Bacteria Commons^™

What? Now A Respiratory Syncytial Virus Epidemic, Aya Allam, Steven B Lippmann

The University of Louisville Journal of Respiratory Infections

No abstract provided.

Implementation Of Mrsa Nasal Swabs As An Antimicrobial Stewardship Intervention To Decrease Anti-Mrsa Therapy In Covid-19 Infection, Alaina Dekerlegand, Emily Johnston, Britney Mellor, Melanie Rae Schrack, Catherine O’Neal

School of Medicine Faculty Publications

In the early stages of treating patients with SARS-CoV-2, limited information was available to guide antimicrobial stewardship interventions. The COVID-19 Task Force and Antimicrobial Stewardship Committee, at a 988-bed academic medical center, implemented the use of methicillin-resistant Staphylococcus aureus (MRSA) nasal swab polymerase chain reaction (PCR) testing to assist with the de-escalation of anti-MRSA therapy in patients with suspected superimposed bacterial pneumonia in COVID-19. A retrospective study was conducted to evaluate the impact of MRSA nasal swab PCR testing on the rate of anti-MRSA therapy between 13 April 2020 and 26 July 2020. A total of 122 patients were included …

Population Genomics Of Australian Indigenous Mesorhizobium Reveals Diverse Nonsymbiotic Genospecies Capable Of Nitrogen-Fixing Symbioses Following Horizontal Gene Transfer, Elena Colombi, Yvette Hill, Rose Lines, John T. Sullivan, Maclean G. Kohlmeier, Claus T. Christophersen, Clive W. Ronson, Jason J. Terpolilli, Joshua P. Ramsay

Research outputs 2022 to 2026

Mesorhizobia are soil bacteria that establish nitrogen-fixing symbioses with various legumes. Novel symbiotic mesorhizobia frequently evolve following horizontal transfer of symbiosis-gene-carrying integrative and conjugative elements (ICESyms) to indigenous mesorhizobia in soils. Evolved symbionts exhibit a wide range in symbiotic effectiveness, with some fixing nitrogen poorly or not at all. Little is known about the genetic diversity and symbiotic potential of indigenous soil mesorhizobia prior to ICESym acquisition. Here we sequenced genomes of 144 Mesorhizobium spp. strains cultured directly from cultivated and uncultivated Australian soils. Of these, 126 lacked symbiosis genes. The only isolated symbiotic strains were either exotic strains used …

Using Nspefs To Sensitize Mrsa To Vancomycin Treatment, Areej Malik, Alexandra E. Chittams-Miles, Claudia Muratori, Erin B. Purcell

The Graduate School Posters

Staphylococcus aureus (S. aureus) is a biofilm-forming pathogen. S. aureus treatment is marked by the development of antibiotic resistance. The public health impact has increased since the emergence of methicillin-resistant S. aureus (MRSA), which has started to show intermediate resistance to vancomycin in MRSA. Nano-second pulse electric fields (nsPEFs) are low-energy and high-power electric pulses, which have been suggested to sensitize pathogens to antibiotics by creating transient pores in the cell membrane. Our combinatorial treatment includes nsPEF pre-treatment and vancomycin post-treatment of MRSA cells. Our results show that MRSA log phase cells had the highest susceptibility to vancomycin. …

Extracting High-Molecular Weight Dna From Cyanobacteria Using Promega's Wizard® Hmw Dna Extraction Kit With A Modified Protocol, Metis, Megan A. Hept, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

Extraction of high molecular weight (HMW) DNA for long read sequencing with little to no fragmentation and high purity is difficult to acquire from cyanobacterial species. Here we describe a modified method of extraction using Promega's Wizard® HMW DNA Extraction Kit to acquire high molecular weight DNA from cyanobacterial species. The protocol used in the kit is the “3.D. Isolating HMW DNA from Gram-Positive and Gram-Negative Bacteria” protocol. During a key step in the protocol, the lingering remnants of the mucilage layer of the cyanobacterial species is removed, preventing it from sticking to the DNA pellet produced. This customized modification …

Studying Gene Function In Streptococcus Sanguinis Using Rna-Sequencing Analysis, Ahmed Ismail

Theses and Dissertations

The oral cavity hosts hundreds of bacterial species, amongst them are the Streptococci family. More specifically, S. sanguinis is a benign bacteria in the oral cavity to protect the tooth surface from S. mutans. which is a pathogen causing dental caries. While S. sanguinis is harmless in the oral cavity, it becomes pathogenic once entering the bloodstream and causing Infective Endocarditis (IE). To further study S. sanguinis and eventually develop an effective drug to treat IE caused by S. sanguinis, a gene expression study was conducted. In order to study gene expression, RNA-sequencing was conducted, and appropriate methods to remove …

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 …

Alzheimer’S Disease Genetics And Short-Chain Fatty Acid Treatment In Studies Of The Murine Gut Microbiome, Diana Zajac

Theses and Dissertations--Physiology

Elucidating the relationship of the gut microbiome in Alzheimer's Disease (AD) risk and pathogenesis is an area of intense interest. Since 60 to 80% of AD risk is related to genetics and APOE alleles represent the most impactful genetic risk factors for AD, their mechanism(s) of action are under intense scrutiny.

