Microbiology Commons^™

A Novel Binding Interaction For The Paxillin Ld3 Motif: Paxillin Ld3 Mediates Merlin-Paxillin Binding At Paxillin Binding Domain 1, Sandra E. Beattie Geden

Electronic Theses and Dissertations

Neurofibromatosis type 2, an autosomal dominant genetic disorder, causes predisposed individuals to develop various benign central and peripheral nervous system tumors. The characteristic tumors of this disease are schwannomas, which are tumors of the Schwann cells, typically on the vestibular nerve. These and the other associated tumors slowly compress nervous system structures causing deafness and loss of balance, resulting in an average life-span of less than 40 years. The product of the Nf2 gene is the protein named merlin or schwannomin. In individuals diagnosed with NF2, merlin is either absent or mutated to the point of inactivation. As such, merlin …

Enterotoxin B Subunit Lectins As Adjuvants For Improvement Of Mucosal Vaccine, Nak-Won Choi

Loma Linda University Electronic Theses, Dissertations & Projects

In comparison with whole organism vaccines, subunit vaccines may be safer for immunization but may lack sufficient immunogenicity to provide complete immunity to the pathogen. To resolve this problem, bacterial and plant enterotoxin B subunit adjuvants containing a variety of receptor-binding properties were used to enhance the immunogenicity of rotavirus subunit vaccines. Enterotoxin B subunit adjuvants were employed to enhance protection against virus infection. Pentameric cholera toxin B subunit (CTB), shiga toxin-1 B subunit (STB) and monomeric ricin toxin B subunit (RTB) molecules were genetically linked to a 90 amino acid peptide from the simian rotavirus (SA11) nonstructural protein NSP4 …

Cloning And Functional Analysis Of The Putative Tetracycline Resistance Gene Hp1165 In Helicobacter Pylori, Yuhuan Li

All-Inclusive List of Electronic Theses and Dissertations

Tetracycline has been used in combination with other antibiotics in treatment of Helicobacter pylori infection. However, tetracycline resistance has developed in clinical isolates of H. pylori, rendering treatment failure. Mutations in the 16S rRNA gene have been reported to mediate tetracycline resistance in some patient isolates. Nevertheless, the diversity of tetracycline resistance cases suggests multiple genes are involved. HPl 165, a putative tetracycline resistance gene in the genome of H. pylori 26695, displays 49.8% identity to the tetracycline efflux gene tetA (P) from Clostridium perfringens. To determine the function of the HPl 165 gene and gain a better understanding of …

Pcr And 16s Rdna Sequencing For Identifying And Comparing Gram-Negative Bacteria, Molly Truax

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Extracullular Atp Regulates Il-1beta Release From Microglial Cells Via Purinergic Receptor After In Vitro Trauma, Chengya Liang

Electronic Theses and Dissertations

Traumatic brain injury (TBI) induces a state of microglialactivation, which includes upregulation of macrophage functions and release inflammatory mediators such as certain inflammatory cytokines. Current literature suggests that interleukin-1Beta is an important cytokine mediator, which is dramatically increased after brain injury. Previous studies indicate that ATP is released by traumatically injured astrocytes and serves as a cell-to-cell mediator through purinergic receptors after in vitro injury. However, the mechanism of interleukin-1Beta release after traumatic brain injury remains poorly defined and is difficult to study using in vivo models. Using an in vitro model for traumatic brain injury (cell strain or stretch), …

Survival Of Mycobacterium Avium Subspecies Paratuberculosis In The Pol, John Rumsey

Electronic Theses and Dissertations

Mycobacterium avium subspecies paratuberculosis (map) is an intracellular pathogen that is known to parasitize macrophages and monocytes. Map infiltrates gastrointestinal tract host tissue where it is the known etiological agent of johne's disease in ruminants and implicated in the etiology of crohn's disease in humans. Map's ability to survive within macrophages enables it to disseminate throughout the rest of the host, possibly infecting other circulating blood leukocytes. In this study, the survival and fate of map strain atcc 43015 (human isolate) following phagocytosis was determined using in vitro murine macrophage cell line j774a.1 and polymorphonuclear cells (pmnc's) from five crohn's …

Dissecting The Loci Of Low-Level Quinine Resistance In Malaria Parasites, Michael T. Ferdig, Roland A. Cooper, Jianbing Mu, Bingbing Deng, Deirdre A. Joy, Xin-Zhuan Su, Thomas E. Wellems

