Organisms Commons^™

An Epidemiological And Pharmacokinetic-Pharmacodynamic Investigation Into The Impact Of Carbapenem-Resistant Enterobacterales, Justin Clark

Theses and Dissertations--Pharmacy

Background: According to the 2019 CDC Antibiotic Resistance Threats Report, more than 2.8 million antibiotic-resistant infections occur in the United States each year, leading to more than 35,000 deaths. Among the most urgent threats identified by the CDC are carbapenem-resistant Enterobacterales (CRE). Despite efforts to control the spread of these organisms, the number of estimated cases between 2012 and 2017 remained stable. In 2017, an estimated 13,100 hospitalized cases of CRE led to approximately 1,100 deaths and $130 million attributable healthcare costs. This dissertation seeks to address this issue from both a pharmacokinetic/pharmacodynamic and epidemiological perspective.

Methods: We evaluated the …

Extensively Drug-Resistant Pseudomonas Aeruginosa In Vitro Susceptibility And Mechanisms Of Resistance, Chanah Gallagher

Theses and Dissertations--Pharmacy

Pseudomonas aeruginosa causes severe healthcare-associated infections. Forty-eight extensively drug-resistant (XDR)-P. aeruginosa isolates were selected from 287 isolates collected for evaluation based on clinical susceptibility data. In vitro activity of commonly utilized antimicrobials (i.e. antipseudomonal beta-lactams, aminoglycosides, fluoroquinolones, and polymyxins) plus ceftolozane-tazobactam, ceftazidime-avibactam, and aztreonam-avibactam against XDR-P. aeruginosa were determined. The mechanism of resistance profile was determined through phenotypic expression analysis. Overall, polymyxin B and colistin were 100% susceptible. Apart from the polymyxins, ceftolozane-tazobactam had the highest susceptibility (94%) followed by ceftazidime-avibactam (90%) and amikacin (83%). Ceftolozane-tazobactam activity was not significantly different from ceftazidime-avibactam (p=0.6831). Only 40% of isolates …

Novel Small Molecule Antifungals For Invasive Fungal Infections, Emily Dennis

Theses and Dissertations--Pharmacy

Human fungal pathogens cause a range of diseases from benign skin conditions (i.e., ringworm) to thrush, mucosal membrane infections, and life-threatening systemic infections including bloodstream infections (i.e., aspergillosis and candidiasis) and Cryptococcal meningitis. These systemic infections occur most often in immunocompromised individuals and have high mortality rates. Current antifungal agents used in the clinic belong to three main classes: the polyenes (e.g., amphotericin B (AmB)), the echinocandins (e.g., caspofungin (CFG)), and the azoles (e.g., fluconazole (FLC)). In addition, the antimetabolite pyrimidine analogue flucytosine is used in combination with AmB. The …

Spore Forming Actinobacterial Diversity Of Cholistan Desert Pakistan: Polyphasic Taxonomy, Antimicrobial Potential And Chemical Profiling, Adeela Fatima, Usman Aftab, Khaled A. Shaaban, Jon S. Thorson, Imran Sajid

Center for Pharmaceutical Research and Innovation Faculty Publications

Background: Actinobacteria are famous for the production of unique secondary metabolites that help in controlling the continuously emerging drug resistance all over the globe. This study aimed at the investigation of an extreme environment the Cholistan desert, located in southern Punjab, Pakistan, for actinobacterial diversity and their activity against methicillin resistant Staphylococcus aureus (MRSA). The Cholistan desert is a sub-tropical and arid ecosystem with harsh environment, limited rainfall and low humidity. The 20 soil and sand samples were collected from different locations in the desert and the actinobacterial strains were selectively isolated. The isolated strains were identified using a polyphasic …

