Pathogenic Microbiology Commons^™

Serologic Assessment Of Antigenic Type-V And Other Outer Membrane Proteins From Brucella Species As Differential Diagnostic Targets For Brucellosis, Samantha D. Lambert`

Honors Theses AY 16/17

The Type V auto-secreting proteins of Gram-negative bacterial pathogens have been shown to be important surface-expressed molecules that facilitate colonization and in vivo survival. In particular, Brucella species have been shown to carry genes with the potential to express several Type V and Type V-like secreted proteins that are antigenic, possess putative virulence function, and may very well contribute to persistence of the microorganism in susceptible hosts (cattle, pigs, bison, sheep, and cervids [elk and deer]). Additionally, some of these proteins may be differentially surface-expressed and thus potentially represent species-specific markers. Experiments were therefore conducted to assess the feasibility of ...

Burkholderia Cenocepacia J2315-Mediated Destruction Of Staphylococcus Aureus Nrs77 Biofilms., Rachel Thompson

College of Arts & Sciences Senior Honors Theses

Cystic fibrosis (CF) is an inherited disorder that affects over 30,000 people in the US and more than 70,000 people worldwide. Recurring bacterial infections in CF patients result in tissue damage that dramatically lowers respiratory function and are ultimately fatal. The formation of bacterial biofilms in the mucus and on lung epithelial tissue allows pathogens to be protected from antibiotics and the host immune system, making treatment of infection difficult. The interactions between CF pathogens in co-culture biofilms are not well understood and were examined in this study. Staphylococcus aureus and Burkholderia cenocepacia, two common CF pathogens, were ...

Molecular Subtyping Of Staphylococcus Aureus Isolates From The U.P. Community For The Presence Of Toxin-Encoding Genes, Carol I. Kessel

All NMU Master's Theses

Staphylococcus aureus is the most common cause of human bacterial infections; however, humans can also be asymptomatically colonized with S. aureus. Asymptomatic carriers can potentially spread S. aureus infection to others. These infections can range from mild to severe. The pathology of a S. aureus infection is often dependent on which toxins are expressed and the virulence factors with which they are associated. One goal of this study was to isolate S. aureus from healthy, consenting adult volunteers who submitted nasal swabs for culture and qRT-PCR analysis to determine which strains are present in the community. This knowledge could potentially ...

Non-Capsular Virulence Factors Of Cryptococcus Neoformans, Kirk Nickish

Senior Honors Theses

Cryptococcus neoformans is an emerging pathogen that kills hundreds of thousands every year, especially in underdeveloped areas with little access to modern medical care. New treatments for the disease are needed to shorten treatment and decrease the side effects and costs associated with the drugs currently in use. Many C. neoformans genes have been identified that are necessary for full virulence in the host. Cir1, a regulatory protein associated with iron regulation, and Zip1, a surface zinc transporter, are both necessary for full virulence in the host. Anti-fungals targeted at these proteins or the proteins produced by other genes discussed ...

The Effect Of Photoactivated Tmp On Burkholderia Cepacia Biofilms, Reyna G. Osorio, Chandra N. Swiech, Tracy L. Collins

The Research and Scholarship Symposium

Burkholderia cepacia is an opportunistic pathogen that causes infections in immunocompromised individuals such as cystic fibrosis patients. B. cepacia infections are typically characterized by the formation of complex communities of cells known as biofilms. Because B. cepacia biofilms are difficult to eradicate using antibiotics, it is important to pursue alternative treatment methods. Photodynamic therapy (PDT) is a type of therapy that uses light, a photosensitizer, and oxygen to elicit cell death through the production of reactive oxygen species. PDT has been shown in previous studies to be successful in killing both Pseudomonas aeruginosa and Staphylococcus aureus. In this study, we ...

E,E-Farnesol Inhibits Swarming Motility In Burkholderia Cepacia Through Rhamnolipid Production, Stephanie E. Nicholls, Alayna N. Sanderson, Andrea P. Schwartz, Lauren E. Ward, Jessica N. Weisensee, Molly Yandrofski, Tracy L. Collins

The Research and Scholarship Symposium

Burkholderia cepacia and Candida albicans both exhibit cell-to-cell communication through the use of quorum-sensing molecules (QSM) known as autoinducers. E,E-farnesol is a QSM produced by C. albicans which regulates its conversion from yeast to mycelium. Because there is a positive correlation between the presence of B. cepacia and C. albicans in the lungs of individuals with cystic fibrosis (CF), we examined whether E,E-farnesol had an effect on swarming motility in B. cepacia. Swarming motility was inhibited when B. cepacia was exposed to 250 µM of E,E-farnesol. In addition, there was a 26.8% decrease in rhamnolipid production ...