Biological Sciences Faculty Publications

Quinine (QN) remains effective against Plasmodium falciparum, but its decreasing efficacy is documented from different continents. Multiple genes are likely to contribute to the evolution of QN resistance. To locate genes contributing to QN response variation, we have searched a P. falciparum genetic cross for quantitative trait loci (QTL). Results identify additive QTL in segments of chromosomes (Chrs) 13, 7 and 5, and pairwise effects from two additional loci of Chrs 9 and 6 that interact, respectively, with the QTL of Chrs 13 and 7. The mapped segments of Chrs 7 and 5 contain pfcrt, the determinant of …

Evaluation Of Immunogenicity Of Transgenic Chloroplast Derived Protect, Vijay Koya

Electronic Theses and Dissertations

Anthrax, a fatal bacterial infection is caused by Bacillus anthracis, a gram-positive, spore forming, capsulated, rod shaped organism. Centers for Disease Control (CDC) lists anthrax as Category A biological agent due to its severity of impact on human health, high mortality rate, acuteness of the disease and potential for delivery as a biological weapon. The currently available human vaccine in the United States (AVA anthrax vaccine adsorbed) is prepared from Alum adsorbed formalin treated supernatant culture of toxigenic, non-encapsulated strain of Bacillus anthracis with the principle component being protective antigen (PA83). Evaluation of anthrax vaccine given to nearly 400,000 US …

Cellular Immune Response And Gene Expression Profiling In Crohn's Dise, Claudia Romero

Electronic Theses and Dissertations

Despite the chronic debate in the etiology of crohn's disease (cd), a debilitating inflammatory bowel disease (ibd) closely related to ulcerative colitis (uc), an emerging interest in a possible mycobacterial role has been marked. Granuloma and pathologic manifestations in cd resemble aspects found in tuberculosis, leprosy and paratuberculosis. The latter, a chronic enteritis in cattle, goat, sheep and primates, which is similar to human enteritis, also known as cd, is caused by a fastidious, slow growing mycobacterium avium subspecies paratuberculosis (map). Due to the similarities between cd and paratuberculosis, a mycobacterial cause in cd has been proposed. Recent discovery of …

Hyaluronate Lyase Gene Of Streptococcus Pyogenes: Molecular Characterization And Regulation, Sheryl Lynne Walton

Theses and Dissertations in Biomedical Sciences

Streptococcus pyogenes causes an assortment of diseases ranging from pharyngitis to necrotizing fasciitis. This bacterium has the ability to elaborate several extracellular products capable of causing tissue damage; one of which is a hyaluronate lyase. Little information is available regarding the regulation of streptococcal hyaluronidase. As such, the expression of hylA in the hyaluronate lyase-producing strain ATCC 10403 and in strains that do not produce detectable enzyme was analyzed by RT-PCR and quantitative PCR. Hyaluronate lyase transcript was detected throughout growth for all strains; however, expression of hylA in the enzymatically inactive strains, 71698 and SF370, was determined …

Real-Time Study Of Multidrug Resistance Mechanism In Pseudomonas Aeruginosa Using Nanoparticle Optics And Single Live Cell Imaging, Sophia Vasou Kyriacou

Chemistry & Biochemistry Theses & Dissertations

This thesis centers on the study of the xenobiotic efflux system in Pseudomonas aeruginosa, which is a ubiquitous bacterium. It resists many structurally and functionally diverse substrates due to expression of Mex-extrusion pumps, including MexAB-OprM, MexCD-OprJ, MexEF-OprN and MexXY-OprM systems. Despite extensive research, the structure and mechanism of multidrug resistance is unclear (1-9). For example, (i) how do MexA, MexB and OprM proteins assemble to extrude antibiotics? (ii) What is the antibiotic susceptibility of MexA, MexB, and OprM proteins? (iii) How do substrates cross the outer membrane of P. aeruginosa? (iv) Where are antibiotics accumulated inside the cell? This thesis …

Multiple Transporters Associated With Malaria Parasite Responses To Chloroquine And Quinine, Jianbing Mu, Michael T. Ferdig, Xiaorong Feng, Deirdre A. Joy, Junhui Duan, Tetsuya Furuya, G. Subramanian, L. Aravind, Roland A. Cooper, John C. Wootton, Momia Xiong, Xin-Zhuan Su

Biological Sciences Faculty Publications

Mutations and/or overexpression of various transporters are known to confer drug resistance in a variety of organisms. In the malaria parasite Plasmodium falciparum, a homologue of P-glycoprotein, PfMDR1, has been implicated in responses to chloroquine (CO), quinine (ON) and other drugs, and a putative transporter, PfCRT, was recently demonstrated to be the key molecule in CO resistance. However, other unknown molecules are probably involved, as different parasite clones carrying the same pfcrt and pfmdr1 alleles show a wide range of quantitative responses to CO and ON. Such molecules may contribute to increasing incidences of ON treatment failure, the molecular basis …

