Microbiology Commons^™

Population Genomics And Evolution Of Pseudomonas Aeruginosa, Samara T. Choudhury

Electronic Theses & Dissertations (2024 - present)

Pseudomonas aeruginosa is a Gram-negative bacterium ubiquitous in diverse environments and an opportunistic pathogen in humans. It is a leading cause of chronic lung infections in cystic fibrosis patients and of hospital-acquired pneumonia and sepsis. With a large flexible genome and abundant mobile genetic elements, P. aeruginosa exhibits high levels of antimicrobial resistance (AMR), making it a significant public health threat. Evolutionary processes such as homologous recombination, and horizontal gene transfer generate extensive genomic diversity in this species and facilitate the spread of resistance genes. In this dissertation, I investigate the genetic and evolutionary factors shaping P. aeruginosa population structure …

Caveolin-Mediated Endocytosis: Bacterial Pathogen Exploitation And Host-Pathogen Interaction, Dibyasri Barman, Rishi Drolia

Biological Sciences Faculty Publications

Within mammalian cells, diverse endocytic mechanisms, including phagocytosis, pinocytosis, and receptor-mediated endocytosis, serve as gateways exploited by many bacterial pathogens and toxins. Among these, caveolae-mediated endocytosis is characterized by lipid-rich caveolae and dimeric caveolin proteins. Caveolae are specialized microdomains on cell surfaces that impact cell signaling. Caveolin proteins facilitate the creation of caveolae and have three members in vertebrates: caveolin-1, caveolin-2, and caveolin-3. Many bacterial pathogens hijack caveolin machinery to invade host cells. For example, the Gram-positive facultative model intracellular bacterial pathogen Listeria monocytogenes exploits caveolin-mediated endocytosis for efficient cellular entry, translocation across the intestinal barrier, and cell–cell spread. Caveolin …

Engineering Extracellular Vesicles (Evs) To Combat Infection And Inflammation In Cystic Fibrosis, Sharanya Sarkar

Dartmouth College Ph.D Dissertations

Cystic Fibrosis (CF) is a multisystemic genetic disorder caused by mutations in the CFTR gene, resulting in chronic pulmonary infections, hyperinflammation, and progressive lung damage. Among the pathogens that colonize CF lungs, Pseudomonas aeruginosa (P. aeruginosa) is predominant, infecting over 50% of adults with CF and developing antibiotic resistance over time. Current modulator therapies fail to address persistent bacterial infections, chronic inflammation, or irreversible lung damage, underscoring the need for novel therapeutic strategies. In our previous in vitro studies, we demonstrated that extracellular vesicles (EVs) secreted by primary Human Bronchial Epithelial Cells (HBECs) inhibit P. aeruginosa growth by reducing the …

Biochemical And Molecular Analysis Of Anr-Dependent Microoxic Fitness Factors In Pseudomonas Aeruginosa, Stacie E. Balsam

Dartmouth College Ph.D Dissertations

Pseudomonas aeruginosa is a prominent opportunistic pathogen that is often found in microoxic environments like sites of infection and colony biofilms. P. aeruginosa can grow at oxygen (O2) at concentrations as little as 3 μM and also grows anaerobically by generating energy using nitrate as an alternate electron acceptor. An important way P. aeruginosa adapts to low O2 is through Anr, a transcription factor that upregulates many genes important for microoxic and anoxic fitness.

