Organisms Commons^™

Peptidomimetic Small Molecules Disrupt Type Iv Secretion System Activity In Diverse Bacterial Pathogens, Carrie L. Shaffer, James A.D. Good, Santosh Kumar, K. Syam Krishnan, Jennifer A. Gaddy, John T. Loh, Joseph Chappell, Fredrik Almqvist, Timothy L. Cover, Maria Hadjifrangiskou

Pharmaceutical Sciences Faculty Publications

Bacteria utilize complex type IV secretion systems (T4SSs) to translocate diverse effector proteins or DNA into target cells. Despite the importance of T4SSs in bacterial pathogenesis, the mechanism by which these translocation machineries deliver cargo across the bacterial envelope remains poorly understood, and very few studies have investigated the use of synthetic molecules to disrupt T4SS-mediated transport. Here, we describe two synthetic small molecules (C10 and KSK85) that disrupt T4SS-dependent processes in multiple bacterial pathogens. Helicobacter pylori exploits a pilus appendage associated with the cag T4SS to inject an oncogenic effector protein (CagA) and peptidoglycan into gastric epithelial cells. In …

Antibacterial Derivatives Of Marine Algae: An Overview Of Pharmacological Mechanisms And Applications, Emer Shannon, Nissreen Abu-Ghannam

Articles

The marine environment is home to a taxonomically diverse ecosystem. Organisms such as algae, molluscs, sponges, corals, and tunicates have evolved to survive the high concentrations of infectious and surface-fouling bacteria that are indigenous to ocean waters. Both macroalgae (seaweeds) and microalgae (diatoms) contain pharmacologically active compounds such as phlorotannins, fatty acids, polysaccharides, peptides, and terpenes which combat bacterial invasion. The resistance of pathogenic bacteria to existing antibiotics has become a global epidemic. Marine algae derivatives have shown promise as candidates in novel, antibacterial drug discovery. The efficacy of these compounds, their mechanism of action, applications as antibiotics, disinfectants, and …

Epidemiology Crucial To Cracking Elizabethkingia Crisis, Angela Tonozzi

Journal of Patient-Centered Research and Reviews

The author explains the epidemiological methods, tools and personnel required to pinpoint the source of Wisconsin’s 2016 outbreak of Elizabethkingia infections.

Bacteriophages: The Answer To Antibiotic Resistance?, Allie Casto, Adam Hurwitz, Kunny Kou, Gregory Mansour, Allison Mayzel, Rachel Policke, Alexander Schmidt, Rowan Shartel, Olivia Smith, Augustus Snyder, Allison Woolf

James Madison Undergraduate Research Journal (JMURJ)

Bacteriophages, viruses that infect bacteria, have numerous applications in the medical, agricultural, and research fields, especially as an alternative to antibiotics in the age of antibiotic resistance. Phages are able to lyse, or break apart, bacterial cells with fewer side effects, more specificity, and less likelihood of resistance than antibiotics. The acceptance of phages in medicine and agriculture around the world today is not universal, and the United States Food and Drug Administration (FDA) has been slow to recognize phage therapy as a legitimate treatment. However, the successful use of phages in the past, as well as promising trial results …

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 …

An Analysis Of Bacterial Contamination Of Chicken Eggs And Antimicrobial Resistance, Holly Spitzer

All College Thesis Program, 2016-2019

Chicken eggs are a major component of American diets, with an average yearly consumption of approximately 250 eggs per person (American Humane Society). While highly nutritious, eggs are also one of the leading causes of food poisoning and food borne illness in the United States. Eggs may become contaminated by a number of different types of bacteria during production, including Salmonella, a group of bacteria that, according to the CDC, causes more than 1.2 million cases of food borne illness in the United States every year. In an effort to decrease the frequency of bacterial contamination, many food producers …

Graphene Oxide Quantum Dots Covalently Functionalized Pvdf Membrane With Significantly-Enhanced Bactericidal And Antibiofouling Performances, Zhiping Zeng, Dingshan Yu, Ziming He, Jing Liu, Fang-Xing Xiao, Yan Zhang, Rong Wang, Dibakar Bhattacharyya, Timothy Thatt Yang Tan

Chemical and Materials Engineering Faculty Publications

Covalent bonding of graphene oxide quantum dots (GOQDs) onto amino modified polyvinylidene fluoride (PVDF) membrane has generated a new type of nano-carbon functionalized membrane with significantly enhanced antibacterial and antibiofouling properties. A continuous filtration test using E. coli containing feedwater shows that the relative flux drop over GOQDs modified PVDF is 23%, which is significantly lower than those over pristine PVDF (86%) and GO-sheet modified PVDF (62%) after 10 h of filtration. The presence of GOQD coating layer effectively inactivates E. coli and S. aureus cells, and prevents the biofilm formation on the membrane surface, producing excellent antimicrobial activity and …

