penicillin?, Nikki Huynh

EGS Content

Clostridium difficile infects and kills 30,000-40,000 people a year in the United States. In order to target and minimize the spread of C. difficile we are screening puupehenone, a natural marine product that is excreted from some species of sponges and coral as a defense mechanism, and repurposing its role for medical use. Our research primarily focuses on determining puupehenone’s antimicrobial properties. This was determined by testing the minimum inhibitory concentration (MIC) of puupehenone as it relates to a single strain of C. difficile, and then observing whether the antimicrobial properties hold across multiple strains of the bacterium. The strain …

The New Penicillin?, Nikki Huynh

Nikki Huynh

Haemophilus Influenzae Type B Invasive Disease In Amish Children, Missouri, Usa, 2014, Angela L. Myers, Mary Anne Jackson, Lixin Zhang, Douglas S. Swanson, Janet R. Gilsdorf

Manuscripts, Articles, Book Chapters and Other Papers

© 2017, Centers for Disease Control and Prevention (CDC). All rights reserved. During 5 months in 2014, three Amish children in Missouri, USA, were diagnosed with invasive Haemophilus influenzae type b infection. Two were rural neighbors infected with a genetically similar rare strain, sequence type 45. One child had recently traveled, raising the possibility of maintenance of this strain among unvaccinated carriers in Amish communities.

Comparative Study On The In Vitro Effects Of Pseudomonas Aeruginosa And Seaweed Alginates On Human Gut Microbiota, Shaofeng Bai, Huahai Chen, Liying Zhu, Wei Liu, Hongwei Yu, Xin Wang, Yeshi Yin

Biochemistry and Microbiology

Alginates pertain to organic polysaccharides that have been extensively used in food- and medicine-related industries. The present study obtained alginates from an alginate overproducing Pseudomonas aeruginosa PAO1 mutant by screening transposon mutagenesis libraries. The interaction between bacterial and seaweed alginates and gut microbiota were further studied by using an in vitro batch fermentation system. Thin-layer chromatography (TLC) analysis indicated that both bacterial and seaweed alginates can be completely degraded by fecal bacteria isolated from study volunteers, indicating that a minor structural difference between bacterial and seaweed alginates (O-acetylation and lack of G-G blocks) didn’t affect the digestion of alginates by …

Dual-Functional-Tag-Facilitated Protein Labeling And Immobilization, Xinyi Zhang, Wei Lu, Kevin Kwan, Dibakar Bhattacharyya, Yinan Wei

Chemistry Faculty Publications

An important strategy in the construction of biomimetic membranes and devices is to use natural proteins as the functional components for incorporation in a polymeric or nanocomposite matrix. Toward this goal, an important step is to immobilize proteins with high efficiency and precision without disrupting the protein function. Here, we developed a dual-functional tag containing histidine and the non-natural amino acid azidohomoalanine (AHA). AHA is metabolically incorporated into the protein, taking advantage of the Met-tRNA and Met-tRNA synthetase. Histidine in the tag can facilitate metal-affinity purification, whereas AHA can react with an alkyne-functionalized probe or surface via well-established click chemistry. …

The Fatty Acid Regulator Fadr Influences The Expression Of The Virulence Cascade In The El Tor Biotype Of Vibrio Cholerae By Modulating The Levels Of Toxt Via Two Different Mechanisms, Gabriela Kovacikova, Wei Lin, Ronald K. Taylor, Karen Skorupski

Dartmouth Scholarship

FadR is a master regulator of fatty acid (FA) metabolism that coordinates the pathways of FA degradation and biosynthesis in enteric bacteria. We show here that a ΔfadR mutation in the El Tor biotype of Vibrio cholerae prevents the expression of the virulence cascade by influencing both the transcription and the posttranslational regulation of the master virulence regulator ToxT. FadR is a transcriptional regulator that represses the expression of genes involved in FA degradation, activates the expression of genes involved in unsaturated FA (UFA) biosynthesis, and also activates the expression of two operons involved in saturated FA (SFA) biosynthesis. …

Bis(N-Amidinohydrazones) And N-(Amidino)-N'-Aryl-Bishydrazones: New Classes Of Antibacterial/Antifungal Agents, Sanjib K. Shrestha, Liliia M. Kril, Keith D. Green, Stefan Kwiatkowski, Vitaliy M. Sviripa, Justin Robert Nickell, Linda Phyliss Dwoskin, David S. Watt, Sylvie Garneau-Tsodikova

Pharmaceutical Sciences Faculty Publications

The emergence of multidrug-resistant bacterial and fungal strains poses a threat to human health that requires the design and synthesis of new classes of antimicr obial agents. We evaluated bis(N-amidinohydrazones) and N-(amidino)-N'-aryl-bishydrazones for their antibacterial and antifungal activities against panels of Gram-positive/Gram-negative bacteria as well as fungi. We investigated their potential to develop resistance against both bacteria and fungi by a multi-step, resistance-selection method, explored their potential to induce the production of reactive oxygen species, and assessed their toxicity. In summary, we found that these compounds exhibited broad-spectrum antibacterial and antifungal activities against most of …

Role Of Intracellular Growth During The Gastrointestinal Stage Of Listeria Monocytogenes Infection, Grant Steven Jones

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

Listeria monocytogenes is a facultative intracellular bacterium that causes foodborne disease in humans. L. monocytogenes invade the gut mucosa and then disseminate, causing systemic infections associated with high mortality rates in immunocompromised individuals. It is unknown how L. monocytogenes traffic to the mesenteric lymph nodes, which represent an important bottleneck for systemic spread. In addition, little is known about the gastrointestinal stage of infection due to the general resistance of mice to oral infection with L. monocytogenes. Our laboratory developed a novel foodborne mouse model of listeriosis utilizing a murinized strain of L. monocytogenes to investigate the gastrointestinal stage …