Phaeophleospora Vochysiae Savi & Glienke Sp. Nov. Isolated From Vochysia Divergens Found In The Pantanal, Brazil, Produces Bioactive Secondary Metabolites, Daiani C. Savi, Khaled A. Shaaban, Francielly M. W. Gos, Larissa V. Ponomareva, Jon S. Thorson, Chirlei Glienke, Jürgen Rohr

Pharmaceutical Sciences Faculty Publications

Microorganisms associated with plants are highly diverse and can produce a large number of secondary metabolites, with antimicrobial, anti-parasitic and cytotoxic activities. We are particularly interested in exploring endophytes from medicinal plants found in the Pantanal, a unique and widely unexplored wetland in Brazil. In a bio-prospecting study, strains LGMF1213 and LGMF1215 were isolated as endophytes from Vochysia divergens, and by morphological and molecular phylogenetic analyses were characterized as Phaeophleospora vochysiae sp. nov. The chemical assessment of this species reveals three major compounds with high biological activity, cercoscosporin (1), isocercosporin (2) and the new compound 3-(sec-butyl)-6-ethyl-4,5-dihydroxy-2-methoxy-6-methylcyclohex-2-enone (3). …

Discovery Of New Antimicrobial Options And Evaluation Of Aminoglycoside Resistance Enzyme-Associated Resistance Epidemic, Selina Y. L. Holbrook

Theses and Dissertations--Pharmacy

The extensive and sometimes incorrect and noncompliant use of various types of antimicrobial agents has accelerated the development of antimicrobial resistance (AMR). In fact, AMR has become one of the greatest global threat to human health in this era. The broad-spectrum antibiotics aminoglycosides (AGs) display excellent potency against most Gram-negative bacteria, mycobacteria, and some Gram-positive bacteria, such as Staphylococcus aureus. The AG antibiotics amikacin, gentamicin, kanamycin, and tobramycin are still commonly prescribed in the U.S.A. for the treatment of serious infections. Unfortunately, bacteria evolve to acquire resistance to AGs via four different mechanisms: i) changing in membrane permeability to …

Synthesis And Biological Evaluation Of Novel Drug Candidates To Address Drug Resistance In Tuberculosis And Fungal Diseases, Huy Ngo

Theses and Dissertations--Pharmacy

Tuberculosis (TB) and fungal infections are two of the most lethal infectious diseases worldwide due to the emergence of drug-resistant Mycobacterium tuberculosis (Mtb) and fungal strains that can resist the most potent antimicrobial drugs currently employed. Due to the rise of these drug resistant strains, effective treatment options for these two infections are limited. This dissertation aims at exploring novel drug scaffolds to help combat drug resistance in TB and fungal infections.

TB caused by the pathogenic Mtb is, alongside with human immunodeficiency virus acquired immunodeficiency virus (HIV), the deadliest infectious disease worldwide with approximately 2-3 billion people …

Antibacterial Activity Of Endophytic Actinomycetes Isolated From The Medicinal Plant Vochysia Divergens (Pantanal, Brazil), Francielly M. W. Gos, Daiani C. Savi, Khaled A. Shaaban, Jon S. Thorson, Rodrigo Aluizio, Yvelise M. Possiede, Jürgen Rohr, Chirlei Glienke

Pharmaceutical Sciences Faculty Publications

Endophytic actinomycetes from medicinal plants produce a wide diversity of secondary metabolites (SM). However, to date, the knowledge about endophytes from Brazil remains scarce. Thus, we analyzed the antimicrobial potential of 10 actinomycetes isolated from the medicinal plant Vochysia divergens located in the Pantanal sul-mato-grossense, an unexplored wetland in Brazil. Strains were classified as belonging to the Aeromicrobium, Actinomadura, Microbacterium, Microbispora, Micrococcus, Sphaerisporangium, Streptomyces, and Williamsia genera, through morphological and 16S rRNA phylogenetic analyzes. A susceptibility analysis demonstrated that the strains were largely resistant to the antibiotics oxacillin and nalidixic acid. Additionally, different culture media (SG and R5A), and …

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 …