Expression Levels Of Virulence Genes In Group A Streptococci: A Response To Aerosolized Propylene Glycol, Michael S. Costello

Honors Undergraduate Theses

Electronic cigarette usage is becoming increasingly prevalent among school age children and young adults. A known bactericidal agent, propylene glycol, is often used as a carrier for nicotine, flavoring, and additional constituents of electronic cigarette juice. This study examined the relationship between propylene glycol and virulence gene expression in Streptococcus pyogenes, a respiratory tract pathogen commonly found in school-age individuals. A variety of virulence genes controlled by the three stand alone regulators mga, RofA, and Rgg/RopB were sampled in an effort to understand the pathway by which virulence is affected. The genes chosen encode C5a peptidase, fibronectin binding protein, hyaluronate …

The Effects Of Amixicile, A Pyruvate Ferredoxin Oxidoreductase Inhibitor, On Oral Treponemes, Lucas A. Reed

Theses and Dissertations

Periodontal disease (PD) is a polymicrobial infection characterized by inflammation of the gingiva, alveolar bone resorption, and tooth loss (edentulism). Treponema denticola along with Porphyromonas gingivalis and Tannerella forsythia are among the “Red Complex” and are main etiological agents in PD. Treponemes are a member of the Spirochaeta phylum and are obligate anaerobes, that express pyruvate ferredoxin oxidoreductase (PFOR). The enzyme catalyzes the oxidation of pyruvate to acetyl-CoA and reduced ferredoxin. Amixicile is a novel bacteriostatic derivative of nitazoxanide and an inhibitor of PFOR. In light of the fact that Treponemes express PFOR, this study was conducted to investigate the …

Investigation Of Anaplasma Phagocytophilum And Anaplasma Marginale Adhesin-Host Cell Interactions, Kathryn S. Hebert

Theses and Dissertations

Anaplasma phagocytophilum and A. marginale are the etiologic agents of bovine anaplasmosis and human granulocytic anaplasmosis, respectively. As obligate intracellular pathogens, binding and entry of host cells is a prerequisite for survival. The molecular events associated with these processes are poorly understood. Identifying the adhesins mediating binding, delineating their key functional domains, and determining the molecular determinants to which they bind not only benefits better understanding of Anaplasma spp. pathobiology, but could also benefit the development of novel approaches for protecting against infection. We previously demonstrated that A. phagocytophilum outer membrane protein A (ApOmpA) is critical for bacterial binding and …

In Vitro Activity Of Polymyxin B And Meropenem Alone And In Combination Against Carbapenem-Resistant Enterobacteriaceae, Brandon T. Kulengowski

Theses and Dissertations--Pharmacy

Background: Infections caused by carbapenem-resistant Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae are among the most urgent threats of the infectious disease realm. The incidence of these infections has only been increasing over the years and due to very limited treatment options, mortality is estimated at about 50%.

Methods: To evaluate the in vitro activity of meropenem and polymyxin B against carbapenem-resistant Enterobacteriaceae, antimicrobial susceptibility testing and time-kill studies were performed on K. pneumoniae clinical isolates representing a wide range of meropenem resistance (MICs 4 – 128 mg/L).

Results: Regrowth was observed at clinically relevant concentrations of meropenem alone …

Wake Me When It's Over- Bacterial Toxin-Antitoxin Proteins And Induced Dormancy, Nathan P. Coussens, Dayle A. Daines

Biological Sciences Faculty Publications

Toxin-antitoxin systems are encoded by bacteria and archaea to enable an immediate response to environmental stresses, including antibiotics and the host immune response. During normal conditions, the antitoxin components prevent toxins from interfering with metabolism and arresting growth; however, toxin activation enables microbes to remain dormant through unfavorable conditions that might continue over millions of years. Intense investigations have revealed a multitude of mechanisms for both regulation and activation of toxin-antitoxin systems, which are abundant in pathogenic microorganisms. This minireview provides an overview of the current knowledge regarding type II toxin-antitoxin systems along with their clinical and environmental implications.

