Pathogenic Microbiology Commons^™

Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, Alexandra King, Lon Chubiz Phd, Brenda Pratte, Lauren Daugherty

Undergraduate Research Symposium

Salmonella is a relatively abundant, virulent species of bacteria that is most known for spreading gastrointestinal diseases through food. These illnesses result in approximately 1.35 million infections, including over 25,000 hospitalizations each year, in the U.S. alone (CDC.gov). As antibiotic resistance becomes an increasingly urgent public health problem, the importance of developing alternative treatment methods is only becoming more crucial. One of the genes responsible for this virulence is known as hilA. HilA is the main transcriptional regulator of Salmonella Pathogenicity Island-1 gene (UniProt). SPI-1 plays an important role in the invasion of Salmonella into epithelial cells. The proteins encoded …

Sars-Cov-2 Reveals That Chimeric Agents Are The Bioweapons Of The Future, Rachel Craig

Senior Honors Theses

Bioweapons programs have existed since their development during the Cold War. These biowarfare programs initially utilized naturally occurring pathogens capable of infecting crops, livestock populations, and human populations. Anthrax is a widely exploited bioagent responsible for attacks ranging from the Germans’ deployment in World War I to the mailing of anthrax through the postal service in attempts on U.S. senators’ lives. With the development of genetic manipulations, the Soviet Union began modifying anthrax to resist detection and treatment. With the continued advancement of science and technology, a new bioagent has entered the scene – the man-made chimeric virus. Chimeric viruses …

Repression Of Tick Microrna-133 Induces Organic Anion Transporting Polypeptide Expression Critical For Anaplasma Phagocytophilumsurvival In The Vector And Transmission To The Vertebrate Host, Ellango Ramasamy, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

The microRNAs (miRNAs) are important regulators of gene expression. In this study, we provide evidence for the first time to show that rickettsial pathogen Anaplasma phagocytophilum infection results in the down-regulation of tick microRNA-133 (miR-133), to induce Ixodes scapularis organic anion transporting polypeptide (isoatp4056) gene expression critical for this bacterial survival in the vector and for its transmission to the vertebrate host. Transfection studies with recombinant constructs containing transcriptional fusions confirmed binding of miR-133 to isoatp4056 mRNA. Treatment with miR-133 inhibitor resulted in increased bacterial burden and isoatp4056 expression in ticks and tick cells. In contrast, treatment with …

Arthropod Transcriptional Activator Protein-1 (Ap-1) Aids Tick-Rickettsial Pathogen Survival In The Cold, Supreet Khanal, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ixodes scapularis ticks transmit several pathogens to humans including rickettsial bacterium, Anaplasma phagocytophilum. Here, we report that A. phagocytophilum uses tick transcriptional activator protein-1 (AP-1) as a molecular switch in the regulation of arthropod antifreeze gene, iafgp. RNAi-mediated silencing of ap-1 expression significantly affected iafgp gene expression and A. phagocytophilum burden in ticks upon acquisition from the murine host. Gel shift assays provide evidence that both the bacterium and AP-1 influences iafgp promoter and expression. The luciferase assays revealed that a region of approximately 700 bp upstream of the antifreeze gene is sufficient for AP-1 binding to promote …

Breeding For Resistance In California Strawberry To Verticillium Dahliae, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Since 1930 the University of California, Davis, has been developing strawberry cultivars that are adapted to the agricultural industry and regional farms. Developing cultivars that require fewer inputs are of significant economic importance in agronomy. Developing a crop resistant to a disease is beneficial for horticulturists since less labor and chemicals are needed for a high yield.⁶

In commercial strawberry cultivars, complete resistance to V. dahlia is extremely rare. The majority of Californian strawberry cultivars are highly susceptible to it.² Over the last 18 years of plant breeding for strawberry cultivars with a high degree of resistance and …

