Examining Pathogenesis And Preventatives In Spontaneous And Staphylococcus-Induced Bacterial Chondronecrosis With Osteomyelitis In Broilers,
2020
University of Arkansas, Fayetteville
Examining Pathogenesis And Preventatives In Spontaneous And Staphylococcus-Induced Bacterial Chondronecrosis With Osteomyelitis In Broilers, Nnamdi Simon Ekesi
Graduate Theses and Dissertations
Bacterial chondronecrosis with osteomyelitis is the most important cause of lameness in broilers. This is important to poultry production, as it poses animal welfare issues, and causes a significant loss in revenue. The remediation of this disease requires the study of its etiology with fitting models and evaluating preventatives. The research reported herein covers genomic virulence analysis of BCO isolates, mainly Staphylococcus aureus, and Escherichia coli retrieved from lame birds. We found that S. aureus isolates were closest to chicken strains in Europe but may have been in the Arkansas area for a decade. Phylogenomics suggest our S. aureus is …
Increasing Antibiotic Resistance In Shigella Bacteria In The United States,
2020
Georgia College and State University
Increasing Antibiotic Resistance In Shigella Bacteria In The United States, William J. Pharr
The Corinthian
Shigella bacteria cause half a million infections, 6,000 hospitalizations, and 70 deaths annually in the United States. These bacteria are of particular concern due to their high survivability, low infectious dose, and high adaptability. Cases of shigellosis from Shigella sonnei are becoming a more prevalent issue in the U.S. as the bacteria continues to develop higher resistance to today’s strongest antibiotics. Much of this resistance is connected to the exchange of genes between strains of Shigella due to insertion sequences (IS), intercontinental travel, and men who have sex with men (MSM). As a result of increased resistance, the use of …
Aspergillus Niger Decreases Bioavailability Of Arsenic(V) Via Biotransformation Of Manganese Oxide Into Biogenic Oxalate Minerals,
2020
Comenius University in Bratislava
Aspergillus Niger Decreases Bioavailability Of Arsenic(V) Via Biotransformation Of Manganese Oxide Into Biogenic Oxalate Minerals, Bence Farkas, Marek Kolenčík, Miroslav Hain, Edmund Dobročka, Gabriela Kratošová, Marek Bujdoš, Huan Feng, Yang Deng, Qian Yu, Ramakanth Illa, B. Ratna Sunil, Hyunjung Kim, Peter Matúš, Martin Urík
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The aim of this work was to evaluate the transformation of manganese oxide (hausmannite) by microscopic filamentous fungus Aspergillus niger and the effects of the transformation on mobility and bioavailability of arsenic. Our results showed that the A. niger strain CBS 140837 greatly affected the stability of hausmannite and induced its transformation into biogenic crystals of manganese oxalates—falottaite and lindbergite. The transformation was enabled by fungal acidolysis of hausmannite and subsequent release of manganese ions into the culture medium. While almost 45% of manganese was bioextracted, the arsenic content in manganese precipitates increased throughout the 25-day static cultivation of fungus. …
Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease,
2020
University of Nebraska-Lincoln
Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease, Armando Lerma
Department of Food Science and Technology: Dissertations, Theses, and Student Research
Clostridioides difficile is recognized as one of the most important pathogens in hospital and community healthcare settings. The clinical outcome of infection of toxigenic C. difficile infection (CDI) ranges from asymptomatic colonization to fulminant pseudomembranous colitis and death. In recent studies, it has been suggested that a high proportion of nosocomial CDI cases are transmitted from asymptomatic carriers which might be acting as infection reservoirs. Understanding what causes the different responses to infection could lead to the development of novel prevention and treatment strategies. Although several explanations have been proposed to explain variations in susceptibility, understanding of the exact mechanisms …
Antibacterial Action Of Graphene Oxide Towards Bacteria And Its Toxicological Effects On Human Epidermal Keratinocytes,
