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Articles 1 - 12 of 12
Full-Text Articles in Molecular Biology
The Identification Of Two M20b Family Peptidases Required For Full Virulence In Staphylococcus Aureus, Nathanial James Torres, Devon Rizzo, Maria A. Reinberg, Mary-Elizabeth Jobson, Brendan C. Totzke, Jessica K. Jackson, Wenqi Yu, Lindsey Neil Shaw
The Identification Of Two M20b Family Peptidases Required For Full Virulence In Staphylococcus Aureus, Nathanial James Torres, Devon Rizzo, Maria A. Reinberg, Mary-Elizabeth Jobson, Brendan C. Totzke, Jessica K. Jackson, Wenqi Yu, Lindsey Neil Shaw
Molecular Biosciences Faculty Publications
We have previously demonstrated that deletion of an intracellular leucine aminopeptidase results in attenuated virulence of S. aureus. Herein we explore the role of 10 other aminopeptidases in S. aureus pathogenesis. Using a human blood survival assay we identified mutations in two enzymes from the M20B family (PepT1 and PepT2) as having markedly decreased survival compared to the parent. We further reveal that pepT1, pepT2 and pepT1/2 mutant strains are impaired in their ability to resist phagocytosis by, and engender survival within, human macrophages. Using a co-infection model of murine sepsis, we demonstrate impairment of dissemination and survival …
Roles Of Secreted Proteins And Iron Utilization Proteins In Virulence Of The Fish Pathogen Flavobacterium Columnare, Rachel Conrad
Roles Of Secreted Proteins And Iron Utilization Proteins In Virulence Of The Fish Pathogen Flavobacterium Columnare, Rachel Conrad
Theses and Dissertations
The Gram-negative bacterium Flavobacterium columnare is the causative agent of columnaris disease and is responsible for significant economic losses in aquaculture. Little is known regarding the virulence factors produced by F. columnare, and control measures are limited. Like many members of the phylum Bacteroidetes, F. columnare uses the type IX secretion system (T9SS) to secrete enzymes, adhesins, and proteins involved in gliding motility. When a core component of this system was deleted in the wild type strain, the resulting mutant was avirulent in zebrafish, rainbow trout, and channel catfish infection studies. This suggests that the individual secreted proteins may function …
Genome Sequencing Analysis Of Laboratory Isolate Of Francisella Noatunensis Subs. Orientalis, Joseph Paquette
Genome Sequencing Analysis Of Laboratory Isolate Of Francisella Noatunensis Subs. Orientalis, Joseph Paquette
Senior Honors Projects
Francisella noatunensis subs. orientalis is a known fish pathogen that has been most notably isolated from tilapia (Oreochromis niloticus) in Costa Rica. The genome of this Francisella species pathogen has been sequenced using Next-Generation Sequencing and been made available for the scientific community. Dr. Kathryn Ramsey’s research laboratory in the Department of Cell and Molecular Biology at the University of Rhode Island works with several Francisella species pathogens and is interested in identifying the differences, if any, between the known genome sequence of Francisella noatunensis and that of a laboratory isolate of the same species. With the use …
Transcriptional Silencing And Anti-Silencing Of Virulence Genes In The Bacterial Pathogen Shigella Flexneri: Virb, Dna Supercoiling, And The Histone-Like Nucleoid Structuring Protein, Michael Adam Picker
Transcriptional Silencing And Anti-Silencing Of Virulence Genes In The Bacterial Pathogen Shigella Flexneri: Virb, Dna Supercoiling, And The Histone-Like Nucleoid Structuring Protein, Michael Adam Picker
UNLV Theses, Dissertations, Professional Papers, and Capstones
Transcriptional silencing and anti-silencing affect many aspects of bacterial physiology, including virulence in bacterial pathogens. In Shigella species, a group of gram-negative pathogens that cause bacillary dysentery in humans, the histone-like nucleoid structuring protein (H-NS) transcriptionally silences virulence genes found on the large virulence plasmid while VirB anti-silences these genes. However, the mechanistic details of their interplay are not fully understood. To elucidate their regulatory mechanisms, I use the icsP virulence locus, which shares a long intergenic region with the divergently transcribed ospZ gene (1535 bp from TSS to TSS). Prior to this work, two discrete H-NS binding regions had …
