Pathogenic Microbiology Commons^™

Simulating Antibiotic Resistance In The Computer Lab And Biology Lab: Ideas For Undergraduate Projects, Anne E. Yust

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.

Lack Of Evidence For Erm(B) Infiltration Into Erythromycin-Resistant Campylobacter Coli And Campylobacter Jejuni From Commercial Turkey Production In Eastern North Carolina: A Major Turkey-Growing Region In The United States, Hannah K. Bolinger, Qijing Zhang, William G. Miller, Sophia Kathariou

Veterinary Microbiology and Preventive Medicine Publications

In Campylobacter spp., resistance to erythromycin and other macrolides has typically implicated ribosomal mutations, especially substitutions in the 23S rRNA genes. However, in 2014, the macrolide resistance gene erm(B) was reported for the first time in Campylobacter and shown to be harbored by a multidrug resistance island in the chromosome of the swine-derived strain Campylobacter coli ZC113. erm(B)-positive C. coli and Campylobacter jejuni strains from the food supply have been mostly reported from China. However, erm(B)-positive C. coli isolates were also detected recently in fecal samples from turkeys in Spain. To determine whether erm(B ...

High-Throughput Nanoliter Dispensing Device For Biological Applications, Cole Reynolds, Euiwon Bae Dr., J Paul Robinson Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Pathogen identification is a field that can contribute largely to the prevention of the spreading of illness and disease. In the past, pathogen identification has been a long and arduous process due to the time-consuming processes and steps that requires technician’s time and effort. With new technologies emerging however, screening of bacteria colonies can be done in a quick and high-throughput way. The problem is that using the current methods, bacteria cannot be transferred to petri dishes fast enough to keep up with the new screening methods. The current study focuses on exploring different methods to create an ergonomic ...

The Role Of Eukaryotic Abc-Transporters In Eliciting Neutrophil Infiltration During Streptococcus Pneumoniae Infection, Andrew Zukauskas

GSBS Dissertations and Theses

Streptococcus pneumoniae (S. pneumoniae) is a Gram-positive, encapsulated bacterium capable of causing significant morbidity and mortality throughout the world. A hallmark of S. pneumoniae infection is infiltration of neutrophils (PMNs) that assist in controlling the spread infection but may also contribute to pathology. Paradoxically, studies have shown that limiting PMN infiltration into the lumen of the lung during infection actually betters clinical outcome in experimental S. pneumoniae infection. The final step in PMN luminal trafficking is a Hepoxilin A3 (HXA₃)-dependent migration across the pulmonary epithelium. HXA₃ is a PMN chemoattractant that forms gradients along the polarized epithelial ...

The Unusual Paradigm Of The Acid Response Two Component System Of Helicobacter Pylori, Anna Kenan

Undergraduate Honors Theses

Two component signal transduction systems in bacteria are key for environmental adaptation. Signaling via these systems is traditionally considered to be relatively simple, only involving interactions between the sensory protein and its cognate response regulator. The ArsRS two component system is vital for the acid response in Helicobacter pylori. This study investigates the mechanism by which ArsRS responds to acid in H pylori. Recent studies in our lab have challenged the the classic model in which the response regulator ArsR is activated by the phosphorylation of a conserved aspartic acid by the transfer of a phosphoryl group from a histidine ...

Characterizing The Virulence Factor Yape In Yersinia Pestis., Tiva Templeton Vancleave

Electronic Theses and Dissertations

Yersinia pestis is the causative agent of bubonic plague and is primarily transmitted by fleas. Upon infection, the bacteria rapidly travel to the regional lymph nodes causing inflammation and cellulitis in these tissues (referred to as buboes). Two outer membrane proteins, YapE and Pla, have been implicated to have roles in dissemination to the lymph nodes. Their adhesive properties have shown that they are able to interact with host macrophages thereby increasing their ability to disseminate to regional lymph nodes. More recently, we have shown that YapE is cleaved by another virulence factor important for lymph node colonization, Pla, to ...

Characterization Of Type Ii Toxin Anti-Toxin Systems In Aggregatibacter Actinomycetemcomitans., Blair W. Schneider

Electronic Theses and Dissertations

Microbes express many protective mechanisms in response to environmental stress. Toxin/anti-toxin systems encode a biologically active toxin and a labile anti-toxin that inhibits the toxin’s activity. These systems are known to contribute to persister cell and biofilm formation. A. actinomycetemcomitans thrives in the complex oral microbial community and is subjected to continual environmental flux. Little is known regarding the presence and function of TA systems in this organism or their contribution survival in the oral environment. Using BLAST searches and other informatics tools, we identified 11 intact TA systems that are conserved across all seven serotypes of A ...