2020
Universiti Malaya
Antibacterial Action Of Graphene Oxide Towards Bacteria And Its Toxicological Effects On Human Epidermal Keratinocytes, Thiruchelvi Pulingam
Student Works (2020-2029)
The antibacterial nature of graphene oxide (GO) has stimulated wide interest in the medical field. Although the antibacterial activity of GO towards bacteria has been well studied, a deeper understanding of the mechanism of action of GO is still lacking. The objectives of the study were to characterize the physicochemical properties of GO, to determine the antibacterial and antibiofilm activity and the mechanistic action of GO against Gram-positive Staphylococcus aureus and Enterococcus faecalis and Gram-negative Escherichia coli and Pseudomonas aeruginosa, to determine the synergistic behaviour of GO with selected antibiotics against bacterial cells in suspension and biofilm and to determine …
Expanding Magnetic Organelle Biogenesis In The Domain Bacteria,
2020
Chinese Academy of Sciences
Expanding Magnetic Organelle Biogenesis In The Domain Bacteria, Wei Lin, Wensi Zhang, Greig A. Paterson, Qiyun Zhu, Xiang Zhao, Rob Knight, Dennis A. Bazylinski, Andrew P. Roberts, Yongxin Pan
Life Sciences Faculty Research
Background: The discovery of membrane-enclosed, metabolically functional organelles in Bacteria has transformed our understanding of the subcellular complexity of prokaryotic cells. Biomineralization of magnetic nanoparticles within magnetosomes by magnetotactic bacteria (MTB) is a fascinating example of prokaryotic organelles. Magnetosomes, as nano-sized magnetic sensors in MTB, facilitate cell navigation along the local geomagnetic field, a behaviour referred to as magnetotaxis or microbial magnetoreception. Recent discovery of novel MTB outside the traditionally recognized taxonomic lineages suggests that MTB diversity across the domain Bacteria are considerably underestimated, which limits understanding of the taxonomic distribution and evolutionary origin of magnetosome organelle biogenesis. Results: Here, …
Cryo‑Electron Microscopy Structure Of The 70s Ribosome From Enterococcus Faecalis,
2020
Brown University
Cryo‑Electron Microscopy Structure Of The 70s Ribosome From Enterococcus Faecalis, Eileen L. Murphy, Kavindra V. Singh, Bryant Avila, Torsten Kleffmann, Steven T. Gregory, Barbara E. Murray, Kurt L. Krause, Reza Khayat, Gerwald Jogl
Publications and Research
Enterococcus faecalis is a gram-positive organism responsible for serious infections in humans, but as with many bacterial pathogens, resistance has rendered a number of commonly used antibiotics ineffective. Here, we report the cryo-EM structure of the E. faecalis 70S ribosome to a global resolution of 2.8 Å. Structural differences are clustered in peripheral and solvent exposed regions when compared with Escherichia coli, whereas functional centres, including antibiotic binding sites, are similar to other bacterial ribosomes. Comparison of intersubunit conformations among five classes obtained after three-dimensional classification identifies several rotated states. Large ribosomal subunit protein bL31, which forms intersubunit bridges to …
Biofilm Forming Ability Of Bacteria Isolated From Dental Caries: With Reference To Streptococcus Species,
2020
Rajiv Gandhi Institute of IT and Biotechnology, Bharati Vidyapeeth (Deemed to be University), Pune, India
Biofilm Forming Ability Of Bacteria Isolated From Dental Caries: With Reference To Streptococcus Species, Sonali Kaustubh Ambulkar, Vidya Tale, Abhijit Jadhav, Komal Kulkarni
Future Dental Journal
Dental caries is formed by the group of microorganisms attached to a tooth surface embedded in a matrix of polymers. Biofilm plays an important role in the development of dental caries, plaque and other periodontal diseases. The present study is aimed to isolate, identify and characterize bacteria from dental caries. The ability of biofilm formation of these isolates was confirmed by Congo red agar method, Tube method and Microtitre plate method. High biofilm-forming bacteria were identified by 16S rRNA sequencing. Streptococcus mutans, Streptococcus anginosus, Enterococcus faecalis and Rothia dentocariosa are the predominant biofilm forming bacteria associated with dental caries.