Minimum Inhibitory Concentration Of Essential Oils On Candida Fungus, Geoffrey Elliot Lester

Georgia State Undergraduate Research Conference

No abstract provided.

Genomic Analysis Of Factors Associated With Low Prevalence Of Antibiotic Resistance In Extraintestinal Pathogenic Escherichia Coli Sequence Type 95 Strains, Craig M. Stephens, Sheila Adams-Sapper, Manraj Sekhon, James R. Johnson, Lee W. Riley

Biology

Extraintestinal pathogenic Escherichia coli (ExPEC) strains belonging to multilocus sequence type 95 (ST95) are globally distributed and a common cause of infections in humans and domestic fowl. ST95 isolates generally show a lower prevalence of acquired antimicrobial resistance than other pandemic ExPEC lineages. We took a genomic approach to identify factors that may underlie reduced resistance. We fully assembled genomes for four ST95 isolates representing the four major fimH-based lineages within ST95 and also analyzed draft-level genomes from another 82 ST95 isolates, largely from the western United States. The fully assembled genomes of antibiotic-resistant isolates carried resistance genes exclusively on ...

Neurotrophic Factors Ngf, Gdnf And Ntn Selectively Modulate Hsv1 And Hsv2 Lytic Infection And Reactivation In Primary Adult Sensory And Autonomic Neurons, Andy Y. Yanez, Telvin Harrell, Heather J. Sriranganathan, Angela M. Ives, Andrea S. Bertke

Medical Diagnostics & Translational Sciences Faculty Publications

Herpes simplex viruses (HSV1 and HSV2) establish latency in peripheral ganglia after ocular or genital infection, and can reactivate to produce different patterns and frequencies of recurrent disease. Previous studies showed that nerve growth factor (NGF) maintains HSV1 latency in embryonic sympathetic and sensory neurons. However, adult sensory neurons are no longer dependent on NGF for survival, some populations cease expression of NGF receptors postnatally, and the viruses preferentially establish latency in different populations of sensory neurons responsive to other neurotrophic factors (NTFs). Thus, NGF may not maintain latency in adult sensory neurons. To identify NTFs important for maintaining HSV1 ...

Ticks Elicit Variable Fibrinogenolytic Activities Upon Feeding On Hosts With Different Immune Backgrounds, Ashish Vora, Vikas Taank, John F. Anderson, Durland Fish, Daniel E. Sonenshine, John D. Catravas, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ticks secrete several anti-hemostatic factors in their saliva to suppress the host innate and acquired immune defenses against infestations. Using Ixodes scapularis ticks and age-matched mice purchased from two independent commercial vendors with two different immune backgrounds as a model, we show that ticks fed on immunodeficient animals demonstrate decreased fibrinogenolytic activity in comparison to ticks fed on immunocompetent animals. Reduced levels of D-dimer (fibrin degradation product) were evident in ticks fed on immunodeficient animals in comparison to ticks fed on immunocompetent animals. Increased engorgement weights were noted for ticks fed on immunodeficient animals in comparison to ticks fed on ...

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 ...

Bathing In Bacteria: Mycobacteria Relative Abundance On Showerhead Biofilms, Robin G. Hacker-Cary

Undergraduate Honors Theses

Mycobacterium is a genus of Actinobacteria that contains many human pathogens, causing diseases such as tuberculosis, leprosy, and nontuberculous mycobacteria (NTM) lung disease. Diagnosed cases of NTM lung disease, are increasing rapidly across the United States. Recent studies have indicated that this respiratory infection is acquired through the inhalation of aerosolized mycobacteria derived from the biofilms found on the inside of household showerheads.

To asses the factors that influence mycobacteria abundance on the interior biofilms of showerheads we analyzed bacterial and protistan communities from showerhead samples gathered across the United States. Further, we investigated water chemistry, specifically total chorine concentration ...

Loss Of Outer Membrane Porins In Clonally Related Clinical Isolates Of Klebsiella Pneumoniae Modifies The Bacteria; Resulting In Altered Resistance To Phagocytosis By Macrophages, Debra Nickole Brunson

UNF Theses and Dissertations

Klebsiella pneumoniae is an opportunistic pathogen responsible for lobar pneumoniae, liver abscess, and septicemia. Clinical isolates are found to be extended spectrum beta lactamase positive with differential expression of the two classical porins, OmpK35 and OmpK36. Porin loss is associated with increased minimum inhibitory concentrations of beta lactam, cephalosporin, and carbapenem antibiotics that target the peptidoglycan. However, little is known about how porin loss affects other aspects of the cell envelope. The focus of this study was to characterize clinical isolates exhibiting differential porin expression and determine if the cumulative changes altered the resistance to phagocytosis by macrophages. The results ...

