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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Microbial Ecology Of South Florida Surface Waters: Examining The Potential For Anthropogenic Influences, Chase P. Donnelly Aug 2018

Microbial Ecology Of South Florida Surface Waters: Examining The Potential For Anthropogenic Influences, Chase P. Donnelly

HCNSO Student Theses and Dissertations

South Florida contains one of the largest subtropical wetlands in the world, and yet not much is known about the microbes that live in these surface waters. These microbes play an important role in chemical cycling and maintaining good water quality for both human and ecosystem health. The hydrology of Florida’s surface waters is tightly regulated with the use of canal and levee systems run by the US Army Corps of Engineers and The South Florida Water Management District. These canals run through the Everglades, agriculture, and urban environments to control water levels in Lake Okeechobee, the Water Conservation ...


Functional Similarity Of Prd-Containing Virulence Regulators In Bacillus Anthracis, Malik Raynor May 2018

Functional Similarity Of Prd-Containing Virulence Regulators In Bacillus Anthracis, Malik Raynor

UT GSBS Dissertations and 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 paralogs in strains ...


Characterization Of A Putative Hemolysin Expressed By Sneathia Amnii, A Preterm Birth-Associated Pathogen, Lizette Carrasco, Kimberly Jefferson Jan 2017

Characterization Of A Putative Hemolysin Expressed By Sneathia Amnii, A Preterm Birth-Associated Pathogen, Lizette Carrasco, Kimberly Jefferson

Undergraduate Research Posters

The gram-negative bacteria Sneathia amnii is a poorly-characterized commensal of the female urogenital tract frequently associated with adverse clinical outcomes such as bacterial vaginosis (BV), amnionitis, and preterm labor. To investigate its potential role in virulence, we sought to identify and characterize virulence determinants produced by S. amnii in an effort to better understand the pathogenesis of infectious preterm birth. Through sequencing of the Sn35 genome (type strain of S. amnii), we identified two genes with amino acid sequence similarity and structural similarity to the filamentous hemagglutinin (FHA) protein of Bordetella pertussis and its Type Vb transporter. Because S. amnii ...


Protective Effects Of Pigmentation In Pseudomonas Aeruginosa: Insights On Pyomelanin Production And Inhibition By Ntbc, Laura Marie Ketelboeter May 2016

Protective Effects Of Pigmentation In Pseudomonas Aeruginosa: Insights On Pyomelanin Production And Inhibition By Ntbc, Laura Marie Ketelboeter

Theses and Dissertations

Pyomelanin is an extracellular, reddish-brown pigment produced by several environmental and pathogenic bacteria and fungi. It is derived from the phenylalanine/tyrosine catabolism pathway and is produced when homogentisate (HGA) is secreted from the cell, auto-oxidized, and self-polymerized. Point mutations or chromosomal deletions in hmgA, which encodes homogentisate 1,2-dioxygenase, result in the accumulation of HGA and subsequent pyomelanin production. My work showed that the pyomelanogenic Pseudomonas aeruginosa clinical isolate PA1111 had a chromosomal deletion of hmgA, while a second pyomelanogenic clinical isolate, DKN343, had a loss of function mutation in HmgA. The 4-hydroxyphenylpyruvate dioxygenase (Hpd) inhibiting compound 2-(2-nitro-4-trifluoromethylbenzoyl ...


The Effect Of Transformed Escherichia Coli On The Mouse Intestine Microbiome: The Microbial Metabolic Enhancement Hypothesis, Bryar P. Kader May 2016

The Effect Of Transformed Escherichia Coli On The Mouse Intestine Microbiome: The Microbial Metabolic Enhancement Hypothesis, Bryar P. Kader

Senior Honors Theses

Metabolic disorders affect around thirty-four percent of the population in the United States. Among these disorders is lactose intolerance, which results from diminished production of the human lactase enzyme. This disorder and others like it are genetically determined and cannot be cured. However, the use of transformed bacteria implanted in the colon may provide a means by which the faulty pathway can be bypassed. To test whether transformed bacteria have the capability to aid in the digestion of normally indigestible compounds, a transformed strain of Escherichia coli overexpressing the beta-galactosidase enzyme encoded by the lacZ gene was colonized in the ...