Mechanism Of Translation Inhibition By Type Ii Gnat Toxin Atat2,
2020
Skolkovo Institute of Science and Technology
Mechanism Of Translation Inhibition By Type Ii Gnat Toxin Atat2, Stepan V Ovchinnikov, Dmitry Bikmetov, Alexei Livenskyi, Marina Serebryakova, Brendan Wilcox, Kyle Mangano, Dmitrii I Shiriaev, Ilya A Osterman, Petr V Sergiev, Sergei Borukhov, Nora Vazquez-Laslop, Alexander S Mankin, Konstantin Severinov, Svetlana Dubiley
Rowan-Virtua School of Osteopathic Medicine Departmental Research
Type II toxin-antitoxins systems are widespread in prokaryotic genomes. Typically, they comprise two proteins, a toxin, and an antitoxin, encoded by adjacent genes and forming a complex in which the enzymatic activity of the toxin is inhibited. Under stress conditions, the antitoxin is degraded liberating the active toxin. Though thousands of various toxin-antitoxins pairs have been predicted bioinformatically, only a handful has been thoroughly characterized. Here, we describe the AtaT2 toxin from a toxin-antitoxin system from Escherichia coli O157:H7. We show that AtaT2 is the first GNAT (Gcn5-related N-acetyltransferase) toxin that specifically targets charged glycyl tRNA. In vivo, the AtaT2 …
Glycan-Dependent Adherence And Skin Colonization Of Staphylococcus Epidermidis Mediated By The Surface Protein Aap.,
2020
University of Nebraska Medical Center
Glycan-Dependent Adherence And Skin Colonization Of Staphylococcus Epidermidis Mediated By The Surface Protein Aap., Paroma Roy
Theses & Dissertations
Skin-dwelling coagulase-negative staphylococci (CoNS), a group of bacteria that includes Staphylococcus epidermidis, has been implicated to promote skin immunity and antimicrobial defense and prohibit colonization of skin by pathogens like S. aureus. As a skin inhabitant, S. epidermidis lives in tight association with corneocytes, the cells that constitute the uppermost layer of the skin epidermis. Yet the molecular mechanism responsible for adhesion of S. epidermidis to corneocytes remains poorly understood. Our study indicated that Accumulation-associated protein (Aap), a cell-wall anchored, fibrillar adhesin mediates bacterial-host interaction, demonstrated by significantly higher corneocyte binding by Aap-positive 1457 mutants as compared to …
Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules.,
2020
University of Louisville
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 …
Identification And Structural Characterization Functional Motifs In The Porphyromonas Gingivalis Mfa1 Short Fimbria.,
2020
University of Louisville
Identification And Structural Characterization Functional Motifs In The Porphyromonas Gingivalis Mfa1 Short Fimbria., Mohammad K. Roky
Electronic Theses and Dissertations
Porphyromonas gingivalis is a causative agent of periodontal disease, initially colonizes the oral cavity by adhering to commensal streptococci. Adherence requires the interaction of the minor fimbrial protein (Mfa1) of P. gingivalis with streptococcal antigen I/II (Ag I/II). A peptide derived from Ag I/II peptide has been well characterized and shown to significantly reduce P. gingivalis colonization and bone loss in vivo, suggesting that this interaction represents a potential target for therapeutic intervention. However, the functional motifs of Mfa1 involved in the interaction with Ag I/II remain uncharacterized. A series of N- and C-terminal peptide fragments of Mfa1 were …
Mutations Within And Between Early Cell Division Proteins And Their Effects On Division Regulation In Escherichia Coli,
2020
The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences
Mutations Within And Between Early Cell Division Proteins And Their Effects On Division Regulation In Escherichia Coli, Kara Schoenemann
Dissertations and Theses (Open Access)
Cell division is a highly regulated process that must coordinate multiple implicit activities in different locations in the cell simultaneously. E. coli utilizes a macromolecular machine known as the divisome to accomplish cytokinesis. Assembly of the divisome begins with the assembly of a simpler structure known as the proto-ring. The proto-ring consists mainly of three essential proteins: FtsZ and its membrane tethers FtsA and ZipA. In this work, I aimed to understand the early regulation of division in E. coli by investigating the structure/function relationships of the proto-ring proteins, as well as their interactions with one another and how these …
Effect Of Botulinum Toxin Injection On Asymmetric Lower Face And Chin Deviation,
2020
Yonsei University College of Dentistry
Effect Of Botulinum Toxin Injection On Asymmetric Lower Face And Chin Deviation, Dongwook Kim, Ju-Hyun Park, Vittorio Favero, James Mah, Young-Soo Jung, Seong Taek Kim
Dental Medicine Faculty Research
The purpose of this study was to compare the efficacy of botulinum toxin (BoNT) in masseter muscle reduction depending on the amount of chin deviation. Exploring distinctive effects of BoNT relative to the characteristics of facial asymmetry will aid in planning and predicting treatment outcomes. Sixteen adult volunteers were classified into two groups according to the degree of menton deviation observed in posteroanterior cephalograms. Eight had a menton deviation of 3 mm or more and the other eight had less than 3 mm. A total of 25 Units of BoNT was injected into the unilateral masseter muscle of the prominent …
Improved Antimicrobial Properties Of Silver Nanoparticles With Methylene Blue,
2020
Western Kentucky University