Specifically, Anr regulates mhr which encodes a hemerythrin protein (Mhr) that binds O2 with affinities relevant to microoxia and is also necessary for full fitness of …

Characterization And Evaluation Of Bacteriophages Φpa-C And Φpa-Tc Infecting Pseudomonas Aeruginosa, Joanne Harrison

Master's Theses

Pseudomonas aeruginosa are prevalent opportunistic bacterial pathogens that cause nosocomial infections in at-risk individuals. The rise of multidrug-resistant P. aeruginosa poses an immense threat to hospitals. Additionally, P. aeruginosa are common food spoilage organisms that contribute to food waste. Alternative effective treatment methods are needed to improve public health and reduce food waste. Recent studies have shown that bacteriophages, viruses that only kill host-specific bacteria, are promising alternatives. This study characterizes two lytic P. aeruginosa phages, ΦPa-C and ΦPa-Tc, and evaluates their efficacy against P. aeruginosa in two model food systems. The morphology, genome, structural proteins, host range, growth kinetics, …

Characterization And Evaluation Of Bacteriophages Φpa-C And Φpa-Tc Infecting Pseudomonas Aeruginosa, Joanne Harrison

Master's Theses

Pseudomonas aeruginosa are prevalent opportunistic bacterial pathogens that cause nosocomial infections in at-risk individuals. The rise of multidrug-resistant P. aeruginosa poses an immense threat to hospitals. Additionally, P. aeruginosa are common food spoilage organisms that contribute to food waste. Alternative effective treatment methods are needed to improve public health and reduce food waste. Recent studies have shown that bacteriophages, viruses that only kill host-specific bacteria, are promising alternatives. This study characterizes two lytic P. aeruginosa phages, ΦPa-C and ΦPa-Tc, and evaluates their efficacy against P. aeruginosa in two model food systems. The morphology, genome, structural proteins, host range, growth kinetics, …

Antibiotic-Induced Changes In Efflux Transporter Expression: A Key Factor In Pseudomonas Aeruginosa Biofilm Resistance, Zara Imtiaz, Avinash Chatoo, Will Wang, Weiqi Li, Paramita Basu

Touro College of Pharmacy (New York) Publications and Research

Listed by WHO as an antibiotic-resistant priority pathogen, Pseudomonas aeruginosa(P.A.) is a serious threat in nosocomial infections. Its high antibiotic resistance is attributed to major mechanisms that can be categorized into intrinsic, acquired, and adaptive resistance. This study tests the ability of three commonly used antibiotics to inhibit new biofilm formation and eradicate mature biofilm growth, as well as investigate changes in the expression levels of selected genes coding for multidrug efflux pumps in P.A. planktonic cells and biofilms before and after treatment with antibiotics to provide a conceptual estimate of the activity of the efflux transporters that work to …

Characterizing The Role Of Pa5189 Of Pseudomonas Aeruginosa In Deletion And Overexpression Mutants, Seh Na Mellick

Theses/Capstones/Creative Projects

In the context of rising multidrug resistance in biofilm-forming pathogens like Pseudomonas aeruginosa, this study investigates the role of the understudied transcription factor PA5189 in antibiotic resistance and biofilm formation. PA5189 deletion and overexpression mutants were created in a parent P. aeruginosa strain using pEX18Tc-based recombinant suicide vectors, with genotypic verification of putative triparental conjugants achieved through restriction digestion and PCR. The study revealed that PA5189 overexpression significantly increases resistance to commonly used broad spectrum antibiotics such as ciprofloxacin and imipenem. Additionally, differential expression of PA5189 was found to notably affect biofilm formation, with variations contingent on the nutrient …

Breaking Virulent: The Coincidental Evolution Of Virulence Factors In Bacteria., Rhiannon Emmanuelle Cecil

Electronic Theses and Dissertations

Understanding how innocuous organisms can evolve to be pathogenic to humans is of increasing global concern. Further, understanding how existing pathogens may evolved to be more virulent is also vital to our ability to provide healthcare to people afflicted with diseases that promote chronic bacterial infections, such as cystic fibrosis. With the rise of antibiotic resistance in both bacteria and fungi it is paramount that new therapeutics are identified. Understanding what mutations occur that result in increased virulence in microbes can potentially provide new targets for antimicrobial drugs to combat antibiotic resistance. The Coincidental Evolution Hypothesis is a fundamental hypothesis …

Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke

Electronic Theses and Dissertations

The number of daily bacterial infections is climbing and the CDC explains that this is due to the antibiotic-resistant threat in the United States. Finding a faster way of bacterial identification is necessary as it currently takes 1-4 days for a medical lab to culture and identify bacteria. Photoacoustic flow cytometry (PAFC) can be used as an alternative method resulting in swift identification within an hour (Edgar, 2019). Pseudomonas aeruginosa, cell line PA01, will be coated in up to a few hundred red dyed phages making it detectible by the photoacoustic flow cytometry system. Bacteriophages (phages) are viruses that …

Evaluation Of Bio-Friendly Formulations From Siderophore-Producing Fluorescent Pseudomonas As Biocontrol Agents For The Management Of Soil-Borne Fungi, Fusarium Oxysporum And Rhizoctonia Solani, Gaber Attia Abo-Zaid, Ahmed Salah Abdullah, Nadia Abdel-Mohsen Soliman, Ebaa Ebrahim El-Sharouny, Abdulaziz A. Al-Askar, Yiming Su, Ahmed Abdelkhalek, Soraya Abdel-Fattah Sabry

Civil and Environmental Engineering Faculty Publications

Secretion of siderophores by Pseudomonas aeruginosa F2 and P. fluorescens JY3 was evaluated on chrome azurol S (CAS) agar plates and their inhibitory effect was inspected against Fusarium oxysporum and Rhizoctonia solani. Production of siderophores as biocontrol agents from F2 and JY3 was accomplished in two optimized media. Afterward, cell-free supernatants of the bacterial cultures containing siderophores were used for the preparation of two bio-friendly formulations for the management of F. oxysporum and R. solani under greenhouse conditions. The investigated bacterial isolates, F2 and JY3, showed antagonistic activity in vitro against F. oxysporum and R. solani and produced siderophores …

Causes And Consequences Of Lasr Mutant Selection In Pseudomonas Aeruginosa Populations, Dallas L. Mould

Dartmouth College Ph.D Dissertations

Change is the only constant in life, and these changes, though random in nature, can have consequences. Quorum sensing is heterogeneous in phenotype and prone to negative selection. In P. aeruginosa, the regulator LasR is frequently non-functional in phylogenetically diverse isolates. Through repeated experimental evolution and mathematical modeling, we show that differences in growth enable lasR mutant evolutionary success and this requires a system enabling metabolic choices, known as carbon catabolite repression (or catabolite repression). The differences in catabolite repression between wild type and lasR mutants enable altered metabolite preferences, and the resulting differences in metabolic states enable intraspecies …

The Stringent Response In Pseudomonas Aeruginosa Influences The Phenotypes Controlled By The Gac/Rsm System, Michael Shawn Hooker

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a ubiquitous, opportunistic pathogen that causes acute and chronic infections. Infection is typically initiated via motile and virulent strains. After exposure to stressors, acute infections make both genotypic and phenotypic switches to a chronic, sessile strain. This is due to intricate regulatory networks directing gene expression in response to stressors. One network, GacA/GacS, has been established to control virulence factors. The stringent response of bacteria is mediated by alarmones produced primarily by RelA which responds to starvation.

To study the effect of the stringent response on the virulence switch. A series of experiments were run in both …

The Effects Of Specialized Pro-Resolving Mediator Lipoxin A4 On Pseudomonas Aeruginosa Biofilms And Interactions With Monocytes, Julianne M. Thornton

Graduate School of Biomedical Sciences Theses and Dissertations

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen known as a major cause of hospital-acquired secondary infections, commonly causing chronic respiratory infections in immunocompromised individuals, especially those with cystic fibrosis, and often found in wound infections. P. aeruginosa uses the quorum sensing pathway to readily form protective biofilms, which reduce the efficacy of antibiotics and access by host immune cells to eradicate the pathogen. Specialized pro-resolving mediators (SPMs) are lipids endogenously produced by the host immune response to infection to aid in infection resolution. One SPM, Lipoxin A4 (LxA4), has been shown to be a robust quorum sensing inhibitor.