Evidence For An Epigenetic Mechanism By Which Hsp90 Acts As A Capacitor For Morphological Evolution, Vincent E. Sollars, Xiangyi Lu, Li Xiao, Xiaoyan Wang, Mark D. Garfinkel, Douglas M. Ruden

Biochemistry and Microbiology

Morphological alterations have been shown to occur in Drosophila melanogaster when function of Hsp90 (heat shock 0-kDa protein 1α, encoded by Hsp83) is compromised during development1. Genetic selection maintains the altered phenotypes in subsequent generations1. Recent experiments have shown, however, that phenotypic variation still occurs in nearly isogenic recombinant inbred strains of Arabidopsis thaliana2. Using a sensitized isogenic D. melanogaster strain, iso-KrIf-1, we confirm this finding and present evidence supporting an epigenetic mechanism for Hsp90’s capacitor function, whereby reduced activity of Hsp90 induces a heritably altered chromatin state. The altered chromatin state is evidenced by ectopic expression …

The Deadly Trypanosome: Understanding The Parasite That Causes Sleeping Sickness, Patricia E. Mancini

Bridgewater Review

No abstract provided.

Comparison Of Tnf-A Levels Produced By Macrophages Treated With Brucella Abortus And Escherichia Coli Lps, Tajie Harris

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Murine Epidermal Cell Antigen (Skn)-Directed Autoimmunity Induced By Transfer Of Cd4+ T Cells, Susan H. Jackman, Shivaleela Keerthy, Giselle Perry

Biochemistry and Microbiology

While pathogenic T cells have been identified for several diseases with epithelial cell damage, an autoimmune T cell-mediated response targeted against a known keratinocyte antigen has not been reported. Previously we described an autoimmune response directed to the mouse epidermal cell antigens, Skn. For our murine model, primed Skn-immune lymphocytes are adoptively transferred to recipients, which develop lesions at the site of mild skin trauma. In this study we investigated the nature of the autoimmune component of the Skn response. A time-course study demonstrated a relationship between the number of primed Sknimmune cells injected and the severity of skin lesions …

Serotyping Group B Streptococci In A Small Community Hospital: An Analysis Of Distribution And Site Of Isolation, Jennifer M. Smith, Jason A. Rexroth, David G. Chaffin, Susan H. Jackman

Biochemistry and Microbiology

Objective: To determine the prevalence and site of isolation of different serotypes of group B streptococcus (GBS) colonization or infection at a small community hospital.

Methods: GBS isolates were obtained from a small community hospital and were then serotyped as la, Ib, II, III, IV, V or non-typeable. Hospital records were reviewed for patient sex, age and pregnancy status as well as the site of GBS isolation.

Results: GBS serotypes Ia, III and V were most common and accounted for over 60% of the total number of isolates. Serotype Ia was most prevalent in reproductive-age females, while serotypes V and …

Aerobic Biodegradation Of Methyl Tert-Butyl Ether By Aquifer Bacteria From Leaking Underground Storage Tank Sites, S. R. Kane, H. R. Beller, T. C. Legler, C. J. Koester, Holly C. Pinkart, R. U. Halden, A. M. Happel

All Faculty Scholarship for the College of the Sciences

The potential for aerobic methyl tert-butyl ether (MTBE) degradation was investigated with microcosms containing aquifer sediment and groundwater from four MTBE-contaminated sites characterized by oxygen-limited in situ conditions. MTBE depletion was observed for sediments from two sites (e.g., 4.5 mg/liter degraded in 15 days after a 4-day lag period), whereas no consumption of MTBE was observed for sediments from the other sites after 75 days. For sediments in which MTBE was consumed, 43 to 54% of added [U-¹⁴C]MTBE was mineralized to¹⁴CO₂. Molecular phylogenetic analyses of these sediments indicated the enrichment of species closely …

Interactions Among Murine Cytomegalovirus Us22 Family Gene Products That Influence Viral Pathogenesis, Zaruhi Karabekian

Theses and Dissertations in Biomedical Sciences

Cytomegalovirus (CMV) is a complex, ubiquitous herpesvirus that is characterized by acute, chronic, and latent infections. Monocytes-macrophages are the key target cell type involved in pathogenesis, which is most effectively studied using the murine model of CMV infection. Previously three murine CMV (MCMV) genes (M139, M140, and M141) were identified to regulate viral expression in cultured macrophages and in mice. These genes are members of the US22 gene family with respect to HCMV homology. There is no function assigned to the proteins encoded by these genes. However, deletion of M139, M140, and M141 significantly curtails growth of MCMV in macrophages …