Frequency And Etiology Of Community-Acquired Bloodstream Infection In Hospitalized Febrile Children, Tufail Soomro, Shiyam Sunder Tikmani, Sumera Aziz Ali

Community Health Sciences

Background: Blood stream infection is a serious problem that needs immediate attention and treatment. We aim to identify the frequency of common organisms in blood culture of febrile pediatric patients so that empirical antibiotic therapy can be started timely.
Methods: This cross-sectional study was conducted in pediatric ward Civil Hospital Sukkur from 1st May 2013 to 31st October 2014. Children of both genders who are between the age of one month to 15 years admitted to the pediatric ward with a fever of > 38.0 c and with a history of fever ˃ two days and whose blood culture has been …

Inhibition Of Bacterial Growth And Prevention Of Bacterial Adhesion With Localized Nitric Oxide Delivery, Julia Osborne

Dissertations, Master's Theses and Master's Reports

Bacterial infections continue to be a problem at the site of an indwelling medical device, and over the years, various bacterial strains have become more resistant to current antibiotic treatments. Bacterial infection at an indwelling medical device can be dangerous and affect the performance of the medical device which can ultimately lead to the failure of the device due to bacterial resistance to treatment.

Nitric Oxide (NO) has been shown to possess antibacterial properties to prevent and inhibit bacterial growth. NO releasing coatings on indwelling medical devices could provide a reduction in bacterial infections that occur at the device site …

Preventing 30-Day Readmissions Of Clostridium Difficile Patients Utilizing Targeted Discharge Instructions, Keith A. Howard

Doctor of Nursing Practice (DNP) Projects

The Patient Protection and Affordable Care Act of 2010 ushered in a new era of fiscal accountability for healthcare organizations. Healthcare organizations and providers are now jointly held responsible for the improved quality of patient care and sustained reductions in patient care events termed healthcare-acquired conditions. To ensure compliance with this newly enacted legislation, the Centers for Medicare and Medicaid Services (CMS) began penalizing hospitals for targeted conditions leading to 30-day readmissions beginning in October 2012. Annually, CMS has focused attention on conditions that endanger patient health and welfare while secondarily attempting to reduce the excessive financial expenditures in …

Genetic Control Of Survival And Weight Loss During Pneumonic Burkholderia Pseudomallei (Bp) Infection, Felicia D. Emery

Theses and Dissertations (ETD)

Burkholderia pseudomallei (Bp) is a saprophytic, gram-negative aerobe and the causative agent of the disease melioidosis. Melioidosis is an infectious disease that occurs in humans and animals and is prevalent in Southeast Asia, northern Australia and other tropical areas. Transmission occurs through direct contact with the organism via ingestion, inhalation, or through open wounds and skin abrasions. Clinical presentation is extremely variable and can range from acute septicemia with bacterial dissemination to distant sites, to an isolated pulmonary infection. Treatment of melioidosis can be problematic because it is often difficult to diagnose and Bp is resistant to a diverse group …

Development Of Oral Vaccines Against Lyme Disease, Rita Raquel Dos Anjos De Carvalho E Melo

Theses and Dissertations (ETD)

Lyme Disease, caused by the spirochete Borrelia burgdorferi, is the most common vector-borne disease in the United States and Europe. If left untreated, it can lead to permanent damage to the nervous and musculoskeletal systems. In some cases, patients that receive the recommended antibiotic therapy develop a debilitating health condition associated with substantial health care costs. Despite current preventive measures, the incidence and the geographic distribution of Lyme Disease continues to increase. Recent estimates from CDC suggest that the true number of cases of Lyme Disease in the US is approximately 300,000 per year. Yet, there is currently no vaccine …

Geographic Distribution Of Infant Death During Birth Hospitalization And Maternal Group B Streptococcus Colonization: Eastern Wisconsin, Jessica J.F. Kram, Dennis J. Baumgardner, Kiley A. Bernhard, Melissa A. Lemke

Journal of Patient-Centered Research and Reviews

Background: Neonatal death rate in the United States is 4/1,000 live births; infant death rate is 6/1,000. Group B Streptococcus (GBS) may be transmitted from a colonized mother (rates vary from 15% to 35%) to the newborn during a vaginal delivery, and may contribute to neonatal death.

Purpose: To explore the geographic distribution and associated risk factors for maternal GBS colonization and infant death prior to discharge in eastern Wisconsin births.