First, I conducted a study on APOE targeted replacement mice to investigate the impact of APOE alleles on the murine gut microbiome. The relative abundance of bacteria from the family Ruminococacceae and related genera increased with APOE2 status. The relative abundance of the class Erysipelotrichia increased with APOE4 status, …

A Global Comparison Of Marine Chlorophyll Variability Observed In Eulerian And Lagrangian Perspectives, Angela M. Kuhn, Matthew Mazloff, Stephanie Dutkiewicz, Oliver Jahn, Sophie Clayton, Tatiana Rynearson, Andrew D. Barton

OES Faculty Publications

The California Current System is a diatom‐dominated region characterized by seasonal coastal upwelling and additional elevated mesoscale activity. Cyclonic mesoscale eddies in the region trap productive coastal waters with their planktonic communities and transport them offshore with limited interaction with surrounding waters, effectively acting as natural mesocosms, where phytoplankton populations undergo ecological succession as eddies age. This study examines diatom community composition within two mesoscale cyclonic eddies that formed in the same region of the California Current System 2 months apart and in the California Current waters surrounding them. The diatom communities were analyzed in the context of shifting environmental …

Expansion On The Use Of The Novel Compound, Elp-004, Using A Mycobacterium Tuberculosis Experimentation Model, Kendyl Marie Berry

Graduate Theses, Dissertations, and Problem Reports (ETD)

Osteoarticular tuberculosis (OAT) is a bone degenerative disease that results in bone erosion, joint effusion, joint swelling, and sometimes, nerve compression. OAT occurs from the hematogenous dissemination of Mycobacterium tuberculosis (Mtb) bacilli spreading from the primary site of infection to the bones and joints; the primary site of infection tends to be the lungs as pulmonary tuberculosis infections are the most common. OAT can occur as the result of an active or latent infection. Latent infections result in OAT when bacilli are able to escape granulomas. The incidence of OAT is not as high as pulmonary infections, making up about …

Development Of A Chemical Biology Approach To Uncover The Influence Of Sequence Variations On Ces1 Activity In Live Cells, Samuel James Knebel

Masters Theses

Drug metabolism is the biochemical process of modifying drugs to detoxify and remove them through enzymatic transformations. These biotransformation’s occur primarily in the liver and are critical to understanding how pharmaceutical compounds are chemically altered inside the human body. Human carboxylesterases (CESs) catalyze the hydrolysis of esters, amides, thioesters, and carbamates. CES-mediated hydrolysis plays an important role in the metabolism of many drugs including the first FDA approved antiviral treatment for COVID-19, remdesivir (Veklury), the seizure control medication rufinamide (Banzel), and the flu antiviral drug oseltamivir (Tamiflu). CES activity is known to be influenced by a variety of factors including …

Exploring The Effects Of Fatty Acids (Pufas) On The Antimicrobial Resistance In Vibrio Cholerae, Naina Patel

Honors Theses

As antibiotic resistance becomes a major challenge for public health professionals, our research objectives aimed to investigate the potential for polyunsaturated fatty acids (PUFAs) to create membrane vulnerability in the gram-negative pathogen Vibrio cholerae to help improve the efficacy of several antibiotics. V. cholerae, normally residing in aquatic environments, is capable of altering its phospholipid composition through the uptake and assimilation of exogenous polyunsaturated fatty acids. The purpose of this study was to measure PUFA-mediated changes in the membrane permeability and antibiotic resistance of Vibrio cholerae. The three physiologically relevant PUFAs used were linoleic acid [18:2], arachidonic acid [20:4], and …

Oxidative Stress Strongly Restricts The Effect Of Codon Choice On The Efficiency Of Protein Synthesis In Escherichia Coli, Lorenzo Eugenio Leiva, Sara Elgamal, Sebastian A. Leidel, Omar Orellana, Michael Ibba, Assaf Katz

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Introduction

The response of enterobacteria to oxidative stress is usually considered to be regulated by transcription factors such as OxyR and SoxR. Nevertheless, several reports have shown that under oxidative stress the levels, modification and aminoacylation of tRNAs may be altered suggesting a role of codon bias in regulation of gene expression under this condition.