Nuclear Export Of 60s Ribosomal Subunits Depends On Xpo1p And Requires A Nuclear Export Sequence-Containing Factor, Nmd3p, That Associates With The Large Subunit Protein Rpl10p, Olivier Gadal, Daniela Strau, Jacques Kessl, Bernard Trumpower

Dartmouth Scholarship

Nuclear export of ribosomes requires a subset of nucleoporins and the Ran system, but specific transport factors have not been identified. Using a large subunit reporter (Rpl25p-eGFP), we have isolated several temperature-sensitive ribosomal export (rix) mutants. One of these corresponds to the ribosomal protein Rpl10p, which interacts directly with Nmd3p, a conserved and essential protein associated with 60S subunits. We find that thermosensitive nmd3 mutants are impaired in large subunit export. Strikingly, Nmd3p shuttles between the nucleus and cytoplasm and is exported by the nuclear export receptor Xpo1p. Moreover, we show that export of 60S subunits is Xpo1p dependent. We …

Characterization Of The Human Cytomegalovirus Ul75 Late Gene Promoter, Bernard J. P. Mcwatters

Theses and Dissertations in Biomedical Sciences

Gene expression during productive infection by the human cytomegalovirus (HCMV) occurs in an ordered and sequential manner, beginning with immediate early (IE), then early (E) and finally late (L) gene expression. Significant work has addressed the regulation of IE and E gene expression while relatively little work has addressed the control of late gene expression. In order to further address HCMV late gene expression, the promoter of the HCMV UL75 (glycoprotein H, gH) late gene was characterized. The data obtained in this study were combined with observations made in two other studies that have addressed HCMV late gene expression to …

Characterization Of 50s Ribosomal Subunit Assembly Inhibition In Erythromycin Treated Escherichia Coli Cells., Jerry Edward Usary

Electronic Theses and Dissertations

Erythromycin has long been recognized for its ability to inhibit protein synthesis by interfering with mRNA translation on the bacterial ribosome. We have recently shown that erythromycin also inhibits the assembly of the 50S ribosomal subunit in growing bacterial cells. The nature of this assembly inhibition has been investigated using ³H-uridine pulse-chase labeling of control and erythromycin treated E. coli cells.

Subunit assembly was examined by sucrose gradient centrifugation of labeled cell lysates. Normal assembly kinetics of subunit assembly were observed in control cells at 37°C. Formation of the 30S subunit was completed by 7.5 minutes and assembly of …

Molecular Evolution Of Insecticidal Spore-Forming Bacteria, John Pool

Honors Theses

Molecular methods are increasingly being used to determine the phylogeny of microorganisms. This research was intended to determine phylogenetic relationships for bacteria of the species Bacillus thuringiensis and other members of the Bacillus cereus group. Each strain was analyzed by its sasp-B gene sequence to determine its species classification and relation to other strains studied. Results of this study indicated that according to the sasp-B gene tree, the species Bacillus thuringiensis is a paraphyletic with respect to both Bacillus cereus and Bacillus anthracis. Some unexpected results and implications for species designations are also discussed.

A Study On The Effects Of The N-Terminal Amino Acid Sequence On The Activation Of Human T-Cell Leukemia Virus Type 1 Protease, Hidayah Muhammad Kendall

Chemistry & Biochemistry Theses & Dissertations

Human T-cell leukemia virus type 1 (HTL V-1) is dependent upon the enzymatic activity of its protease for maturation. Maturation of the protease is facilitated by cleavage of specific amino acid residues, followed by dimerization. The effects of the amino acid sequence located N-terminally to the cleavage site on the ability of the protease to become active were the focus of the current study. These amino acid sequences were contributed by the plasmid vector into which the protease gene was inserted.

Surface probability analyses (SPAs) of the vectors, as well as for native sequences which produce the mature protease and …

Relationship Between Udp-Glucose 4-Epimerase Activity And Oligoglucose Glycoforms In Two Strains Of Neisseria Meningitidis, F K. Lee, B W. Gibson, William Melaugh, A Zaleski, M A. Apicella

Chemistry Faculty Publications

Sodium dodecyl sulfate-polyacrylamide gel analysis of lipooligosaccharide (LOS) from Neisseria meningitidis has demonstrated considerable microheterogeneity in the variable region of LOS due to the presence of novel glycoforms. As a step toward understanding the basis for the expression of these novel glycoforms, we have examined the LOS structures and UDP-glucose 4-epimerase (epimerase) activity levels in two strains (NMB and MA-1) and their respective galE mutants. Strain NMB was found to have low epimerase activity and to contain multiple glycoforms, some of which appear to contain only glucose sugars. The galE mutant had only the oligoglucose glycoforms. Strain MA-1 had higher …