Differences In Fecal Metabolite Profiles From Geographically Distinct Populations Of Adolescents, Jessica Moncivaiz Jan 2015

Differences In Fecal Metabolite Profiles From Geographically Distinct Populations Of Adolescents, Jessica Moncivaiz

Browse all Theses and Dissertations

Microbiota of the gastrointestinal tract have a variety of functions within the human body. They participate in protection of the host from pathogens, aid in immune system development and regulation, and carry out a variety of metabolic functions. This study focuses on the ability of gut microbiota to create metabolites through the degradation of food products. Using 1H NMR on fecal water extracts, I compared the metabolite profiles of two geographically distinct cohorts: healthy adolescents from Egypt (n=28) and healthy adolescents from the United States (n=14). Multivariate statistical analyses of binned NMR data confirmed that samples separated into ...


Engineering Cry4aa For Toxicity Against The Soybean Aphid, Aphis Glycines Matsumura, Benjamin Robert Deist Jan 2015

Engineering Cry4aa For Toxicity Against The Soybean Aphid, Aphis Glycines Matsumura, Benjamin Robert Deist

Graduate Theses and Dissertations

Soybean aphid poses a significant threat to soybean agriculture in North America. Current management strategies are heavily dependent on chemical insecticides, which while presently effective, may have negative side effects. Bt toxins have been successfully used in various transgenic crops for almost 20 years to manage lepidopteran and coleopteran pests. However, this strategy has not been used in the management of aphids and other hemipterans due to their low susceptibility to Bt toxins, potentially arising from a lack of binding to the hemipteran gut. To circumvent this limitation in soybean aphids, a phage display library was screened in vivo against ...


Transcriptional Regulation Of Sinorhizobium Meliloti Cell Cycle-Related Genes In The Δcbra Mutant And Root Nodules Of Medicago Sativa, Corey S. Hazekamp Aug 2014

Transcriptional Regulation Of Sinorhizobium Meliloti Cell Cycle-Related Genes In The Δcbra Mutant And Root Nodules Of Medicago Sativa, Corey S. Hazekamp

Graduate Masters Theses

Sinorhizobium meliloti is a Gram-negative alphaproteobacterium and nitrogen-fixing symbiont, which undergoes a novel cell cycle modification during its' host-microbe interaction. I intend to monitor the transcriptional regulation of cell cycle-related genes during free-loving growth, in addition to monitoring their expression during symbiosis. Using genes known to be regulated by CtrA in C. crescentus or predicted to be regulated by CtrA in S. meliloti, I aim to show how certain cell cycle genes are regulated in S. meliloti. In C. crescentus, CtrA acts as a transcription factor that is active when phosphorylated and inactive when not phosphorylated. In S. meliloti, CbrA ...


Modification Of The Bt Toxin Cry4aa For Improved Toxin Processing In The Gut Of The Pea Aphid (Acyrthosiphon Pisum), Michael Allen Rausch Jan 2014

Modification Of The Bt Toxin Cry4aa For Improved Toxin Processing In The Gut Of The Pea Aphid (Acyrthosiphon Pisum), Michael Allen Rausch

Graduate Theses and Dissertations

Aphids are sap-sucking insects (order: Hemiptera) that cause extensive damage to a wide range of agricultural crops. Our goal is to produce a "designer" toxin based on naturally occurring insecticidal crystalline (Cry) toxins produced by the soil-dwelling bacterium Bacillus thuringiensis for use against the pea aphid, Acyrthosiphon pisum. On the basis that activation of the Cry4Aa protoxin could be a rate-limiting factor contributing to the relatively low aphicidal activity of this toxin, we introduced cathepsin L and cathepsin B cleavage sites into Cry4Aa for rapid activation and generation of the active toxin in the aphid gut environment. Incubation of modified ...