Functional Similarity Of Prd-Containing Virulence Regulators In Bacillus Anthracis, Malik Raynor
Functional Similarity Of Prd-Containing Virulence Regulators In Bacillus Anthracis, Malik Raynor
Dissertations & Theses (Open Access)
Bacillus anthracis produces three regulators, AtxA, AcpA, and AcpB, that control virulence gene expression and are members of an emerging class of regulators termed “PCVRs” (Phosphoenolpyruvate-dependent phosphotransferase regulation Domain-Containing Virulence Regulators). AtxA controls expression of the toxin genes; lef, cya, and pag, and is the master virulence regulator and archetype PCVR. AcpA and AcpB are less well studied. AcpA and AcpB independently positively control transcription of the capsule biosynthetic operon capBCADE, and culture conditions that enhance AtxA activity result in capBCADE transcription in strains lacking acpA and acpB. RNA-Seq was used to assess the regulons of the …
The Characterization Of The Transcription Factor Msab And Its Role In Staphylococcal Virulence, Justin Batte
The Characterization Of The Transcription Factor Msab And Its Role In Staphylococcal Virulence, Justin Batte
Dissertations
Staphylococcus aureus is a common human pathogen that is responsible for a wide range of infections, ranging from relative minor skin infections to life-threatening disease such as bacteremia, septicemia, and endocarditis. S. aureus possesses many different virulent factors that aid in its ability to cause this wide array of infections. One major virulence factor includes the production of capsular polysaccharide (CP). The production of CP plays a major role in the virulence response during infection specifically by providing S. aureus an antiphagocytic mechanism that allows the pathogen to evade phagocytosis during an infection. S. aureus has developed complex genetic regulatory …
Role Of Incompatibility Group 1 (Inci1) Plasmid-Encoded Factors On Salmonella Enterica Antimicrobial Resistance And Virulence, Pravin Raghunath Kaldhone
Role Of Incompatibility Group 1 (Inci1) Plasmid-Encoded Factors On Salmonella Enterica Antimicrobial Resistance And Virulence, Pravin Raghunath Kaldhone
Graduate Theses and Dissertations
Foodborne illnesses are a leading cause of infectious diseases in the world. Among enteric organisms Salmonella is a key pathogen. It’s high prevalence in poultry and other food-animal sources make it imperative to study. Salmonella has the ability to modify its genetic content with help of mobile genetic elements such as plasmids. Incompatibiltiy group 1 (IncI1) plasmids are commonly reported in Salmonella. This study evaluates role on IncI1 plasmids in antimicrobial resistance and virulence in Salmonella. Genetic determinants of resistance and virulence are noted among our IncI1-containing Salmonella isolates. These genetic elements are also transferable and reported to carry respective …
Global Regulator Of Virulence A (Grva) Coordinates Expression Of Discrete Pathogenic Mechanisms In Enterohemorrhagic Escherichia Coli Through Interactions With Gadw-Gade, Jason K. Morgan, Ronan K. Carroll, Carly M. Harro, Khoury W Vendura, Lindsey N. Shaw, James T. Riordan
Global Regulator Of Virulence A (Grva) Coordinates Expression Of Discrete Pathogenic Mechanisms In Enterohemorrhagic Escherichia Coli Through Interactions With Gadw-Gade, Jason K. Morgan, Ronan K. Carroll, Carly M. Harro, Khoury W Vendura, Lindsey N. Shaw, James T. Riordan
Molecular Biosciences Faculty Publications