The …

Identification Of New Substrates From Pseudomonas Aeruginosa Exos, Adam V. Thota

Master's Theses

Pseudomonas aeruginosa is a gram-negative environmental bacterium that uses its intrinsic and acquired antibiotic resistance to infect patients with compromised epithelium, such as cystic fibrosis and burn wounds, and corneal keratitis. In order to cause disease, most strains of P. aeruginosa use the type three secretion system (T3SS) to disrupt cellular signaling and integrity. However, P. aeruginosa may also secrete exotoxins after invading host cells, which prolongs host cell death and maintains an intracellular niche. Of the T3 secreted effector toxins, ExoS, specifically the ADP-ribosyltransferase activity of ExoS, was shown to delay the death of invaded corneal cells, but it …

Prevalence And Evaluation Of Multidrug Resistance Pattern Of Pseudomonas Aeruginosa Among Critical And Non-Critical Areas At A Tertiary Care Hospital Of Multan, Romah Ishfaq, Hubza Ruatt Khan, Mehvish Javeed, Muhammad Ikrama Tanveer, Asma Ashraf

Journal of Bioresource Management

Pseudomonas aeruginosa is an extremely wide spread microorganism linked to nosocomial illnesses. Effective inspection of variations in antimicrobial resistance patterns of P. aeruginosa is vital for selecting suitable antimicrobial drugs for pragmatic treatment. The current research has been performed for assessing antimicrobial sensitivity profile of P. aeruginosa isolated as of a variety of medical specimens collected from critical and non-critical admitted patients of Nishtar Hospital, Multan. The isolates were detected utilizing standard lab practices, as well as the sensitivity was examined employing Kirby-Bauer disk diffusion method corresponding to Clinical and Laboratory Standard Institute (CLSI) recommendations 2019. Out of 373 samples, …

Interrogating Antagonistic Differences Among Pseudomonas Aeruginosa Cdia Alleles, Haotian Yang

Master's Theses

Bacteria are complex social organisms that live within mixed communities where microorganisms compete for limited resources. We studied Contact-Dependent Growth Inhibition (CDI), a particular type of competition mediated by a type 5b, or two-partner, secretion system that is widely spread among Gram-negative bacteria. CdiB and CdiA make up the two-partner secretion system that mediates CDI. CdiB translocates CdiA to the cell surface, and CdiA delivers its C-terminal toxin domain to the target cell. The C-terminal toxin (Tox) domain of CdiA is highly diverse. We studied Tox domains of various Pseudomonas aeruginosa clinical isolates. We found different strains that contain unique …

Genetic Diversity, Distribution, And Genomic Characterization Of Antibiotic Resistance And Virulence Of Clinical Pseudomonas Aeruginosa Strains In Kenya, Shahiid Kiyaga, Cecilia Kyany'a, Angela W. Muraya, Hunter J. Smith, Emma G. Mills, Caleb Kibet, Gerald Mboowa, Lillian Musila

All Peer-Reviewed Publications

Pseudomonas aeruginosa is a leading cause of nosocomial infections worldwide. It can produce a range of debilitating infections, have a propensity for developing antimicrobial resistance, and present with a variety of potent virulence factors. This study investigated the sequence types (ST), phenotypic antimicrobial susceptibility profiles, and resistance and virulence genes among clinical isolates from urinary tract and skin and soft tissue infections. Fifty-six P. aeruginosa clinical isolates were obtained from six medical centers across five counties in Kenya between 2015 and 2020. Whole-genome sequencing (WGS) was performed to conduct genomic characterization, sequence typing, and phylogenetic analysis of the isolates. Results …