Carmoviruses (Tombusviridae), Feng Qu, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

Carmovirus is one of two officially recognized genera of Tombusviridae. Members of Tombusviridae all have icosahedral virions of about 30 nm in diameter with T = 3 symmetry that consists of 180 coat protein (CP) subunits of about 38- 43 kDa and a single-stranded (ss) RNA genome ranging in size from 4.0 to 4.7 kb. Carmoviruses share recognizable sequence similarity in both the polymerase and structural genes with members of the other genus, Tombusvirus. Sequence comparisons and phylogenetic analysis of these genes support the view that the genera are distinct but closely related. In addition, the genome organization of the …

Construction Of An Escherichia Coli Lac Repressor-Based System To Study Human Cytomegalovirus Gene Expression, Laura Fernanda Cageao-Luchetti

Theses and Dissertations in Biomedical Sciences

An Escherichia coli lac repressor-based system was developed to study the roles of human cytomegalovirus (HCMV) genes during viral replication. To this end, a recombinant HCMV expressing the lac repressor was generated (RVlac), and an HCMV-specific promoter was targeted for conditional expression by inserting the lac operator sequence. The promoter of a nonessential gene was chosen in order to be able to assess parameters of repression and derepression of the operator-containing promoter in the endogenous locus, without having virus growth dependent on the specific inducer isopropylthiogalactoside (IPTG). The feasibility of this approach to conditionally express an HCMV promoter …

Identification Of The Adp-L-Glycero-D-Manno-Heptose-6-Epimerase (Rfad) And Heptosyltransferase Ii (Rfaf) Biosynthesis Genes From Nontypeable Haemophilus Influenzae 2019, W A. Nichols, B W. Gibson, William Melaugh, N G. Lee, M Sunshine, M A. Apicella

Chemistry Faculty Publications

Haemophilus influenzae is an important human pathogen. The lipooligosaccharide (LOS) of H. influenzae has been implicated as a virulence determinant. To better understand the assembly of LOS in nontypeable H. influenzae (NtHi), we have cloned and characterized the rfaD and rfaF genes of NtHi 2019, which encode the ADP-L-glycero-D-manno-heptose-6-epimerase and heptosyltransferase II enzymes, respectively. This cloning was accomplished by the complementation of Salmonella typhimurium lipopolysaccharide (LPS) biosynthesis gene mutants. These deep rough mutants are novobiocin susceptible until complemented with the appropriate gene. In this manner, we are able to use novobiocin resistance to select for specific NtHi LOS inner core …

Characterization Of A Transposon Tn916-Generated Mutant Of Haemophilus Ducreyi 35000 Defective In Lipooligosaccharide Biosynthesis, B W. Gibson, A A. Campagnari, William Melaugh, M A. Apicella, S Grass, Jing Wang, Katherine L. Palmer, R S. Munson

Chemistry Faculty Publications

To define the role of the surface lipooligosaccharide (LOS) of Haemophilus ducreyi in the pathogenesis of chancroid, Tn916 mutants of H. ducreyi 35000 defective in expression of the murine monoclonal antibody (MAb) 3F11 epitope on H. ducreyi LOS were identified by immunologic screening. One mutant, designated 1381, has an LOS which lacks the MAb 3F11 epitope and migrates with an increased mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The gene disrupted by the Tn916 element in strain 1381 was identified by cloning the sequences flanking the Tn916 element. The sequences were then used to probe a lambda DASHII genomic library. …

A Truncated Form Of The Pho80 Cyclin Of Saccharomyces Cerevisiae Induces Expression Of A Small Cytosolic Factor Which Inhibits Vacuole Inheritance., Teresa Nicolson, Barbara Conradt, William Wickner

Dartmouth Scholarship

Vacuoles project streams of vesicles and membranous tubules into the yeast bud where they fuse, founding the daughter cell organelle, vac5-1, which encodes a truncated form of the Pho80 cyclin, inhibits normal vacuole inheritance. An in vitro inheritance assay which measures the fusion of vacuoles serves as a model for several steps of this process. We find that cytosol isolated from the vac5-1 mutant is unable to promote the fusion of wild-type vacuoles in the in vitro assay. Wild-type vacuoles are irreversibly inactivated in a time- and temperature-dependent manner if preincubated with vac5-1 cytosol and ATP, suggesting the presence of …