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Articles 1 - 30 of 92

Full-Text Articles in Medical Sciences

Gut Microbiota, Blood Metabolites, And Left Ventricular Diastolic Dysfunction In Us Hispanics/Latinos, Kai Luo, Alkis Taryn, Eun-Hye Moon, Brandilyn A Peters, Scott D Solomon, Martha L Daviglus, Mayank M Kansal, Bharat Thyagarajan, Marc D Gellman, Jianwen Cai, Robert D Burk, Rob Knight, Robert C Kaplan, Susan Cheng, Carlos J Rodriguez, Qibin Qi, Bing Yu May 2024

Gut Microbiota, Blood Metabolites, And Left Ventricular Diastolic Dysfunction In Us Hispanics/Latinos, Kai Luo, Alkis Taryn, Eun-Hye Moon, Brandilyn A Peters, Scott D Solomon, Martha L Daviglus, Mayank M Kansal, Bharat Thyagarajan, Marc D Gellman, Jianwen Cai, Robert D Burk, Rob Knight, Robert C Kaplan, Susan Cheng, Carlos J Rodriguez, Qibin Qi, Bing Yu

Journal Articles

BACKGROUND: Left ventricular diastolic dysfunction (LVDD) is an important precursor of heart failure (HF), but little is known about its relationship with gut dysbiosis and microbial-related metabolites. By leveraging the multi-omics data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a study with population at high burden of LVDD, we aimed to characterize gut microbiota associated with LVDD and identify metabolite signatures of gut dysbiosis and incident LVDD.

RESULTS: We included up to 1996 Hispanic/Latino adults (mean age: 59.4 years; 67.1% female) with comprehensive echocardiography assessments, gut microbiome, and blood metabolome data. LVDD was defined through a composite criterion …


Ethanol Leaf Extracts Of Anogeissus Leiocarpus In Antioxidants And Hepatotoxic Effects Of Escherichia Coli Infected Swiss Mice, Fred Coolborn Akharaiyi, Chioma Bertha Ehis-Eriakha, Peter Taiwo Olagbemide, Stephen Eromosele Akemu Feb 2024

Ethanol Leaf Extracts Of Anogeissus Leiocarpus In Antioxidants And Hepatotoxic Effects Of Escherichia Coli Infected Swiss Mice, Fred Coolborn Akharaiyi, Chioma Bertha Ehis-Eriakha, Peter Taiwo Olagbemide, Stephen Eromosele Akemu

BioMedicine

Introduction: Diseases caused by bacteria can be managed with medicinal plants with rightful dosage that will not affect body physiology and organs.

Aim: This research aimed to evaluate the antioxidants and the effects of Anogeisus leiocarpus on liver function.

Materials and Methods: Ethanol leaf extracts were processed for antioxidants and hepatotoxic effects using animal models. Group one (negative control) was given access to water and regular feed, group two (positive control) was dosed with 107 CFU/ml of Escherichia coli O157:H7, and groups 3-6 were dosed with 107 E. coli O157:H7 for 3 days and treated with extract concentrations of 12, …


Macromolecular Crowding, Phase Separation, And Homeostasis In The Orchestration Of Bacterial Cellular Functions, Begoña Monterroso, William Margolin, Arnold J Boersma, Germán Rivas, Bert Poolman, Silvia Zorrilla Feb 2024

Macromolecular Crowding, Phase Separation, And Homeostasis In The Orchestration Of Bacterial Cellular Functions, Begoña Monterroso, William Margolin, Arnold J Boersma, Germán Rivas, Bert Poolman, Silvia Zorrilla

Journal Articles

Macromolecular crowding affects the activity of proteins and functional macromolecular complexes in all cells, including bacteria. Crowding, together with physicochemical parameters such as pH, ionic strength, and the energy status, influences the structure of the cytoplasm and thereby indirectly macromolecular function. Notably, crowding also promotes the formation of biomolecular condensates by phase separation, initially identified in eukaryotic cells but more recently discovered to play key functions in bacteria. Bacterial cells require a variety of mechanisms to maintain physicochemical homeostasis, in particular in environments with fluctuating conditions, and the formation of biomolecular condensates is emerging as one such mechanism. In this …