Nutritional Virulence Of Legionella Pneumophila., Ashley M. Best

Electronic Theses and Dissertations

Legionella pneumophila is an environment organism that parasitizes a wide range of protozoa. Growth within the environmental host primes L. pneumophila for infection of human alveolar macrophages when contaminated aerosols are inhaled. Intracellular replication within either host requires the establishment a replicative niche, known as the Legionella-containing vacuole (LCV). Biogenesis of the LCV depends on the type IVb translocation system, the Dot/Icm, to translocation >320 effectors into the host cytosol. Effectors are responsible for preventing lysosome fusion to the LCV, recruitment of ER-derived vesicles to the LCV, and modulation of a plethora of host processes to promote the ...

Changes In The Prevalence Of Salmonella Serovars Associated Swine Production And Correlations Of Avian, Bovine And Swine‐Associated Serovars With Human‐Associated Serovars In The United States (1997–2015), Chaohui Yuan, Adam C. Krull, Chong Wang, M. Erdman, P. J. Fedorka-Cray, C. M. Logue, Annette M. O'Connor

Veterinary Diagnostic and Production Animal Medicine Publications

As Salmonella enterica is an important pathogen of food animals, surveillance programmes for S. enterica serovars have existed for many years in the United States. Surveillance programmes serve many purposes, one of which is to evaluate alterations in the prevalence of serovars that may signal changes in the ecology of the target organism. The primary aim of this study was to evaluate changes in the proportion of S. enterica serovars isolated from swine over a near 20‐year observation period (1997–2015) using four longitudinal data sets from different food animal species. The secondary aim was to evaluate correlations between ...

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 ...

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

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 ...

On The Demographic And Selective Forces Shaping Patterns Of Human Cytomegalovirus Variation Within Hosts, Andrew M. Sackman, Susanne P. Pfeifer, Timothy F. Kowalik, Jeffrey D. Jensen

Open Access Articles

Human cytomegalovirus (HCMV) is a member of the beta -herpesvirus subfamily within Herpesviridae that is nearly ubiquitous in human populations, and infection generally results only in mild symptoms. However, symptoms can be severe in immunonaive individuals, and transplacental congenital infection of HCMV can result in serious neurological sequelae. Recent work has revealed much about the demographic and selective forces shaping the evolution of congenitally transmitted HCMV both on the level of hosts and within host compartments, providing insight into the dynamics of congenital infection, reinfection, and evolution of HCMV with important implications for the development of effective treatments and vaccines.

Size-Dependent Inhibitory Effects Of Antibiotic Drug Nanocarriers Against Pseudomonas Aeruginosa, Feng Ding, Preeyaporn Songkiatisak, Pavan Kumar Cherukuri, Tao Huang, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Multidrug membrane transporters (efflux pumps) are responsible for multidrug resistance (MDR) and the low efficacy of therapeutic drugs. Noble metal nanoparticles (NPs) possess a high surface-area-to-volume ratio and size-dependent plasmonic optical properties, enabling them to serve both as imaging probes to study sized-dependent MDR and as potential drug carriers to circumvent MDR and enhance therapeutic efficacy. To this end, in this study, we synthesized three different sizes of silver nanoparticles (Ag NPs), 2.4 ± 0.7, 13.0 ± 3.1, and 92.6 ± 4.4 nm, functionalized their surface with a monolayer of 11-amino-1-undecanethiol (AUT), and covalently conjugated them with ...

The Role Of The Metallochaperone Hypa In The Acid Survival And Activities Of Nickel Enzymes In Helicobacter Pylori, Heidi Hu

Doctoral Dissertations

Helicobacter pylori is a bacterium that has colonized the human gastric mucosa of over 50% of the world population. Persistent infection can cause gastritis, peptic ulcers, and cancers. The ability of H. pylori to colonize the acidic environment of the human stomach is dependent on the activity of the nickel containing enzymes, urease and NiFe-hydrogenase. The nickel metallochaperone, HypA, was previously shown to be required for the full activity of both enzymes. In addition to a Ni-binding site, HypA also contains a structural Zn site, which has been characterized to alter its averaged structure depending on pH and the presence ...