Methods

In order to characterize the effects of oxidative stress on translation elongation we constructed a library of 61 plasmids, each coding for the green fluorescent protein (GFP) translationally fused to a different set of four identical codons.

Results

Using these reporters, we observed that …

The Antimicrobial Resistance Crisis Needs Action Now, Nonia Pariente

Research on Antimicrobial Resistance

Antimicrobial resistance is a global problem of increasing proportions that we cannot afford to look away from. This World Antimicrobial Awareness Week, we shine a light on the crisis and ways we can all help to address it.

Sea-Phages Research Opportunity, Sarah Ballarin

Trick to the Treat of Internships and Research

Research opportunity targeted for freshmen and sophomores through the SEA-PHAGES program. The goal of the research is to discover new bacteriophages (viruses that infect bacteria) to help combat antibiotic resistance. Phage therapy is a promising alternative to conventional antibiotics. Phages have also been widely used in the food industry to prevent microbial growth on certain foods and are currently being explored as a method for bioremediation of oil spills and wastewater treatment.

Last year, my research team discovered two new bacteriophages: Genamy16 and NovaSharks that were able to infect the bacteria Gordonia rubripertincta. These phages can possibly be used for …

What? Is Epstein–Barr Virus Infection Linked To Multiple Sclerosis?, Asha Mahajan, Steven B Lippmann

The University of Louisville Journal of Respiratory Infections

No abstract provided.

Emergence Of A Multidrug-Resistant And Virulent Streptococcus Pneumoniae Lineage Mediates Serotype Replacement After Pcv13: An International Whole-Genome Sequencing Study, Stephanie W. Lo, Kate Mellor, Robert Cohen, Alba Redin Alonso, Sophie Belman, Narender Kumar, Paulina A. Hawkins, Rebecca A. Gladstone, Sadia Shakoor, Muhammad Imran Nisar

Department of Pathology and Laboratory Medicine

Background: Serotype 24F is one of the emerging pneumococcal serotypes after the introduction of pneumococcal conjugate vaccine (PCV). We aimed to identify lineages driving the increase of serotype 24F in France and place these findings into a global context.
Methods: Whole-genome sequencing was performed on a collection of serotype 24F pneumococci from asymptomatic colonisation (n=229) and invasive disease (n=190) isolates among individuals younger than 18 years in France, from 2003 to 2018. To provide a global context, we included an additional collection of 24F isolates in the Global Pneumococcal Sequencing (GPS) project database for analysis. A Global Pneumococcal Sequence Cluster …

Do You Know The Pathophysiology Of Cytokine Storm During Covid-19?, Shameera Shaik Masthan, Deekshitha Turaka, Ahmed Abdelhaleem, Mounica Vorla, Steven B. Lippmann

The University of Louisville Journal of Respiratory Infections

No abstract provided.

Frequency Of Bystander Exposure To Antibiotics For Enteropathogenic Bacteria Among Young Children In Low-Resource Settings, Elizabeth T. Rogawski Mcquade, Stephanie A. Brennhofer, Sarah E. Elwood, Timothy L. Mcmurry, Joseph A. Lewnard, Estomih R. Mduma, Sanjaya Shrestha, Najeeha Talat Iqbal, Pascal O. Bessong, Gagandeep Kang

Department of Paediatrics and Child Health

Children in low-resource settings carry enteric pathogens asymptomatically and are frequently treated with antibiotics, resulting in opportunities for pathogens to be exposed to antibiotics when not the target of treatment (i.e., bystander exposure). We quantified the frequency of bystander antibiotic exposures for enteric pathogens and estimated associations with resistance among children in eight low-resource settings. We analyzed 15,697 antibiotic courses from 1,715 children aged 0 to 2 y from the MAL-ED birth cohort. We calculated the incidence of bystander exposures and attributed exposures to respiratory and diarrheal illnesses. We associated bystander exposure with phenotypic susceptibility of E. coli isolates in …

Generation Of Mycobacterium Smegmatis Model Systems For Testing Inhibitors Of The Mycobactin Siderophore Of Mycobacterium Tuberculosis, Gabrielle A. Germain

Dissertations, Theses, and Capstone Projects

Mycobacterium tuberculosis (Mtb) is the pathogenic bacterium causative of tuberculosis. According to the 2021 World Health Organization (WHO) Global Tuberculosis (TB) Report, there were approximately 5.8 million TB cases in 2020, and 1.3 million TB deaths among HIV negative people in that year. The rise of multi-drug resistant Mtb strains has increased the need for more potent microbials against this pathogen. Biosynthesis of iron scavenging molecules, known as siderophores (e.g., mycobactin and carboxymycobactin), has been identified as a potential drug target candidate since iron acquisition has been directly linked to the survival and virulence of Mtb. Salicyl-AMS (Sal-AMS) is …