Divergent Mechanisms Of Interaction Of Helicobacter Pylori And Campylobacter Jejuni With Mucus And Mucins, Julie Ann Naughton, Karina Mariño, Brendan Dolan, Colm Reid, Ronan Gough, Mary Gallagher, Michelle Kilcoyne, Jared Gerlachscience,, Lokesh Joshi, Pauline Rudd, Stephen Carrington, Billy Bourke, Marguerite Clyne Aug 2013

Divergent Mechanisms Of Interaction Of Helicobacter Pylori And Campylobacter Jejuni With Mucus And Mucins, Julie Ann Naughton, Karina Mariño, Brendan Dolan, Colm Reid, Ronan Gough, Mary Gallagher, Michelle Kilcoyne, Jared Gerlachscience,, Lokesh Joshi, Pauline Rudd, Stephen Carrington, Billy Bourke, Marguerite Clyne

Articles

Helicobacter pylori and Campylobacter jejuni colonize the stomach and intestinal mucus, respectively. Using a combination of mucus-secreting cells, purified mucins, and a novel mucin microarray platform, we examined the interactions of these two organisms with mucus and mucins. H. pylori and C. jejuni bound to distinctly different mucins. C. jejuni displayed a striking tropism for chicken gastrointestinal mucins compared to mucins from other animals and preferentially bound mucins from specific avian intestinal sites (in order of descending preference: the large intestine, proximal small intestine, and cecum). H. pylori bound to a number of animal mucins, including porcine stomach mucin, but ...


Detection Of Viable Microorganisms Using Propidium Monoazide, Erik J. Mcfarland, Adrian Ponce Dr. Jan 2013

Detection Of Viable Microorganisms Using Propidium Monoazide, Erik J. Mcfarland, Adrian Ponce Dr.

STAR (STEM Teacher and Researcher) Presentations

Propidium monoazide (PMA) is a molecular tool used to assess viability of microorganisms. Currently, PMA is thought to discern viability through membrane permeability; PMA enters only membrane compromised cells, irreversibly crosslinks to theirDNAand precipitates theDNAout of solution, preventing it from being amplified during polymerase chain reaction (PCR). Using PMA on a sample of live and dead microorganisms results in only theDNAof living organisms being amplified and identified. Therefore, a comparison ofPCRresults with and without PMA allows one to determine the live fraction and total population, respectively.

Current literature provides conflicting evidence as to the effectiveness of the technique. Our research ...


Investigation Into The Mechanism Of Salicylate-Associated Genotypic Antibiotic Resistance In Staphylococcus Aureus, Nada Salah Helal Jan 2012

Investigation Into The Mechanism Of Salicylate-Associated Genotypic Antibiotic Resistance In Staphylococcus Aureus, Nada Salah Helal

Graduate Theses and Dissertations

Growth of Staphylococcus aureus with the NSAID salicylate increases phenotypic resistance (SAPAR), and the frequency at which heritable resistance occurs to various antibiotics (SAGAR). This study describes the effect of salicylate on heritable and phenotypic resistance to a set of antibiotics for laboratory and multi-drug resistant strains of S. aureus and investigates the link between resistance and SAGAR. Drug gradient plates were used to determine phenotypic resistance to antibiotics targeting DNA replication, transcription, translation and the cell wall in the presence or absence of salicylate. To measure heritable resistance, mutation frequencies were determined for each antibiotic in the presence and ...


Cell Envelope Constituents Of Pseudomonas Putida Contributing To Growth And Survival In Low-Water-Content Habitats , Martinus Franciscus Maria Van De Mortel Jan 2005

Cell Envelope Constituents Of Pseudomonas Putida Contributing To Growth And Survival In Low-Water-Content Habitats , Martinus Franciscus Maria Van De Mortel

Retrospective Theses and Dissertations

The ability of bacteria to respond to the ever changing environmental conditions they encounter requires the utilization of a broad range of colonization and survival strategies. One of the most important and probably least understood factors determining bacterial activity in terrestrial habitats is water availability. The goal of this dissertation research was to identify traits that contribute to maintaining a functional cell envelope when cells are dehydrated, which will help us to assess the scope of physiological changes necessary for growth in low-water-content habitats. The primary objective was to identify genes that are specifically regulated by dehydration (matric stress), and ...