Microbial Co-Occurrences On Catheters From Long-Term Catheterized Patients, Taylor M Nye, Zongsen Zou, Chloe L P Obernuefemann, Jerome S Pinkner, Erin Lowry, Kent Kleinschmidt, Karla Bergeron, Aleksandra Klim, Karen W Dodson, Ana L Flores-Mireles, Jennifer N Walker, Daniel Garrett Wong, Alana Desai, Michael G Caparon, Scott J Hultgren Jan 2024

Microbial Co-Occurrences On Catheters From Long-Term Catheterized Patients, Taylor M Nye, Zongsen Zou, Chloe L P Obernuefemann, Jerome S Pinkner, Erin Lowry, Kent Kleinschmidt, Karla Bergeron, Aleksandra Klim, Karen W Dodson, Ana L Flores-Mireles, Jennifer N Walker, Daniel Garrett Wong, Alana Desai, Michael G Caparon, Scott J Hultgren

Journal Articles

Catheter-associated urinary tract infections (CAUTIs), a common cause of healthcare-associated infections, are caused by a diverse array of pathogens that are increasingly becoming antibiotic resistant. We analyze the microbial occurrences in catheter and urine samples from 55 human long-term catheterized patients collected over one year. Although most of these patients were prescribed antibiotics over several collection periods, their catheter samples remain colonized by one or more bacterial species. Examination of a total of 366 catheter and urine samples identify 13 positive and 13 negative genus co-occurrences over 12 collection periods, representing associations that occur more or less frequently than expected …


Illuminating Type Iv Secretion-Mediated Dna Trafficking Through Long Filaments, Peter J Christie Dec 2023

Illuminating Type Iv Secretion-Mediated Dna Trafficking Through Long Filaments, Peter J Christie

Journal Articles

No abstract provided.


Oral Dosages Of The Nsaid Aspirin Decreased The Growth Rate Of Species Found In The Human Gut Microbiome Including Akkermansia Muciniphila, Bacteroides Fragilis, Clostridium Sordellii, And Clostridium Difficile, Wyatt H. Greenbaum, Garrett J. Greenbaum, Anna Spiezio Sep 2023

Oral Dosages Of The Nsaid Aspirin Decreased The Growth Rate Of Species Found In The Human Gut Microbiome Including Akkermansia Muciniphila, Bacteroides Fragilis, Clostridium Sordellii, And Clostridium Difficile, Wyatt H. Greenbaum, Garrett J. Greenbaum, Anna Spiezio

PANDION: The Osprey Journal of Research and Ideas

Over past few decades, new insight has been revealed in the scientific community about the importance of the human gut microbiome relating to general health. It is known that imbalances in the species that reside in the human gut can cause organism-wide problems in humans. When prescribing or injecting oral medications, the thought of the downstream effects on the gut microbiome are not always considered. By exposing known healthy members of the gut; Akkermansia muciniphila, Bacteroides fragilis, Clostridium sordellii, and Clostridium difficile to the Aspirin, this study attempted to provide insight into the effects of the drug on bacterial growth. …


Estimated Impact Of Low Isolate Numbers On The Reliability Of Cumulative Antibiogram Data, Christian Tran, John Hargy, Bryan Hess, Matthew Pettengill Feb 2023

Estimated Impact Of Low Isolate Numbers On The Reliability Of Cumulative Antibiogram Data, Christian Tran, John Hargy, Bryan Hess, Matthew Pettengill