Evolution Of Bordetella Pertussis Genome May Play A Role In The Increased Rate Of Whooping Cough Cases In The United States, Kevin Loftus

Senior Honors Projects, 2010-current

Bordetella pertussis is the bacterium responsible for pertussis, a disease commonly referred to as whooping cough. Recently, pertussis has made a resurgence in the U.S. despite high-vaccination coverage. Possible causes of the increased number of pertussis cases include genetic evolution of B. pertussis, increased awareness of the disease, better laboratory diagnostics, and the switch from a whole-cellular (wP) vaccine to an acellular vaccine (aP) in the 1990s. Fortunately, just as B. pertussis is evolving, so is the arsenal of technologies used to understand and combat this pathogenic bacterium. Whole genome sequencing is one technology that helps researchers better understand ...

Antibacterial Properties Of Novel Amphiphiles: Exploring Structure-Activity Relationships, Reafa Hossain

Senior Honors Projects, 2010-current

The increased cases of antibiotic resistance have large implication in hospital settings where infections by antibiotic resistant bacteria are harder to treat resulting in longer stays at the hospital, which drastically increases the costs to patients and hospitals. To address this matter, many research groups are searching for an alternative to antibiotics. One option is the development of amphiphiles, some of which have antibacterial properties. Amphiphiles contain a hydrophilic, polar head group, and a hydrophobic, nonpolar tail, which may intercalate into the cell membrane, resulting in cell lysis. Understanding the impact of amphiphile geometry on antibacterial activity allows for the ...

Comparison Between Listeria Sensu Stricto And Listeria Sensu Lato Strains Identifies Novel Determinants Involved In Infection, Jakob Schardt, Grant Jones, Stefanie Müller-Herbst, Kristina Schauer, Sarah E. F. D'Orazio, Thilo M. Fuchs

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The human pathogen L. monocytogenes and the animal pathogen L. ivanovii, together with four other species isolated from symptom-free animals, form the "Listeria sensu stricto" clade. The members of the second clade, "Listeria sensu lato", are believed to be solely environmental bacteria without the ability to colonize mammalian hosts. To identify novel determinants that contribute to infection by L. monocytogenes, the causative agent of the foodborne disease listeriosis, we performed a genome comparison of the two clades and found 151 candidate genes that are conserved in the Listeria sensu stricto species. Two factors were investigated further in vitro and in ...

Fluorescence-Reported Allelic Exchange Mutagenesis Reveals A Role For Chlamydia Trachomatis Tmea In Invasion That Is Independent Of Host Ahnak, M. J. Mckuen, Konrad E. Mueller, Y. S. Bae, Kenneth A. Fields

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Development of approaches to genetically manipulate Chlamydia is fostering important advances in understanding pathogenesis. Fluorescence-reported allelic exchange mutagenesis (FRAEM) now enables the complete deletion of specific genes in C. trachomatis L2. We have leveraged this technology to delete the coding sequences for a known type III effector. The evidence provided here indicates that CT694/CTL0063 is a virulence protein involved in chlamydial invasion. Based on our findings, we designate the gene product corresponding to ct694-ctl0063 translocated membrane-associated effector A (TmeA). Deletion of tmeA did not impact development of intracellular chlamydiae. However, the absence of TmeA manifested as a decrease in ...

Experimental Approaches To Understand And Control Salmonella Infection In Poultry, Yichao Yang

Theses and Dissertations

Salmonella is a major foodborne pathogen around the world and chickens are the major reservoir to transmit Salmonella into the human food chain. For decreasing the infection of Salmonella, we developed six attenuated live vaccines based on Salmonella Enteritidis (SE) and Typhimurium (ST) for testing the cross-serovar and cross-serogroup protection from the challenge of Salmonella Heidelberg and Campylobacter jejuni. One of the constructed vaccine strain showed ability to protect against challenge from Salmonella Heidelberg. Even though some preventive approaches are able to decrease Salmonella colonization in the gastrointestinal tract of chickens or other farm animals, Salmonella transmission mechanisms remain unclear ...

Role Of Incompatibility Group 1 (Inci1) Plasmid-Encoded Factors On Salmonella Enterica Antimicrobial Resistance And Virulence, Pravin Raghunath Kaldhone

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 ...