Molecular Biology Of A Surface-Exposed Protein Family Of Bartonella Bacilliformis, Hannah Fay

Undergraduate Theses and Professional Papers

Bartonella bacilliformis is a gram negative alpha-proteobacterium native to the Andes of South America. Bartonella causes Carrion’s disease, a potentially life threatening disease transmitted by the sand fly. It has a mortality rate of 88% when untreated and 10% when treated. Diagnostics and control measures for the disease are underdeveloped and no vaccine is available. Recent outbreaks indicate that the range of the pathogen is increasing with nearly 1.7 million people in western South America at risk. Little is known about the epidemiology and pathogenesis of B. bacilliformis. Recent research done by UC San Diego found a paralogous ...

Molecular Diversity Of Foliar Fungal Endophytes In Relation To Defense Strategies And Disease In Whitebark Pine, Lorinda Bullington 5474413

Graduate Student Theses, Dissertations, & Professional Papers

An invasive fungal pathogen, Cronartium ribicola (the causative agent of white pine blister rust) infects and kills whitebark pine (Pinus albicaulis) throughout the western US. Blister rust has decreased whitebark pine populations by over 90% in some areas. Whitebark pine, a keystone species, has been proposed for listing under the Endangered Species Act in the U.S., and the loss of this conifer is predicted to have severe impacts on forest composition and function in high elevations. Hundreds of asymptomatic fungal species live inside whitebark pine tissue, and recent studies suggest that these fungi can influence the frequency and severity ...

Jmh Dissertation 2016.Pdf, Jennifer Hayashi

Jennifer Hayashi

A Portable And Automatic Biosensing Instrument For Detection Of Foodborne Pathogenic Bacteria In Food Samples, Zhuo Zhao

Theses and Dissertations

Foodborne diseases are a growing public health problem. In recent years, many rapid detection methods have been reported, but most of them are still in lab research and not practical for use in the field. In this study, a portable and automatic biosensing instrument was designed and constructed for separation and detection of target pathogens in food samples using nanobead-based magnetic separation and quantum dots (QDs)-labeled fluorescence measurement. The instrument consisted of a laptop with LabVIEW software, a data acquisition card (DAQ), a fluorescent detector, micro-pumps, stepper motors, and 3D printed tube holders. First, a sample in a syringe ...

Il-21 Signaling Is Essential For Optimal Host Resistance Against Mycobacterium Tuberculosis Infection, Matthew G. Booty, Palmira Barreira-Silva, Stephen Carpenter, Claudio Nunes-Alves, Miye K. Jacques, Britni L. Stowell, Pushpalatha Jayaraman, Gillian Beamer, Samuel M. Behar

Open Access Articles

IL-21 is produced predominantly by activated CD4+ T cells and has pleiotropic effects on immunity via the IL-21 receptor (IL-21R), a member of the common gamma chain (gammac) cytokine receptor family. We show that IL-21 signaling plays a crucial role in T cell responses during Mycobacterium tuberculosis infection by augmenting CD8+ T cell priming, promoting T cell accumulation in the lungs, and enhancing T cell cytokine production. In the absence of IL-21 signaling, more CD4+ and CD8+ T cells in chronically infected mice express the T cell inhibitory molecules PD-1 and TIM-3. We correlate these immune alterations with increased susceptibility ...

The Roles Of Biotin In Candida Albicans Physiology, Nur Ras Aini Ahmad Hussin

Dissertations and Theses in Biological Sciences

Due to the increased number of immunocompromised patients, infections by Candida albicans have significantly increased in recent years. C. albicans transition from yeast to germ tubes is an essential factor for virulence. In this study we noted that Lee's medium, commonly used to induce filamentation, contained 500-fold more biotin than needed for growth. Thus, we investigated the effects of excess biotin on growth rate and filamentation by C. albicans in different media. At 37 °C, excess biotin (4 µM) enhanced germ tube formation (GTF) ca. 10-fold in both Lee's medium and a defined glucose proline medium, and ca ...

Improving Food Safety In Meat And Poultry: Will New Regulations Benefit Consumers?, Laurian J. Unnevehr, Tanya Roberts, Helen H. Jensen

Helen Jensen

The Centers for Disease Control and Prevention (CDC) state that "food­ borne disease remams one of the most common and important cases of illness and deaths" (Harman, et al., 1991). According to researchers at CDC and the U.S. Food and Drug Administration (FDA), 6.5 million to 33 million illnesses and up to 9,000 deaths may occur each year from foodborne pathogens (namely, bactena, parasites, virus­ es, and fungi). For just the few foodborne bacterial and parasitic diseases for which there are cost estimates, medical costs, and lost productivity cost society $6.5 to $35 bil­ lion annually ...