Carbapenemase-Producing Pseudomonas Aeruginosa – An Emerging Challenge, Fred C. Tenover, David P. Nicolau, Christian M. Gill

Biology Faculty Publications

Carbapenem-resistant Pseudomonas aeruginosa (CR-PA) is a major healthcare-associated pathogen worldwide. In the United States, 10–30% of P. aeruginosa isolates are carbapenem-resistant, while globally the percentage varies considerably. A subset of carbapenem-resistant P. aeruginosa isolates harbour carbapenemases, although due in part to limited screening for these enzymes in clinical laboratories, the actual percentage is unknown. Carbapenemase-mediated carbapenem resistance in P. aeruginosa is a significant concern as it greatly limits the choice of anti-infective strategies, although detecting carbapenemase-producing P. aeruginosa in the clinical laboratory can be challenging. Such organisms also have been associated with nosocomial spread requiring infection prevention interventions. The carbapenemases …

Copper(Ii) And Silver(I)‑1,10‑Phenanthroline‑5,6‑Dione Complexes Interact With Double‑Stranded Dna: Further Evidence Of Their Apparent Multi‑Modal Activity Towards Pseudomonas Aeruginosa, Anna Clara Milesi Galdino, Lívia Viganor, Matheus Mendonça Pereira, Michael Devereux, Malachy Mccann, Marta Helena Branquinha, Zara Molphy, Sinéad O'Carroll, Conor Bain, Georgia Menounou, Andrew Kellett, André Luis Souza Dos Santos

Articles

Tackling microbial resistance requires continuous efforts for the development of new molecules with novel mechanisms of action and potent antimicrobial activity. Our group has previously identified metal-based compounds, [Ag(1,10-phenanthroline-5,6-dione)2]ClO4 (Ag-phendione) and [Cu(1,10-phenanthroline-5,6-dione)3](ClO4)2.4H2O (Cu-phendione), with efficient antimicrobial action against multidrug-resistant species. Herein, we investigated the ability of Ag-phendione and Cu-phendione to bind with double-stranded DNA using a combination of in silico and in vitro approaches. Molecular docking revealed that both phendione derivatives can interact with the DNA by hydrogen bonding, hydrophobic and electrostatic interactions. Cu-phendione exhibited the highest binding affinity to either major (− 7.9 kcal/mol) or minor (− 7.2 kcal/mol) …

Phenotypic/Genotypic Profile Of Oxa-10-Like-Harboring, Carbapenem-Resistant Pseudomonas Aeruginosa: Using Validated Pharmacokinetic/Pharmacodynamic In Vivo Models To Further Evaluate Enzyme Functionality And Clinical Implications, Fred C. Tenover, Christian M. Gill, Adrian Brink, Chun Yat Chu, Jennifer Coetzee, George Dimopoulos, Clinton Moodley, Christoffel Johannes Opperman, Spyros Pournaras, Isabella A. Tickler, Hafsah Deepa Tootla, Sophia Vourli, David P. Nicolau

Biology Faculty Publications

In vitro MICs and in vivo pharmacodynamics of ceftazidime and cefepime human-simulated regimens (HSR) against modified carbapenem inactivation method (mCIM)-positive Pseudomonas aeruginosa isolates harboring different OXA-10-like subtypes were described. The murine thigh model assessed ceftazidime (2 g every 8 h [q8h] HSR) and cefepime (2 g and 1 g q8h HSR). Phenotypes were similar despite possessing OXA-10-like subtypes with differing spectra. Ceftazidime produced ≥1-log10 killing in all isolates. Cefepime activity was dose dependent and MIC driven. This approach may be useful in assessing the implications of β-lactamase variants.