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Antibiograms are cumulative reports of antimicrobial susceptibility results that are used to guide the selection of empirical antibiotic therapy. Although Clinical and Laboratory Standards Institute (CLSI) guidelines recommend including only organisms that have at least 30 isolates in an antibiogram, previous studies demonstrated that adherence to this recommendation is highly variable. This paper aims to model the impact of small sample sizes on expected levels of error in cumulative antibiograms by comparing percent susceptibility results for random samples to those of the larger, entire data set. The results demonstrate relatively high error rates when utilizing low numbers of isolates in …


Comparing The Microbiomes Of Dental Plaques In 19th Century Ancestral Remains, Ananya Udyaver Jan 2023

Comparing The Microbiomes Of Dental Plaques In 19th Century Ancestral Remains, Ananya Udyaver

Undergraduate Research Posters

During the construction of VCU’s Hermes A. Kontos Medical Sciences Building in April 1994, nineteenth century ancestral remains were found in an abandoned well on the Medical College of Virginia (MCV) campus. This well, now known as the East Marshall Street Well (EMSW), is thought to have been used as a disposal location for cadaver dissection for surgical and other medical waste in the past. VCU is now seeking to use DNA sequencing technology to match and assemble bones from each individual for a proper burial, uncover the cultural and historical context in which these people lived, and bring a …


The Role Of Urinary Modulators In The Development Of Infectious Kidney Stones, Brendan Wallace Jul 2022

The Role Of Urinary Modulators In The Development Of Infectious Kidney Stones, Brendan Wallace

Electronic Thesis and Dissertation Repository

The pathogenesis of infectious kidney stones is poorly understood, while equally unclear is the role of urinary modulators and bacteria. An experimental model was created and utilized to test a variety of urinary modulators and bacterial strains commonly associated with struvite and calcium phosphate stones to evaluate their potential roles in influencing crystal formation. Modulators such as acids, citrate, and osteopontin had strong inhibitory effects on infectious crystal formation while the remaining modulators had neutral, mixed, or positive effects. Lastly, it was determined that the presence of urease may not directly lead to calcium phosphate and struvite stones in all …


Host And Gut Microbial Tryptophan Metabolism And Type 2 Diabetes: An Integrative Analysis Of Host Genetics, Diet, Gut Microbiome And Circulating Metabolites In Cohort Studies, Qibin Qi, Jun Li, Bing Yu, Jee-Young Moon, Jin C Chai, Jordi Merino, Jie Hu, Miguel Ruiz-Canela, Casey Rebholz, Zheng Wang, Mykhaylo Usyk, Guo-Chong Chen, Bianca C Porneala, Wenshuang Wang, Ngoc Quynh Nguyen, Elena V Feofanova, Megan L Grove, Thomas J Wang, Robert E Gerszten, Josée Dupuis, Jordi Salas-Salvadó, Wei Bao, David L Perkins, Martha L Daviglus, Bharat Thyagarajan, Jianwen Cai, Tao Wang, Joann E Manson, Miguel A Martínez-González, Elizabeth Selvin, Kathryn M Rexrode, Clary B Clish, Frank B Hu, James B Meigs, Rob Knight, Robert D Burk, Eric Boerwinkle, Robert C Kaplan Jun 2022

Host And Gut Microbial Tryptophan Metabolism And Type 2 Diabetes: An Integrative Analysis Of Host Genetics, Diet, Gut Microbiome And Circulating Metabolites In Cohort Studies, Qibin Qi, Jun Li, Bing Yu, Jee-Young Moon, Jin C Chai, Jordi Merino, Jie Hu, Miguel Ruiz-Canela, Casey Rebholz, Zheng Wang, Mykhaylo Usyk, Guo-Chong Chen, Bianca C Porneala, Wenshuang Wang, Ngoc Quynh Nguyen, Elena V Feofanova, Megan L Grove, Thomas J Wang, Robert E Gerszten, Josée Dupuis, Jordi Salas-Salvadó, Wei Bao, David L Perkins, Martha L Daviglus, Bharat Thyagarajan, Jianwen Cai, Tao Wang, Joann E Manson, Miguel A Martínez-González, Elizabeth Selvin, Kathryn M Rexrode, Clary B Clish, Frank B Hu, James B Meigs, Rob Knight, Robert D Burk, Eric Boerwinkle, Robert C Kaplan

Journal Articles

OBJECTIVE: Tryptophan can be catabolised to various metabolites through host kynurenine and microbial indole pathways. We aimed to examine relationships of host and microbial tryptophan metabolites with incident type 2 diabetes (T2D), host genetics, diet and gut microbiota.

