Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"β-lactam resistance"”.
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Antibiotic resistance in the gut microbiota
Antibiotic resistance is an increasing threat to our ability to treat infectious diseases. Thus, understanding the effects of antibiotics on the gut microbiota, as well as the potential for such populations to act as a reservoir for resistance genes, is imperative. This thesis set out to …
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Beyond MICS: Determining the Role of Porin Production and β-Lactamase Expression in Resistance and Cellular Physiology of Klebsiella pneumoniae
Background: K. pneumoniae is capable of resistance to β-lactam antibiotics through expression of β-lactamases and downregulation of outer membrane porins. However, the extent to which these mechanisms interplay in a resistant phenotype is not well understood. β-lactamase expression has long been …
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Structural characterization of superbug proteins involved in regulating beta-lactam resistance
The widespread use of β-lactams has undermined their effectiveness as chemotherapeutic agents by fueling the evolution and dissemination of multiple resistance mechanisms, including: (1) production of hydrolytic β-lactamase enzymes that inactivate β-lactams, (2) expression of PBPs with …
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GENOMIC SURVEILLANCE AND RISK-BASED ASSESSMENT OF ANTIBIOTIC RESISTANCE TRANSMISSION ACROSS TROPICAL AQUATIC ENVIRONMENTS
Antimicrobial resistance (AMR) transmitted through aquatic environments poses a growing public health threat, yet the genomic mechanisms governing resistance gene flow across interconnected water systems remain poorly understood. This thesis investigates β-lactam resistance transmission across …
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Mechanisms Involved in the Expression of the AmpC Beta-lactamase Gene blaCMY-2 in Escherichia coli
… that express plasmid-encoded AmpC β-lactamases can be resistant to third generation cephalosporins and β-lactam/β-lactamase inhibitor combinations. Infections by these bacteria are associated with increased patient morbidity and mortality. Little is known about how plasmid-encoded …
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Outer Membrane Porin Regulation among Different Sequence Types of Escherichia coli Clinical Isolates
… pandemic clone associated with the spread of β-lactam and fluoroquinolone resistance. However, the reasons for the global dominance of this clone are largely unknown. It has been suggested that the success of ST131 E. coli is due to the resistance and virulence genes it possesses. Additionally, …
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Elucidation of the Molecular Mechanisms That Contribute to Variation in Susceptibility Testing Show the Need for Alternative Detection Methods of KPC-producing Gram-negative Bacteria
… have been associated with high levels of β- lactam resistance, in addition to other antibiotic drug classes. This, in addition to the lack of novel antimicrobials with activity against Gram-negative bacteria, forces physicians to treat infections caused by KPC-producing pathogens with …
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Insights Into Determinants That Contribute to Colonization, Virulence and Antibiotic Resistance In Enterococci
… are very difficult to treat due to multi-drug resistance. The work presented in the first part of this dissertation elucidates a mechanism for the regulation of pilus expression. I showed that ATT is the initiation codon of <em>ebpA</em>, the first gene of an operon that codes for the …
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Invasive disease by Haemophilus influenzae in Sweden in the era of the H. influenzae type b vaccine
… the clinical burden and antimicrobial resistance of invasive H. influenzae in Sweden 1997-2010. Two aspects of the pathogenesis of invasive H. influenzae disease were addressed; bacterial binding to the extracellular matrix and the role of complement regulator binding in invasive …
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Characterization Of Antimicrobial-Resistant staphylococcus Spp. In Food Animals And Retail Meat
<p>Antimicrobial resistance in <i>Staphylococcus</i> spp. is a worldwide epidemic concern in hospital and community settings. Food animals and retail meat are important reservoirs of these pathogens that can pose potential threat to humans. In this dissertation, we aimed to investigate the …
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Evaluation of the Interplay between β-Lactamase Expression and Porin Loss in β-Lactam Susceptibility Profiles in Escherichia coli
… has shown a marked increase in antimicrobial resistance driven by the acquisition of Extended-Spectrum β-Lactamases (ESBLs) and carbapenemases. However, β-lactam resistance in E. coli is often multifactorial, arising from different mechanisms such as the combined effects of β-lactamase …
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Cell wall metabolite levels as a function of the growth phase in Staphylococcus aureus and library screening for synergistic combinations of FDA approved drugs against methicillin resistant S. aureus
… agents. Strongly synergistic agents included β-lactamase resistant β-lactams (cloxacillin, dicloxacillin, flucloxacillin, oxacillin, nafcillin, and cefotaxime). There was also evidence of synergy between ceftobiprole and both meropenem and imipenem. Vancomycin, balofloxacin, and floxuridine …