Characterization Of The Ftsyex Operon Of Escherichia Coli , Becky Graham Jan 2002

Characterization Of The Ftsyex Operon Of Escherichia Coli , Becky Graham

Retrospective Theses and Dissertations

The ftsYEX operon of Escherichia coli historically has been described as a cluster of essential cell division genes. Filamentation temperature-sensitive (fts) designates a class of mutants that displays normal cell morphology at the permissive temperature of 30°C, but filaments and dies at the restrictive temperature of 42°C. The first gene, ftsY, is known to encode an essential component of a protein localization system first described in eukaryotes, the signal recognition particle (SRP) pathway. The function of the following genes, ftsE and ftsX, are much less understood. It has been shown that FtsE and FtsX comprise a two-component ATP-binding ...


Genetic And Molecular Characterization Of The Rev Protein Of Equine Infectious Anemia Virus , Michael Andrew Belshan Jan 1999

Genetic And Molecular Characterization Of The Rev Protein Of Equine Infectious Anemia Virus , Michael Andrew Belshan

Retrospective Theses and Dissertations

Members of the lentivirus subfamily of retroviruses are characterized as causing slow, chronic disease. Atypical of other lentiviruses, such as human immunodeficiency virus type 1, equine infectious anemia virus (EIAV) may produce a rapid, variable disease course in horses. Infected horses may undergo an, acute episode of disease involving viremia, fever, and thrombocytopenia. Following this acute period, horses may resolve to an inapparent infection or suffer a chronic period of additional cycles of viremia, fever, and thrombocytopenia. Horses which survive clinical episodes usually become inapparent carriers of the virus for life. Numerous virus and host factors contribute to the phenotypic ...


Analysis Of Viral Proteins Of Porcine Reproductive And Respiratory Syndrome Virus In Host Protection And Early Virus-Cell Interactions , Yanjin Zhang Jan 1998

Analysis Of Viral Proteins Of Porcine Reproductive And Respiratory Syndrome Virus In Host Protection And Early Virus-Cell Interactions , Yanjin Zhang

Retrospective Theses and Dissertations

The viral proteins of porcine reproductive and respiratory syndrome virus (PRRSV) were expressed in a baculovirus expression system. They were evaluated for protection of pigs against the respiratory disease and for function in virus-cell interactions. The open reading frames 2 to 6 products were confirmed to be membrane associated proteins as they were detected on the surface of viable insect cells by an immunofluorescence assay. Immunization of pigs with vaccines comprised of a combination of GP2, GP3 and GP4 or a combination of GP5, M and N proteins induced partial protection, but immunization with combination of GP5 and M proteins ...


Pou Domain Genes And The Immunoglobulin Octamer Motif In Chickens , Lynn Marie Heltemes Jan 1997

Pou Domain Genes And The Immunoglobulin Octamer Motif In Chickens , Lynn Marie Heltemes

Retrospective Theses and Dissertations

This research was undertaken to test the hypothesis that multiple POU genes exist and that POU proteins are involved in transcriptional regulation in the chicken. The POU protein Oct-2 has been hypothesized to partially regulate immunoglobulin gene expression through its interaction with the octamer motif found in the promoter of immunoglobulin genes. Transcriptional regulation of immunoglobulin genes provides a model for tissue-specific gene expression in the immune system. In searching for a chicken Oct-2 homologue, two partial chicken POU domain genes were identified. A cDNA clone encoding the POU domain of Brn-3a was isolated and showed near identity to the ...