METHOD: We analysed associations between circulating levels of 11 tryptophan metabolites and incident T2D in 9180 participants of diverse racial/ethnic backgrounds from five cohorts. We examined host genome-wide variants, dietary intake and gut microbiome associated with these metabolites.

RESULTS: Tryptophan, four kynurenine-pathway metabolites (kynurenine, kynurenate, xanthurenate and quinolinate) and indolelactate were positively associated with T2D risk, while indolepropionate was inversely associated with …


Safety And Efficacy Of Silver-Coated Biomaterials In Vivo, Megan Klem, Darien L. Seidman, Rahyan Mahmoud, Manuella Adu, Lei Yu, Jeffrey Hettinger, Renee M Demarest May 2022

Safety And Efficacy Of Silver-Coated Biomaterials In Vivo, Megan Klem, Darien L. Seidman, Rahyan Mahmoud, Manuella Adu, Lei Yu, Jeffrey Hettinger, Renee M Demarest

Rowan-Virtua Research Day

Overtreatment and overuse of antibiotics in healthcare and agricultural settings have contributed to the selective pressure on bacterial strains to develop resistance. Resistance can develop as a result of mutations and subsequent resistance genes that allow bacteria to survive against antibiotics. Novel silver-oxide coatings were developed and were previously demonstrated to prevent adhesion of gram-negative bacteria (Escherichia Coli and Pseudomonas Aeruginosa) to the disc, but did not prevent gram-positive bacterial adherence (Streptococcus Aureus). In order to determine whether the silver-oxide coatings are bacterial static and may be preventing progression to biofilm formation, in vivo analysis of S. Aureus attached to …


Cellular Dynamics And Disease Outcome Of Type 3 Streptococcus Pneumoniae Clinical Isolates Differ Between Strains, Taylor Rae Plunkett White Apr 2022

Cellular Dynamics And Disease Outcome Of Type 3 Streptococcus Pneumoniae Clinical Isolates Differ Between Strains, Taylor Rae Plunkett White

Theses and Dissertations (ETD)

Streptococcus pneumoniae is a bacterial pathogen that continues to be a major cause of disease around the world. It is not only the number one cause of bacterial pneumonia but also the cause of about 15% of the deaths of children under 5 around the world. There is a lot of research done on this organism, but with around 100 known serotypes and each one producing a unique capsule, there is still much more to be studied. The Etiology of Pneumonia in the Community (EPIC) study conducted by the CDC observed the burden of hospitalizations caused by pneumonia while determining …


Assessment Of Diversity Of Antimicrobial Resistance Phenotypes And Genotypes Of Mannheimia Haemolytica Isolates From Bovine Nasopharyngeal Swabs, Hannah F. Carter, Robert W. Wills, Matthew A. Scott, Alexis C. Thompson, Randall S. Singer, John Dustin Loy, Brandi B. Karisch, William B. Epperson, Amelia R. Woolums Mar 2022

Assessment Of Diversity Of Antimicrobial Resistance Phenotypes And Genotypes Of Mannheimia Haemolytica Isolates From Bovine Nasopharyngeal Swabs, Hannah F. Carter, Robert W. Wills, Matthew A. Scott, Alexis C. Thompson, Randall S. Singer, John Dustin Loy, Brandi B. Karisch, William B. Epperson, Amelia R. Woolums