Methods: Retrospective study of institutional data from PeriData.net, a comprehensive birth registry, utilizing data from 2007 through 2013 at all Aurora medical centers. Categorical variables were analyzed with chi-square …

Detection Methods And Intestinal Adherence Of Non-O157 Shiga Toxin-Producing Escherichia Coli, Zachary R. Stromberg

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Shiga toxin-producing Escherichia coli (STEC) are enteric pathogens of humans. Cattle serve as a reservoir and harbor STEC in their intestines. Intimin-positive STEC are referred to as enterohemorrhagic E.coli (EHEC). Seven serogroups (O26, O45, O103, O111, O121, O145, and O157) account for the majority of illness due to STEC and are hereafter referred to as STEC/EHEC-7. To improve detection, enrichment broths were compared for supporting growth of STEC-7 and STEC O104:H4 (STEC-8). In pure culture, STEC enriched in trypticase soy broth (TSB) had significantly greater growth compared to TSB containing antimicrobials. In fecal samples, E. coli broth enrichment yielded …

Rapid Label-Free Detection Of E. Coli Using Antimicrobial Peptide Assisted Impedance Spectroscopy, Keren Jieng, Hashem Etayash, Sarfuddin Azmi, Selvaraj Naicker, Mahtab Hassanpourfard, Parmiss Mojir Shaibani, Garima Thakur, Kamaljit Kaur, Thomas Thundat

Pharmacy Faculty Articles and Research

There is an increasing demand for rapid detection of waterborne pathogens to monitor drinking water safety. We demonstrate a compact, label-free sensor array for rapid detection of Escherichia coli (E. coli) in contaminated water samples using antimicrobial peptide assisted impedimetric sensor platform. Interdigitated electrode arrays immobilized with the antimicrobial peptide Colicin V (ColV) were used to screen the affinity towards different bacterial strains by monitoring impedance variations in real-time. This ColV assisted impedance biosensor exhibited high selectivity towards Gram-negative strains particularly towards E. coli strains. This selective detection of E. coli from other strains was observed at 10 …

Application Of Ichip To Grow “Uncultivable” Microorganisms And Its Impact On Antibiotic Discovery, Rinzhin T. Sherpa, Caretta J. Reese, Hamidreza Montazeri Aliabadi

Pharmacy Faculty Articles and Research

Purpose. Antibiotics have revolutionized modern medicine, allowing significant progress in healthcare and improvement in life expectancy. Development of antibiotic resistance by pathogenic bacteria is a natural phenomenon; however, the rate of antibiotic resistance emergence is increasing at an alarming rate, due to indiscriminate use of antibiotics in healthcare, agriculture and even everyday products. Traditionally, antibiotic discovery has been conducted by screening extracts of microorganisms for antimicrobial activity. However, this conventional source has been over-used to such an extent that it poses the risk of “running out” of new antibiotics. Aiming to increase access to a greater diversity of microorganisms, …

Secretion Of Heat-Labile Enterotoxin By Porcine-Origin Enterotoxigenic Escherichia Coli And Relation To Virulence, Prageeth Rukshan Wijemanne

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Heat-labile enterotoxin (LT) is an important virulence factor secreted by some strains of porcine-origin enterotoxigenic Escherichia coli (pETEC). The prototypic human-origin strain H10407 secretes LT via a type II secretion system (T2SS), but its presence or importance in pETEC has not been established. Exposure of pETEC to glucose has been shown to result in different secretion levels of LT. Furthermore, the relationship between the level of LT secreted and the virulence potential of the respective pETEC strain has not been established. To determine the relationship between the capacity to secrete LT and virulence in wild-type (WT) pETEC, 16 strains isolated …

Draft Genome Sequences Of Six Different Staphylococcus Epidermidis Clones, Isolated Individually From Preterm Neonates Presenting With Sepsis At Edinburgh's Royal Infirmary, Paul Walsh, M. Bekaert, J. Carroll, T. Manning, B. Kelly, A. O'Driscoll, X. Lu, C. Smith, P. Dickinson, K. Templeton, P. Ghazal, Roy D. Sleator

Department of Biological Sciences Publications

Herein, we report the draft genome sequences of six individual Staphylococcus epidermidis clones, cultivated from blood taken from different preterm neonatal sepsis patients at the Royal Infirmary, Edinburgh, Scotland, United Kingdom.