Lipoxin A 4 (Lxa 4 ) Promotes Reduction And Antibiotic Efficacy Against Pseudomonas Aeruginosa Biofilm, Julianne M. Thornton, Jean Walker, Prem Yugandhar Kadiyam Sundarasivarao, Bernd Spur, Ana Rodriguez, Kingsley Yin

Rowan-Virtua Research Day

Pseudomonas aeruginosa (P aeruginosa) is an opportunistic bacterium commonly found in wound infections and airways of cystic fibrosis patients P aeruginosa readily forms biofilms which can reduce the efficacy of antibiotics used to eradicate the pathogen We have previously shown that a Specialized Pro resolving Mediator ( Lipoxin A 4 (LxA 4 is a quorum sensing inhibitor which can reduce P aeruginosa virulence In this study, we examined the direct actions of LxA 4 and RvD 2 on P aeruginosa biofilm formation and virulence gene expression The influence of LxA 4 on antibiotic efficacy and the combined effects on biofilm …

Ecological, Evolutionary, And Molecular Mechanisms Driving Pyocin Diversity In Pseudomonas Aeruginosa., Aubrey A. Mojesky

Electronic Theses and Dissertations

Bacteriocins are narrow-spectrum antibiotics produced in nearly all lineages of bacteria, meaning that these antimicrobials target closely related individuals. The bacteriocins of Pseudomonas aeruginosa, called pyocins, are highly prevalent and diverse in populations of this species. Laboratory studies have shown that pyocins can function to mediate the outcome of interactions, often allowing for the coexistence of multiple strains, as no one pyocin genotype is competitively superior. Although this has been demonstrated under laboratory conditions, the function of pyocins in natural settings and the ecological, evolutionary, and genetic mechanisms underlying pyocin diversity remains unclear. As such, for my dissertation, I …

Evaluation Of The Xpert Carba-R Nxg Assay For Detection Of Carbapenemase Genes In A Global Challenge Set Of Pseudomonas Aeruginosa Isolates, Fred C. Tenover, Christian M. Gill, Tomefa E. Asempa, Isabella A. Tickler, Caitlin M. Dela Cruz, David P. Nicolau

Biology Faculty Publications

The growing prevalence and diversity of carbapenemase producers among carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates warrants an expansion of detection capabilities. The purpose of this study was to evaluate the performance of the commercially available Xpert Carba-R (Carba-R) and the research-use-only Xpert Carba-R NxG (Carba-R NxG) in a global collection of P. aeruginosa. The challenge set included 123 P. aeruginosa clinical isolates from 12 countries. Isolates were previously categorized via PCR or whole-genome sequencing. Carbapenemase classes tested include VIM, IMP, NDM, SPM, KPC, and GES. Non-carbapenemase (non-CP)-harboring isolates were also tested (negative control). Isolates were tested using the Carba-R NxG and …

Disruption Of Pyoverdine Synthesis In Pseudomonas Aeruginosa Through Periodic Disturbance Of Biofilm Structure, Rebecca J. Quinn

All HCAS Student Capstones, Theses, and Dissertations

Infections due to bacteria were once easily treated using antibiotics. However, the effective shelf life of antibiotics is diminishing due to the rise and spread of antibiotic resistant bacteria. Accordingly, novel approaches to treating infections are required. Pseudomonas aeruginosa is a multi-drug resistant, biofilm forming opportunistic pathogen. A determinant of P. aeruginosa’s pathogenicity is pyoverdine, a siderophore that is used to sequester iron from the environment. After being produced by a bacterium, pyoverdine is secreted into the environment where it complexes with iron. The pyoverdine-iron complex is then returned to the bacteria through diffusion, where it drives the synthesis of …

The Effects Of Nutrient Availability On Pseudomonas Aeruginosa Mono And Co-Culture Biofilms, Julie T. Nguyen, Deborah R. Yoder-Himes Ph.D., Rhiannon Cecil

