Microbiology Commons^™

Antibiotic-Resistant Escherichia Coli From Retail Poultry Meat With Different Antibiotic Use Claims, Gregg S. Davis, Kara Waits, Lora Nordstrom, Heidi Grande, Brett Weaver, Katerina Papp, Joseph Horwinski, Benjamin Koch, Bruce A. Hungate, Cindy M. Liu, Lance B. Price

Civil and Environmental Engineering and Construction Faculty Research

Background We sought to determine if the prevalence of antibiotic-resistant Escherichia coli differed across retail poultry products and among major production categories, including organic, “raised without antibiotics”, and conventional. Results We collected all available brands of retail chicken and turkey—including conventional, “raised without antibiotic”, and organic products—every two weeks from January to December 2012. In total, E. coli was recovered from 91% of 546 turkey products tested and 88% of 1367 chicken products tested. The proportion of samples contaminated with E. coli was similar across all three production categories. Resistance prevalence varied by meat type and was highest among E. …

Self-Resistance During Muraymycin Biosynthesis: A Complementary Nucleotidyltransferase And Phosphotransferase With Identical Modification Sites And Distinct Temporal Order, Zheng Cui, Xia-Chang Wang, Xiaodong Liu, Anke Lemke, Stefan Koppermann, Christian Ducho, Jürgen Rohr, Jon S. Thorson, Steven G. Van Lanen

Pharmaceutical Sciences Faculty Publications

Muraymycins are antibacterial natural products from Streptomyces spp. that inhibit translocase I (MraY), which is involved in cell wall biosynthesis. Structurally, muraymycins consist of a 5′-C-glycyluridine (GlyU) appended to a 5″-amino-5″-deoxyribose (ADR), forming a disaccharide core that is found in several peptidyl nucleoside inhibitors of MraY. For muraymycins, the GlyU-ADR disaccharide is further modified with an aminopropyl-linked peptide to generate the simplest structures, annotated as the muraymycin D series. Two enzymes encoded in the muraymycin biosynthetic gene cluster, Mur29 and Mur28, were functionally assigned in vitro as a Mg·ATP-dependent nucleotidyltransferase and a Mg·ATP-dependent phosphotransferase, respectively, both modifying the …

Isolation, Sequencing, And Characterization Of Four Transmissible Antibiotic Resistance Plasmids Captured From Bacteria In Stream Sediments, Curtis J. Kapsak

Masters Theses, 2010-2019

Self-transmissible plasmids are key vectors in the transfer of resistance, catabolic, and other genes among bacteria native to environments such as streams and wetlands. The evolution of antibiotic resistance in particular is known to be powerfully affected by conjugative plasmid transfer due to the ease in which some plasmids can be horizontally transferred into a broad range of host bacteria and their ability to exchange mobile genetic elements that often contain antibiotic resistance genes.

In this study, we captured tetracycline resistance plasmids from stream sediments impacted by agricultural runoff. We selected for resistance plasmids using tetracycline, an antibiotic commonly used …

Antibiotic Resistant Bacteria In Water Environments In Louisville, Kentucky., Amy Priest

College of Arts & Sciences Senior Honors Theses

Antibiotic resistant bacterial strains are an increasing problem, particularly in clinical health care settings. As a result, bacterial infections are becoming increasingly challenging to treat with more cases becoming life threatening. Aquatic environments facilitate microbial diversity and the transfer of genetic elements and thus may serve as a reservoir for antibiotic resistant microbes. Human misuse of antibiotics may further facilitate the spread of resistance in water environments. With little known about the bacteria communities in local water environments, this study aimed to learn more about these populations through the following aims: 1) identify the microbial community composition from water environments …

Trends In Antibiotic Resistance And Correlations Of Antibiotic Use And Antibiotic Resistance In A Small Hospital In El Paso, Texas 2013-2015, Christopher Olivas

Open Access Theses & Dissertations

Antibiotic resistance is a serious public health threat, primarily, resulting from the excess and inappropriate use of antibiotics. Antibiotic resistance and antibiotic consumption trends may differ along the U.S-Mexico border from the rest of the U.S. due to geographical and cultural differences unique to the border region. The objectives of this study were: 1.) To examine the trends in antibiotic resistance among E. coli, ESBL producing E. coli, P. aeruginosa, S. aureus, and MRSA over a 3-year period (2013, 2014, 2015) in a U.S.-Mexico border area hospital; 2.) To examine the trends in antibiotic consumption among aztreonam, cefazolin, cefepime, ceftriaxone, …

An Interdisciplinary Approach To The Target Elucidation Of Novel Antibiotic 31g12, Larissa A. Walker

Graduate Student Theses, Dissertations, & Professional Papers

Staphylococcus aureus is a Gram-positive bacterial pathogen responsible for nosocomial and community-acquired infections that can quickly acquire antibiotic resistance. We have identified a novel triazole antimicrobial 31G12 based on the natural product core of nonactin isolated from the fermentation of Streptomyces griseus, that is active against many Gram-positive bacteria as well as antibiotic resistant methicillin-resistant S. aureus and vancomycin-resistant Enterococcus. The synthesis and characterization indicate that 31G12 exists as a mixture of two rotamers at room temperature and displays bacteriostatic activity against S. aureus with moderate mammalian cell toxicity. We have currently identified potential protein targets of 31G12 in …