Puffs And Tufts: A Comparison Of Trichodesmium Colony Formations And Nutrient Availability Across The North Atlantic Ocean Using Remote Sensing Methods, Marc Rosenfield

Student Scholar Symposium Abstracts and Posters

Trichodesmium, a genus of diazotrophic bacteria, has the capability and the population to produce a large percentage of the total oceanic N2-fixation. Though their population is known to be heavily dependent on two of the ocean’s largest limiting factors, phosphorus and iron concentrations, it is unknown what affect these factors have on the population. In this study two of the largest colony formations of Trichodesmium in the North Atlantic, tufts and puffs, are compared nutrient quality with respect to time and geographical location. Though very little nutrient in situ data was collected from the cruise, remote sensing data collected from …

Identification Of The Staphylococcal Cassette Chromosome Mec (Sccmec) Element In Viral Fractions From Environmental Samples, Emily M. Pelto

Senior Honors Projects, 2010-2019

Antibiotic resistance attributed to methicillin-resistant Staphylococcus aureus (MRSA) has become a growing concern over the last decade in both the healthcare and agricultural environment. This resistance is encoded by the gene mecA that is located on a mosaic, mobile genetic element called the Staphylococcal Cassette Chromosome mec (SCCmec) element. It is proposed that the transfer of the SCCmec element and resulting spread of resistance occur by transduction, the transfer of genetic material from bacterium to bacterium by a bacteriophage. Specifically, it is hypothesized that the transduction of this resistance is occurring in the agricultural setting. To test …

Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage

Senior Honors Projects, 2010-2019

As Malagasy amphibians are facing an impending extinction crisis from the lethal skin fungus Batrachochytrium dendrobatidis (Bd), it has become imperative to proactively mitigate the threat. Bd sporangia develop in the skin of infected amphibians and cause the skin to thicken, leading to ionic imbalance and eventual heart failure. It has been shown that certain bacterial species are able to inhibit Bd growth on amphibians by producing antifungal metabolites. Community-based probiotics are one approach used to combat chytridomycosis by inoculating an environment with Bd-inhibitory bacteria so that many amphibian species are treated at once. With this method, it is important …

Persister Cell Control Mechanisms In Uropathogenic Escherichia Coli, William H. Law Iii

Senior Honors Projects

Persister cells are a subpopulation of bacteria that demonstrate high tolerance to antibiotics, but revert to sensitivity after antibiotics are removed. The mechanism for induction of the persister cell state and antibiotic tolerance is not completely understood but likely occurs through the establishment of dormancy. Some of the suggested mechanisms for persister cell formation in Escherichia coli include: toxin­-antitoxin systems, starvation, gene regulation by (p)ppGpp, and stochastic formation. In our study we examine the mechanisms behind persistence in the E. coli strain CFT073, a uropathogenic isolate, which forms elevated levels of persisters compared to the laboratory strain MG1655. However, CFT073 …

Characterization Of A Novel Protease In Staphylococcus Aureus, Adam L. Johnson

Theses and Dissertations

A newly discovered cysteine protease, Prp, has been shown to perform an essential, site-specific cleavage of ribosomal protein L27 in Staphylococcus aureus. In Firmicutes and related bacteria, ribosomal protein L27 is encoded with a conserved N-terminal extension that must be removed to expose residues critical for ribosome function. Uncleavable and pre-cleaved variants were unable to complement an L27 deletion in S. aureus, indicating that this N-terminal processing event is essential and likely plays an important regulatory role. The gene encoding the responsible protease (prp) has been shown to be essential, and is found in all organisms …

Impact Of Starch Source On Equine Hindgut Microbial Ecology, Brittany Elizabeth Davis Harlow

Theses and Dissertations--Animal and Food Sciences

Grain inclusion in equine diets can allow starch to reach the hindgut where bacteria compete for the substrate. The hypothesis was that starch introduction would cause a source-dependent press disturbance in equine fecal microflora. Fecal cell suspensions were prepared by differential centrifugation and re-suspension in media with ground corn, oats or wheat. At 24 h, corn had more amylolytics and Group D Gram-positive cocci (GPC), and fewer lactate-utilizing (LU) bacteria and lactobacilli than oats, with wheat being intermediate. Predominant amylolytics were identified by their 16S RNA gene sequence as Enterococcus faecalis (corn, wheat) and Streptococcus bovis (oats). In an in …

First Proof Of Concept Of Sustainable Metabolite Production From High Solids Fermentation Of Lignocellulosic Biomass Using A Bacterial Co-Culture And Cycling Flush System, Wanying Yao, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

To improve the lignocellulose conversion for ABE in high solids fermentation, this study explored the feasibility of cycling the process through the cellulolytic or/and solventogenic phases via intermittent flushing of the fermentation media. Five different flushing strategies (varying medium ingredients, inoculum supplement and cycling through phases) were investigated. Flushing regularly throughout the cellulolytic phase is necessary because re-incubation at 65 °C significantly improved glucose availability by at least 6-fold. The solvents accumulation was increased by 4-fold using corn stover (3-fold using miscanthus) over that produced by flushing only through the solventogenic phase. In addition, cycling process was simplified by re-incubating …