Improved Antimicrobial Properties Of Silver Nanoparticles With Methylene Blue, Ermek Belekov
Masters Theses & Specialist Projects
Photosensitizing agents are the cornerstone of photodynamic therapy (PDT) that play essential role in deactivation process of multidrug resistant pathogens and tumor treatments. In this work we studied a photosensitizing agent made from mixture of silver nanoparticles (Ag NPs) and methylene blue (MB) which possess improved important characteristics like high photostability and high singlet oxygen yield. Ag NPs were synthesized by pulsed laser ablation technique in different aqueous solutions like Polyvinylpyrrolidone (PVP), citrate and Deionized (DI) water. The synthesized Ag NPs were characterized in depth using with transmission electron microscopy (TEM), UVVisible (UV-Vis), and photoluminescence (PL) spectra. Ag NPs were …
Suspended Carbon Nanowire Biosensor For Rapid And Label-Free Salmonella Detection,
2020
Universiti Malaya
Suspended Carbon Nanowire Biosensor For Rapid And Label-Free Salmonella Detection, Thiha Aung
Student Works (2020-2029)
Carbon, the building block life, is rapidly becoming the building block of nextgeneration electronics and sensor materials. Of many ways to handle nanocarbon materials, Carbon Microelectromechanical Systems (C-MEMS) emerges as a unique way for top-down fabrication of three-dimensional carbon micro to nanostructures. In this work, the use of C-MEMS techniques in nanowire biosensor fabrication is explored. Two main hindrances in the use of C-MEMS carbon structures for biosensing lie in miniaturization to nanoscale sensor material and inertness of as-fabricated carbon. This dissertation presents ways to overcome these limitations. First, miniaturization to patterned sub-100 nm carbon nanowires was achieved by optimization …
Phenotypic Switching Of Bacterial Cells In Extreme Environments,
2020
University of Arkansas, Fayetteville
Phenotypic Switching Of Bacterial Cells In Extreme Environments, Sudip Nepal
Graduate Theses and Dissertations
A large number of terrestrial microbial lives thrive in extremes of environmental conditions, including extremes of pressure, temperature, salinity, pH, and a combination of them. For example, all the marine biomass thrive at high hydrostatic pressure depending on depth. The temperature in the ocean can be very high near the hydrothermal vents and salinity and pH depends on the composition of salt in the surrounding areas. On the surface, hot springs, lakes and geysers provide high temperature conditions, while many places are permafrost regions with subzero temperatures. There is an emerging body of work on the viability, genomics, and metagenomics …
Antimicrobial Strategies For Topical Applications,
2020
Louisiana State University and Agricultural and Mechanical College
Antimicrobial Strategies For Topical Applications, Kelsey Marie Lopez
LSU Doctoral Dissertations
Bacteria can thrive in diverse environments and are often harmless or beneficial. Bacteria in digestive tracts is one example of beneficial bacteria; however, bacteria can be harmful and when this type proliferates, it can cause infections within hosts. Bacterial infections are easily treated with antibiotics in most cases. However, bacteria are also capable of developing mutations which could cause them to become multi-drug resistant and eventually, “superbugs.” Therefore, the development of novel antimicrobial agents and materials capable of combating drug-resistant bacteria is necessary. Research presented in this dissertation focuses on different strategies for minimizing and preventing topical bacterial infections using …
Plant Defensin Antibacterial Mode Of Action Against Pseudomonas Species,
2020
Dakota State University
Plant Defensin Antibacterial Mode Of Action Against Pseudomonas Species, Andrew E. Sathoff, Shawn Lewenza, Deborah A. Samac
Research & Publications
Background: Though many plant defensins exhibit antibacterial activity, little is known about their antibacterial mode of action (MOA). Antimicrobial peptides with a characterized MOA induce the expression of multiple bacterial outer membrane modifications, which are required for resistance to these membrane-targeting peptides. Mini-Tn5- lux mutant strains of Pseudomonas aeruginosa with Tn insertions disrupting outer membrane protective modifications were assessed for sensitivity against plant defensin peptides. These transcriptional lux reporter strains were also evaluated for lux gene expression in response to sublethal plant defensin exposure. Also, a plant pathogen, Pseudomonas syringae pv. syringae was modified through transposon mutagenesis to …
Roadmap For Naming Uncultivated Archaea And Bacteria,
2020
Desert Research Institute
Roadmap For Naming Uncultivated Archaea And Bacteria, Alison E. Murray, John Freudenstein, Simonetta Gribaldo, Roland Hatzenpichler, Philip Hugenholtz, Peter Kämpfer, Konstantinos T. Konstantinidis, Christopher E. Lane, R. Thane Papke, Donovan H. Parks, Ramon Rossello-Mora, Matthew B. Stott, Cameron Thrash, Stephanus N. Venter, William B. Whitman, Silvia G. Acinas, Rudolf I. Amann, Karthik Anantharaman, Jean Armengaud, Brett J. Baker, Roman A. Barco, Helge B. Bode, Eric S. Boyd, Carrie L. Brady, Paul Carini, Patrick S. G. Chain, Daniel R. Colman, Kristen M. Deangelis, Maria Asuncion De Los Rios, Paulina Estrada-De Los Santos, Christopher A. Dunlop
Life Sciences Faculty Research
The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as ‘type material’, thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code …