Identification Of Genes In Tn916 Encoding Membrane-Targeted Proteins, Suganda Loe Jan 1997

Identification Of Genes In Tn916 Encoding Membrane-Targeted Proteins, Suganda Loe

Retrospective Theses and Dissertations

Tn916 is a 18 kb, broad-host range conjugative transposon originally isolated from Enterococcus faecalis. Transposon TnphoA was used to identify genes in Tn916 encoding for membrane-targeted proteins or for secretion. Sixty five independent PhoA+ gene fusions were isolated. These insertions clustered into two regions, open reading frames 13 and 15 (Flanagan et al., Plasmid 32:350-354). These TnphoA insertional mutations in resulted in a Tn+ (ability to transpose intracellularly) and Tra- (inability to transfer conjugatively) phenotype. The hydrophathy analysis of ORF13 and ORF15 revealed that these proteins lack the classical signal peptides necessary for protein export, suggesting that these two ...


Sequence And Functional Analysis Of The P97 Swine Cilium Adhesin Gene Of Mycoplasma Hyopneumoniae , Tsungda Hsu Jan 1997

Sequence And Functional Analysis Of The P97 Swine Cilium Adhesin Gene Of Mycoplasma Hyopneumoniae , Tsungda Hsu

Retrospective Theses and Dissertations

Mycoplasma hyopneumoniae causes swine enzootic pneumonia, an important disease in the swine industry. Adherence of M. hyopneumoniae to the cilia of the tracheal epithelial cells is required to establish infection. Previous studies have identified a 97-kDa protein (P97) as the putative ciliary adhesin. To further characterize the P97 protein, the gene has been cloned, its DNA sequence analyzed, and the function of the P97 protein expressed in Escherichia coli studied. These results demonstrated that recombinant P97 has swine ciliary adherence activity. Further analysis revealed that the P97 gene was translated as a 124.9-kilodalton (kDa) protein and subjected to proteolytic ...


Cloning Of Bovine Intercellular Adhesion Molecules And Characterization Of Expression Of Neutrophil Adhesion Molecules In Periparturient Cows And Calves , Eunkyung Lee Jan 1996

Cloning Of Bovine Intercellular Adhesion Molecules And Characterization Of Expression Of Neutrophil Adhesion Molecules In Periparturient Cows And Calves , Eunkyung Lee

Retrospective Theses and Dissertations

The interactions of circulating leukocytes with the endothelium represent a key point in the effector functions of the immune system by regulating the specificity and strength of cell-cell interactions. The recruitment of neutrophils to sites of inflammation is initiated by chemoattractants. The initial contact of neutrophils on vascular endothelial cells is a rolling interaction mediated by members of the selectin family. These include E-selectin and P-selectin on the surface of activated endothelial cells, and L-selectin on neutrophils. The subsequent activation of leukocyte [beta]2 integrins, which bind to the glycoprotein intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, is essential for ...


Characterization Of Membrane-Associated Nuclease Activity In Mycoplasma Pulmonis , Karalee Jean Jarvill-Taylor Jan 1996

Characterization Of Membrane-Associated Nuclease Activity In Mycoplasma Pulmonis , Karalee Jean Jarvill-Taylor

Retrospective Theses and Dissertations

Mycoplasmas are deficient in numerous biosynthetic pathways. Consequently, growth is dependent upon the acquisition of structural and macromolecular precursors from the environment. These precursors include phospholipids, fatty acids and nucleotide bases. DNases and RNases are postulated to be involved in the acquisition of nucleotides. The goals of this study were to determine if nuclease activities are universally associated with mycoplasmas, characterize the nucleases by subcellular distribution and apparent molecular weight, and to identify and analyze the nuclease gene(s) in Mycoplasma pulmonis;Nuclease activity was present in all mycoplasma species tested. The level of activity did not correlate with virulence ...