Undergraduate Arts and Research Showcase

Cystic Fibrosis (CF) is a genetic disorder characterized by faulty ion channels and result in thick mucus accumulation, especially in lungs. Mucus buildup provides ideal conditions for bacterial infections. Pseudomonas aeruginosa (PA) is the second most prevalent bacterium isolated from people with CF and has a high clinical importance. Most CF pathogens form biofilms which make treatment of infections difficult. Biofilms are clusters of cells attached to a surface enclosed in a structured matrix. These structures are a means to provide shelter for bacteria from the environment, especially antibiotics and the immune system. PA alone can form these biofilms, but …

The Pseudomonas Aeruginosa Interactome: Insights Into Srna-Mediated Regulatory Networks, Christine M. Van Duyn

Theses and Dissertations

Pseudomonas aeruginosa is a Gram-negative bacterium found in various environmental niches including soil, water, hospital environments, and within a broad range of hosts. It is well known for its metabolic versatility and intrinsic and acquired resistance to a variety of antimicrobial agents. Moreover, this bacterium has a remarkable ability to adapt and survive in suboptimal environments by altering its transcriptional profile in response to nutrient deprivation, changes in temperature and pH, osmotic stress, the presence of reactive oxygen species (ROS), and exposure to antibiotics and host defenses. P. aeruginosa colonizes individuals with compromised immune systems and severe burn injuries and …

The Antimicrobial Activity And Cellular Pathways Targeted By P-Anisaldehyde And Epigallocatechin Gallate In The Opportunistic Human Pathogen Pseudomonas Aeruginosa, Yetunde Adewumni, Sanchirmaa Namjilsuren, William D. Walker, Dahlia N. Amato, Douglas V. Amato, Olga V. Mavrodi, Derek L. Patton, Dmitri V. Mavrodi

Faculty Publications

Plant-derived aldehydes are constituents of essential oils that possess broad-spectrum antimicrobial activity and kill microorganisms without promoting resistance. In our previous study, we incorporated p-anisaldehyde from star anise into a polymer network called PANDAs (Pro-Antimicrobial Networks via Degradable Acetals) and used it as a novel drug delivery platform. PANDAs released p-anisaldehyde upon a change in pH and humidity, and controlled growth of the multi-drug resistant pathogen Pseudomonas aeruginosa PAO1. In this study, we identified cellular pathways targeted by p-anisaldehyde, by generating 10,000 transposon mutants of PAO1 and screened them for hypersensitivity to p-anisaldehyde. To improve the …

The Importance Of Rnd-Type Efflux Pumps In The Interactions Of Pseudomonas Aeruginosa With 4-Methoxybenzaldehyde, Sanchirmaa Namjilsuren

Honors Theses

Pseudomonas aeruginosa is a common hospital-acquired pathogen and is often associated with high mortality rates due to the development of multidrug-resistance. Antimicrobial plant-derived (phyto-) aldehydes present a promising alternative to antibiotics due to their broad-spectrum antimicrobial activity and low propensity to trigger resistance. However, two main problems preclude the widespread application of these compounds: chemical instability and low antimicrobial efficacy. The ongoing collaboration between the Mavrodi and Patton labs at USM has recently addressed the problem of chemical instability by incorporating plant aldehydes into polymer materials called Pro-Antimicrobial Networks via Degradable Acetals (PANDAs). Thus, this study aimed to address the …

Iron-Containing Nanoparticles For The Treatment Of Chrionic Biofilm Infections In Cystic Fibrosis, Leisha M. A. Martin

Nanoscience and Microsystems ETDs

Cystic fibrosis (CF) is the most common genetic disease resulting in the morbidity and mortality of Caucasian children and adults worldwide. Due to a genetic mutation resulting in malfunction of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, CF patients produce highly viscous mucus in their respiratory tract. This leads to impairment of the mucociliary clearance of inhaled microbes. In addition to reduced microbial clearance, anoxic environmental conditions in the lungs promote biofilm-mode growth of the pathogenic bacterial species Pseudomonas aeruginosa. Chronic infections of P. aeruginosa begin in early childhood and typically persist until respiratory failure and death result. The …