School of Veterinary and Biomedical Sciences: Faculty Publications

The threat of bovine respiratory disease (BRD) for cattle operations is exacerbated by increasing prevalence of antimicrobial resistance (AMR) in Mannheimia haemolytica, a leading cause of BRD. Characterization of AMR in M. haemolytica by culture and susceptibility testing is complicated by uncertainty regarding the number of colonies that must be selected to accurately characterize AMR phenotypes (antibiograms) and genotypes in a culture. The study objective was to assess phenotypic and genotypic diversity of M. haemolytica isolates on nasopharyngeal swabs (NPS) from 28 cattle at risk for BRD or with BRD. NPS were swabbed onto five consecutive blood agar plates; …


A Twist To The Kirby-Bauer Disk Diffusion Susceptibility Test: An Accessible Laboratory Experiment Comparing Haloferax Volcanii And Escherichia Coli Antibiotic Susceptibility To Highlight The Unique Cell Biology Of Archaea, Heather Schiller, Criston Young, Stefan Schulze, Manuela Tripepi, Mechthild Pohlschroder Jan 2022

A Twist To The Kirby-Bauer Disk Diffusion Susceptibility Test: An Accessible Laboratory Experiment Comparing Haloferax Volcanii And Escherichia Coli Antibiotic Susceptibility To Highlight The Unique Cell Biology Of Archaea, Heather Schiller, Criston Young, Stefan Schulze, Manuela Tripepi, Mechthild Pohlschroder

College of Life Sciences Faculty Papers

Archaea, once thought to only live in extreme environments, are present in many ecosystems, including the human microbiome, and they play important roles ranging from nutrient cycling to bioremediation. Yet this domain is often overlooked in microbiology classes and rarely included in laboratory exercises. Excluding archaea from high school and undergraduate curricula prevents students from learning the uniqueness and importance of this domain. Here, we have modified a familiar and popular microbiology experiment-the Kirby-Bauer disk diffusion antibiotic susceptibility test-to include, together with the model bacterium Escherichia coli, the model archaeon Haloferax volcanii. Students will learn the differences and similarities between …


Predicting Cancer Immunotherapy Response From Gut Microbiomes Using Machine Learning Models, Hai Liang, Jay-Hyun Jo, Zhiwei Zhang, Margaret A Macgibeny, Jungmin Han, Diana M Proctor, Monica E Taylor, You Che, Paul Juneau, Andrea B Apolo, John A Mcculloch, Diwakar Davar, Hassane M Zarour, Amiran K Dzutsev, Isaac Brownell, Giorgio Trinchieri, James L Gulley, Heidi H Kong Jan 2022

Predicting Cancer Immunotherapy Response From Gut Microbiomes Using Machine Learning Models, Hai Liang, Jay-Hyun Jo, Zhiwei Zhang, Margaret A Macgibeny, Jungmin Han, Diana M Proctor, Monica E Taylor, You Che, Paul Juneau, Andrea B Apolo, John A Mcculloch, Diwakar Davar, Hassane M Zarour, Amiran K Dzutsev, Isaac Brownell, Giorgio Trinchieri, James L Gulley, Heidi H Kong

Journal Articles

Cancer immunotherapy has significantly improved patient survival. Yet, half of patients do not respond to immunotherapy. Gut microbiomes have been linked to clinical responsiveness of melanoma patients on immunotherapies; however, different taxa have been associated with response status with implicated taxa inconsistent between studies. We used a tumor-agnostic approach to find common gut microbiome features of response among immunotherapy patients with different advanced stage cancers. A combined meta-analysis of 16S rRNA gene sequencing data from our mixed tumor cohort and three published immunotherapy gut microbiome datasets from different melanoma patient cohorts found certain gut bacterial taxa correlated with immunotherapy response …


Microbial Influence On Alzheimer's Disease, Ashley N. Hamby Sep 2021

Microbial Influence On Alzheimer's Disease, Ashley N. Hamby

The Cardinal Edge

No abstract provided.