Moraxella (Branhamella) Catarrhalis: A Molecular Epidemiology Study, Lyndell R. Gill May 1995

Moraxella (Branhamella) Catarrhalis: A Molecular Epidemiology Study, Lyndell R. Gill

Electronic Theses and Dissertations

Moraxella (Branhamella) catarrhalis is the third-most-frequently isolated microorganism associated with acute exacerbations of chronic bronchitis in patients during their stay at the Mountain Home VA Medical Center (MHVAMC). In order to develop a practical, epidemiologically-meaningful typing method for M. (B.) catarrhalis, we tested two methods based on analysis of chromosomal DNA for typeability, reproducibility, and ability to differentiate between unrelated strains (discriminatory power, D). M. (B.) catarrhalis isolants from MHVAMC from 7/1/87-6/30/88 were grown overnight in broth and embedded in agarose. DNA was isolated by standard methods. The DNA was subjected to: (1) restriction endonuclease digestion ...


Genetic And Biochemical Characterization Of Brucella Abortus Strain Rb51 , Allen Elroy Jensen Jan 1995

Genetic And Biochemical Characterization Of Brucella Abortus Strain Rb51 , Allen Elroy Jensen

Retrospective Theses and Dissertations

Brucella abortus strain RB51, a naturally derived rough variant, has been proposed to replace strain 19 for use as a vaccine against brucellosis in cattle. Utilizing fingerprinting and standard biotyping techniques, it was possible to differentiate RB51 from other brucellae and to ascertain the stability of RB51. Standardization of a genomic fingerprinting procedure using restriction endonuclease profiles of total DNA from Brucella are described. Although the focus was principally on B. abortus isolates from cattle, the investigation included field isolates from bison and elk, reference strains, vaccinal strains, and genetically-engineered brucellae;Pulsed-field gel electrophoresis profiles of the reference type strains ...


Expression And Characterization Of Bovine Rotavirus Proteins In The Baculovirus System , Young Soo Lyoo Jan 1995

Expression And Characterization Of Bovine Rotavirus Proteins In The Baculovirus System , Young Soo Lyoo

Retrospective Theses and Dissertations

Recombinant proteins of bovine rotavirus VP2, VP4, VP6 and VP7 were expressed in insect cells using baculovirus expression vectors. Expressed recombinant proteins were similar to those of rotavirus. Recombinant viral antigens expressed in insect cells reacted with polyclonal antiserum to the VMRI strain of BRV by an indirect immunofluorescence test. Expressed recombinant proteins were characterized by radioimmunoprecipitation and their molecular mass was found to be similar to that of in wild type rotavirus. These four recombinant proteins were antigenic in guinea pigs and induced antibodies to the corresponding rotavirus proteins as detected by indirect immunofluorescence test. Recombinant viruses Bac.pVL ...


Compilation And Analysis Of Mycobacterium Paratuberculosis Promoters , John Patrick Bannantine Jan 1995

Compilation And Analysis Of Mycobacterium Paratuberculosis Promoters , John Patrick Bannantine

Retrospective Theses and Dissertations

Mycobacterium paratuberculosis transcriptional and translational signals were studied to gain insight into gene expression in this organism. To study M. paratuberculosis promoter structures, a more versatile promoter selection vector was constructed from the pKO1 parent vector. This new plasmid, pJJ2, was used to identify 11 promoter fragments from an M. paratuberculosis DNA library. In addition, a previously characterized M. paratuberculosis promoter, contained in a 493-bp EcoRI fragment, was cloned into the new vector to test the efficacy in cloning novel M. paratuberculosis promoters. In a related study, an expression probe shuttle plasmid (pYUB76) was employed to clone M. paratuberculosis expression ...


Identification And Characterization Of A Chicken Major Histocompatibility Complex Class Ii[Beta] Gene Promoter , Yunfei Chen Jan 1995

Identification And Characterization Of A Chicken Major Histocompatibility Complex Class Ii[Beta] Gene Promoter , Yunfei Chen

Retrospective Theses and Dissertations

The major histocompatibility complex (MHC) contains a variety of genes. Among them, the class II genes encode proteins involved in antigen presentation to helper T cells, a key step in initiating immune responses. The regulation of class II gene expression has been extensively studied in mammals. Such studies have been lacking in the avian species, despite the well-established association of the avian MHC with disease resistance and production traits. The objective of this study was to functionally analyze a putative chicken MHC class II gene promoter;Using the chloramphenicol acetyltransferase (CAT) reporter system, a functional chicken MHC class II[beta ...