UNLABELLED: Global regulator of virulence A (GrvA) is a ToxR-family transcriptional regulator that activates locus of enterocyte effacement (LEE)-dependent adherence in enterohemorrhagic Escherichia coli (EHEC). LEE activation by GrvA requires the Rcs phosphorelay response regulator RcsB and is sensitive to physiologically relevant concentrations of bicarbonate, a known stimulant of virulence systems in intestinal pathogens. This study determines the genomic scale of GrvA-dependent regulation and uncovers details of the molecular mechanism underlying GrvA-dependent regulation of pathogenic mechanisms in EHEC. In a grvA-null background of EHEC strain TW14359, RNA sequencing analysis revealed the altered expression of over 700 genes, including the downregulation …
Biophysical Properties Of Cellular Membranes In Gram-Positive Bacterial Pathogens And Their Impact On Major Physiological Attributes And Virulence Determinants, Suranjana Sen
Theses and Dissertations
The cytoplasmic membrane of bacterial cells, forming an essential barrier from the surroundings, is a critical component of cellular physiology ensuring proper survival and maintenance of major cellular functions. The integrity of the membrane is an important feature that plays an essential role in the transport of solutes and nutrients through active and passive pathways, functions of membrane-associated proteins, electron transport and ATP synthesis, maintaining turgor pressure and combating environmental stresses, and thus is a crucial factor of a majority of cellular adaptations. The various biophysical properties affecting the integrity of this membrane are mainly determined by the composition and …
Genetic Basis For The Virulence Of Enterohemorrhagic Escherichia Coli Strain Tw14359, Jason Kyle Morgan
Genetic Basis For The Virulence Of Enterohemorrhagic Escherichia Coli Strain Tw14359, Jason Kyle Morgan
USF Tampa Graduate Theses and Dissertations
Enterohemorrhagic Escherichia coli (EHEC) is a virulent pathotype of E. coli that is associated with major outbreaks of hemorrhagic colitis and the life-threatening kidney disease hemolytic uremic syndrome. For successful host colonization and attachment to the intestinal mucosa, EHEC requires the locus of enterocyte effacement (LEE) pathogenicity island, which encodes a type III secretion system (TTSS) responsible for secreting and translocating effector proteins into host colonocytes. Regulation of the LEE is primarily directed through the first operon, LEE1, encoding the locus encoded regulator (Ler), and occurs through the direct and indirect action of several regulators. The 2006 U.S. spinach outbreak …
The Impact Of Environment On Virulence Of The Pathogenic Yeast Cryptococcus Gattii, Deborah Jean Springer
The Impact Of Environment On Virulence Of The Pathogenic Yeast Cryptococcus Gattii, Deborah Jean Springer
Legacy Theses & Dissertations (2009 - 2024)
Four serotypes of Cryptococcus are responsible for most human and animal infections. C. gattii , serotype B and C, are the primary the causative agent of cryptococcosis in immune competent individuals whilst, C. neoformans var. neoformans serotype D, and C. neoformans var. grubii serotype A are most prevalent in immunocompromised hosts world-wide. C. gattii is recognized as a species distinct from C. neoformans based on differences in clinical manifestations, morphology, biological characteristics, and environmental niche. We used the plant model Arabidopsis thaliana plants and plant derived substrates as a model to explore C. gattii interactions in its ecological niche. C. …
Serotype Association And Regulation Of The Hyaluronate Lyase Gene Of Streptococcus Pyogenes, Martha Stokes
Serotype Association And Regulation Of The Hyaluronate Lyase Gene Of Streptococcus Pyogenes, Martha Stokes
Theses and Dissertations in Biomedical Sciences
S. pyogenes expresses many virulence factors, controlled by a complex regulatory network. These include hyaluronate lyase, an enzyme that degrades hyaluronic acid, a major component of the human extracellular matrix. Paradoxically, hyaluronic acid is also the sole component of the bacterium's capsule, a primary defense against the host immune response. The hylA gene, which encodes the enzyme, has been shown to take three structural forms: a full-length gene, one containing a 3' deletion and a gene that produces a prematurely truncated protein. This work was intended to show that the structure of hylA is associated with serotype, and …