Infection And Risk Of Parkinson's Disease, Richard Jay Smeyne, Alastair J Noyce, Matthew D. Byrne, Rodolfo Savica, Connie Marras Feb 2021

Infection And Risk Of Parkinson's Disease, Richard Jay Smeyne, Alastair J Noyce, Matthew D. Byrne, Rodolfo Savica, Connie Marras

Department of Neuroscience Faculty Papers

Parkinson's disease (PD) is thought to be caused by a combination of genetic and environmental factors. Bacterial or viral infection has been proposed as a potential risk factor, and there is supporting although not entirely consistent epidemiologic and basic science evidence to support its role. Encephalitis caused by influenza has included parkinsonian features. Epidemiological evidence is most compelling for an association between PD and hepatitis C virus. Infection with Helicobacter pylori may be associated not only with PD risk but also response to levodopa. Rapidly evolving knowledge regarding the role of the microbiome also suggests a role of resident bacteria …


The Hocl Response Of Escherichia Coli., Rhea Marie Derke Jan 2021

The Hocl Response Of Escherichia Coli., Rhea Marie Derke

All ETDs from UAB

Inflammatory bowel diseases (IBDs), like Chron’s disease and ulcerative colitis, affect millions of people worldwide. There are limited treatment options available for these diseases because their direct causes are unknown. IBDs are characterized by chronic inflammation of the gastrointestinal tract and changes in the composition of the gut microbiome. Enterobacteria, including Escherichia coli, bloom to high levels in the gut during inflammation and contribute to the pathology of IBDs. E. coli must tolerate high levels of antimicrobial compounds produced by the immune system to survive during persistent inflammation. A large proportion of such compounds are reactive oxygen and reactive chlorine …


Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding Aug 2020

Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding

Electronic Theses and Dissertations

Despite efforts to decrease the global health burden of malaria, infections with Plasmodium species continue to cause over 200 million episodes of malaria each year which resulted in 405,000 deaths in 2018 [1]. One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through activities of heme oxygenase I (HO-I) )-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had impaired clearance of systemic Listeria monocytogenes (Lm) during …


Triggers Of Inflammatory Heart Disease, Ninaad Lasrado, Bharathi Yalaka, Jay Reddy Jan 2020

Triggers Of Inflammatory Heart Disease, Ninaad Lasrado, Bharathi Yalaka, Jay Reddy

School of Veterinary and Biomedical Sciences: Faculty Publications

Inflammatory heart disease (IHD) is a group of diseases that includes pericarditis, myocarditis, and endocarditis. Although males appear to be more commonly affected than females, IHD can be seen in any age group. While the disease can be self-limiting leading to full recovery, affected individuals can develop chronic disease, suggesting that identification of primary triggers is critical for successful therapies. Adding to this complexity, however, is the fact that IHD can be triggered by a variety of infectious and non-infectious causes that can also occur as secondary events to primary insults. In this review, we discuss the immunological insights into …


Listeria Monocytogenes As A Vector For Cancer Immunotherapy: Current Understanding And Progress, John C. Flickinger, Ulrich Rodeck, Adam E. Snook Sep 2018

Listeria Monocytogenes As A Vector For Cancer Immunotherapy: Current Understanding And Progress, John C. Flickinger, Ulrich Rodeck, Adam E. Snook

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Listeria monocytogenes, a Gram-positive facultative anaerobic bacterium, is becoming a popular vector for cancer immunotherapy. Indeed, multiple vaccines have been developed utilizing modified Listeria as a tool for generating immune responses against a variety of cancers. Moreover, over a dozen clinical trials testing Listeria cancer vaccines are currently underway, which will help to understand the utility of Listeria vaccines in cancer immunotherapy. This review aims to summarize current views on how Listeria-based vaccines induce potent antitumor immunity and the current state of Listeria-based cancer vaccines in clinical trials. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.