Phenomenological And Molecular Basis Of The Cnidarian Immune System, Tanya Brown

FIU Electronic Theses and Dissertations

Coral reefs are one of the most diverse ecosystems on the planet due partially to the habitat structure provided by corals. Corals are long lived organisms that can live for hundreds of years and as a result growth of many species is very slow. As a result of this, recovery of corals from disease outbreaks is very slow and difficult and therefore the ecosystem is deteriorating rapidly. Due to this increase in disease and its detrimental effect on coral reefs, it has become imperative to study how corals respond to disease outbreaks. The response of the coral to pathogens is …

Non-Essentiality Of Alr And Muri Genes In Mycobacteria, Philion L. Hoff, Denise Zinniel, Raúl G. Barletta

UCARE Research Products

Amino acids are the building blocks of life. If DNA is the blueprint, amino acids are the lumber that proteins are built with. Proteins are built with left-handed, L- forms of amino acids. Bacteria have an essential cell wall component that happens to be an exception: peptidoglycan. Bacteria have enzymes called racemases that convert L- amino acid forms into right-handed, D- forms. Amino acids participate in many reactions with keto acids. Transaminases allow conversion between amino acids by transfer of an amino group.

Previous reports claimed there is no D-ala transaminase activity in mycobacteria and thus alr and murI genes …

Deletion Mutant Library For Investigation Of Functional Outputs Of Cyclic Diguanylate Metabolism In Pseudomonas Aeruginosa Pa14, Dae-Gon Ha, Megan E. Richman, George A. O'Toole

Dartmouth Scholarship

We constructed a library of in-frame deletion mutants targeting each gene in Pseudomonas aeruginosa PA14 predicted to participate in cyclic di-GMP (c-di-GMP) metabolism (biosynthesis or degradation) to provide a toolkit to assist investigators studying c-di-GMP-mediated regulation by this microbe. We present phenotypic assessments of each mutant, including biofilm formation, exopolysaccharide (EPS) production, swimming motility, swarming motility, and twitch motility, as a means to initially characterize these mutants and to demonstrate the potential utility of this library.

Ecology And Genetic Structure Of A Northern Temperate Vibrio Cholerae Population Related To Toxigenic Isolates, Brian M. Schuster, Anna L. Tyzik, Rachel A. Donner, Megan J. Striplin, Salvador Almagro-Moreno

Dartmouth Scholarship

Although Vibrio cholerae is an important human pathogen, little is known about its populations in regions where the organism is endemic but where cholera disease is rare. A total of 31 independent isolates confirmed as V. cholerae were collected from water, sediment, and oysters in 2008 and 2009 from the Great Bay Estuary (GBE) in New Hampshire, a location where the organism has never been detected. Environmental analyses suggested that abundance correlates most strongly with rainfall events, as determined from data averaged over several days prior to collection. Phenotyping, genotyping, and multilocus sequence analysis (MLSA) revealed a highly diverse endemic …

Type Ii Toxoplasma Gondii Ku80 Knockout Strains Enable Functional Analysis Of Genes Required For Cyst Development And Latent Infection, Barbara A. Fox, Alejandra Falla, Leah M. Rommereim, Tadakimi Tomita

Dartmouth Scholarship

Type II Toxoplasma gondii KU80 knockouts (Δku80) deficient in nonhomologous end joining were developed to delete the dominant pathway mediating random integration of targeting episomes. Gene targeting frequency in the type II Δku80 Δhxgprt strain measured at the orotate (OPRT) and the uracil (UPRT) phosphoribosyltransferase loci was highly efficient. To assess the potential of the type II Δku80 Δhxgprt strain to examine gene function affecting cyst biology and latent stages of infection, we targeted the deletion of four parasite antigen genes (GRA4, GRA6, ROP7, and tgd057 …

Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The filamentous fungus, Magnaporthe oryzae, responsible for blast rice disease, destroys around 10-30% of the rice crop annually. Infection begins when the specialized infection structure, the appressorium, generates enormous internal turgor pressure through the accumulation of glycerol. This turgor acts on a penetration peg emerging at the base of the cell, causing it to breach the leaf surface allowing its infection.

The enzyme trehalose-6- phosphate synthase (Tps1) is a central regulator of the transition from appressorium development to infectious hyphal growth. In the first chapter we show that initiation of rice blast disease requires a regulatory mechanism involving an …