Molecular Characterization Of Porcine Respiratory Coronavirus Isolates With Varying Pathogenicity , Eric Martin Vaughn Jan 1994

Molecular Characterization Of Porcine Respiratory Coronavirus Isolates With Varying Pathogenicity , Eric Martin Vaughn

Retrospective Theses and Dissertations

Three new isolates of porcine respiratory coronavirus (PRCV) were isolated and characterized. Two of the PRCV isolates, AR310 and LEPP, were shown to produce moderate interstitial pneumonia, whereas the third PRCV isolate, IA1894, was only mildly pathogenic in five-week-old specific pathogen free pigs. The previously described PRCV isolate ISU-1, a mildly pathogenic PRCV isolate, was also included in this study. These PRCV isolates with varying pathogenicity provided an opportunity to determine if there are certain genes that correlate with virulence, as the genes 3 and 3-1 have been hypothesized to be virulence determinants for transmissible gastroenteritis virus (TGEV) isolates. Using ...


Molecular Mechanisms Of Mycoplasma Hyopneumoniae Adherence To Swine Respiratory Epithelial Cells, Qijing Zhang Jan 1994

Molecular Mechanisms Of Mycoplasma Hyopneumoniae Adherence To Swine Respiratory Epithelial Cells, Qijing Zhang

Retrospective Theses and Dissertations

A microtiter plate adherence assay for Mycoplasma hyopneumoniae was established by using purified swine tracheal cilia which are the natural targets for the mycoplasma. M. hyopneumoniae bound specifically to solubilized cilia immobilized onto microtiter plates. Dextran sulfate, heparin, chondroitin sulfate, laminin, mucin, and fucoidan significantly inhibited binding of the mycoplasmas to cilia. Heparin, mucin, fucoidan, and chondroitin sulfate interacted with the adhesins on the surface of mycoplasmas, whereas laminin blocked the receptors in cilia. Treatment of cilia with neuraminidase appeared to promote adherence of the mycoplasmas; whereas, treatment of cilia with sodium metaperiodate decreased the binding. In the second study ...


Identification And Characterization Of Mycoplasma Promoters , Kevin Lee Knudtson Jan 1993

Identification And Characterization Of Mycoplasma Promoters , Kevin Lee Knudtson

Retrospective Theses and Dissertations

The development of a reporter gene system for mycoplasmas was sought to be able to examine gene regulation in mycoplasmas. Initial studies were designed to examine whether the Escherichia coli lacZ gene could be used as a reporter gene in mycoplasmas. The test system examined the ability of the Mycoplasma capricolum rrnA P2 or E. coli rrnB P1 promoters to initiate the transcription of trp[superscript]'-lacZYA in Acholeplasma ISM1499. The results showed that the M. capricolum, but not the E. coli promoter, could promote the expression of lacZ. Because the test system was based on a translational fusion that ...


Characterization Of The 31-Kda Antigen Gene Of Haemophilus Somnus And Its Product , Jonghwa Won Jan 1993

Characterization Of The 31-Kda Antigen Gene Of Haemophilus Somnus And Its Product , Jonghwa Won

Retrospective Theses and Dissertations

Consistent immunoreactivities of the 31-, 40- and 78-kDa proteins of Haemophilus somnus were observed in immunoblots with bovine antisera to H. somnus. A genomic library of H. somnus 8025 DNA was constructed in plasmid pUC19 and 45 recombinants expressed immunoreactive proteins in Western blots using bovine antiserum. Ten of the recombinants expressing a 31-kDa protein caused lysis of bovine erythrocytes. Restriction endonuclease mapping indicated that the hemolytic recombinants shared an approximately 1.7-kb BglII fragment. Southern blot analysis using the BglII fragment as a probe revealed homology among the recombinants and the presence of an identically sized BglII fragment in ...