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 Nov 2017

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 Aug 2017

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 …


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 Apr 2017

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 …


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 Feb 2017

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 …


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 Jan 2017

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. …


Initiator Trna Genes Template The 3' Cca End At High Frequencies In Bacteria., David H. Ardell, Ya-Ming Hou Dec 2016

Initiator Trna Genes Template The 3' Cca End At High Frequencies In Bacteria., David H. Ardell, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

BACKGROUND: While the CCA sequence at the mature 3' end of tRNAs is conserved and critical for translational function, a genetic template for this sequence is not always contained in tRNA genes. In eukaryotes and Archaea, the CCA ends of tRNAs are synthesized post-transcriptionally by CCA-adding enzymes. In Bacteria, tRNA genes template CCA sporadically.

RESULTS: In order to understand the variation in how prokaryotic tRNA genes template CCA, we re-annotated tRNA genes in tRNAdb-CE database version 0.8. Among 132,129 prokaryotic tRNA genes, initiator tRNA genes template CCA at the highest average frequency (74.1%) over all functional classes except selenocysteine and …


Rna-Seq Of Borrelia Burgdorferi In Multiple Phases Of Growth Reveals Insights Into The Dynamics Of Gene Expression, Transcriptome Architecture, And Noncoding Rnas, William K. Arnold, Christina R. Savage, Catherine A. Brissette, Janakiram Seshu, Jonathan Livny, Brian Stevenson Oct 2016

Rna-Seq Of Borrelia Burgdorferi In Multiple Phases Of Growth Reveals Insights Into The Dynamics Of Gene Expression, Transcriptome Architecture, And Noncoding Rnas, William K. Arnold, Christina R. Savage, Catherine A. Brissette, Janakiram Seshu, Jonathan Livny, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Borrelia burgdorferi, the agent of Lyme disease, differentially expresses numerous genes and proteins as it cycles between mammalian hosts and tick vectors. Insights on regulatory mechanisms have been provided by earlier studies that examined B. burgdorferi gene expression patterns during cultivation. However, prior studies examined bacteria at only a single time point of cultivation, providing only a snapshot of what is likely a dynamic transcriptional program driving B. burgdorferi adaptations to changes during culture growth phases. To address that concern, we performed RNA sequencing (RNA-Seq) analysis of B. burgdorferi cultures at early-exponential, mid-exponential, and early-stationary phases …


Changing Diagnostic Methods And Increased Detection Of Verotoxigenic Escherichia Coli, Ireland, Thomas Rice, Noreen Quinn, Roy D. Sleator, Brigid Lucey Sep 2016

Changing Diagnostic Methods And Increased Detection Of Verotoxigenic Escherichia Coli, Ireland, Thomas Rice, Noreen Quinn, Roy D. Sleator, Brigid Lucey

Department of Biological Sciences Publications

The recent paradigm shift in infectious disease diagnosis from culture-based to molecular-based approaches is exemplified in the findings of a national study assessing the detection of verotoxigenic Escherichia coli infections in Ireland. The methodologic changes have been accompanied by a dramatic increase in detections of non-O157 verotoxigenic E. coli serotypes.


Gene Deletion By Fluorescence-Reported Allelic Exchange Mutagenesis In Chlamydia Trachomatis, Konrad E. Mueller, Katerina Wolf, Kenneth A. Fields Jan 2016

Gene Deletion By Fluorescence-Reported Allelic Exchange Mutagenesis In Chlamydia Trachomatis, Konrad E. Mueller, Katerina Wolf, Kenneth A. Fields

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Although progress in Chlamydia genetics has been rapid, genomic modification has previously been limited to point mutations and group II intron insertions which truncate protein products. The bacterium has thus far been intractable to gene deletion or more-complex genomic integrations such as allelic exchange. Herein, we present a novel suicide vector dependent on inducible expression of a chlamydial gene that renders Chlamydia trachomatis fully genetically tractable and permits rapid reverse genetics by fluorescence-reported allelic exchange mutagenesis (FRAEM). We describe the first available system of targeting chlamydial genes for deletion or allelic exchange as well as curing plasmids from C. trachomatis …