Medical Microbiology Commons^™

Development Of Phage Cocktails To Treat E Coli Catheter-Associated Urinary Tract Infection And Associated Biofilms, Belkys C Sanchez, Emmaline R Heckmann, Sabrina I Green, Justin R Clark, Heidi B Kaplan, Robert F Ramig, Casey Hines-Munson, Felicia Skelton, Barbara W Trautner, Anthony W Maresso

Faculty, Staff and Students Publications

High rates of antimicrobial resistance and formation of biofilms makes treatment of Escherichia coli catheter-associated urinary tract infections (CAUTI) particularly challenging. CAUTI affect 1 million patients per year in the United States and are associated with morbidity and mortality, particularly as an etiology for sepsis. Phage have been proposed as a potential therapeutic option. Here, we report the development of phage cocktails that lyse contemporary E. coli strains isolated from the urine of patients with spinal cord injury (SCI) and display strong biofilm-forming properties. We characterized E. coli phage against biofilms in two in vitro CAUTI models. Biofilm viability was …

Nuclear Progesterone Receptor Expressed By The Cortical Thymic Epithelial Cells Dictates Thymus Involution In Murine Pregnancy, Soo Hyun Ahn, Sean L Nguyen, Tae Hoon Kim, Jae-Wook Jeong, Ripla Arora, John P Lydon, Margaret G Petroff

Faculty, Staff and Students Publications

Progesterone is a gonadal pro-gestational hormone that is absolutely necessary for the success of pregnancy. Most notable actions of progesterone are observed in the female reproductive organs, the uterus and the ovary. Acting through the nuclear progesterone receptor (PGR), progesterone prepares the endometrium for implantation of the embryo. Interestingly, the maternal thymus also is a known expressor of Pgr; its absence is associated with murine pregnancy complications. However, the localization of its expression and its functional importance were not known. Here, we used a transgenic dual fluorescent reporter mouse model and genetic deletion of Pgr in Foxn1+ thymic epithelial …

Gut Microbiota From Sjögren Syndrome Patients Causes Decreased T Regulatory Cells In The Lymphoid Organs And Desiccation-Induced Corneal Barrier Disruption In Mice, Laura Schaefer, Claudia M Trujillo-Vargas, Firas S Midani, Stephen C Pflugfelder, Robert A Britton, Cintia S De Paiva

Faculty, Staff and Students Publications

Sjögren syndrome (SS) is an autoimmune inflammatory disorder characterized by secretory dysfunction in the eye and mouth; in the eye, this results in tear film instability, reduced tear production, and corneal barrier disruption. A growing number of studies show that homeostasis of the ocular surface is impacted by the intestinal microbiome, and several 16S sequencing studies have demonstrated dysbiosis of the intestinal microbiota in SS patients. In this study, we utilized metagenomic sequencing to perform a deeper analysis of the intestinal microbiome using stools collected from sex- and age-matched healthy (n = 20), dry eye (n = 4) …

Clonal Hematopoiesis Analyses In Clinical, Epidemiologic, And Genetic Aging Studies To Unravel Underlying Mechanisms Of Age-Related Dysfunction In Humans, Kenneth Walsh, Nalini Raghavachari, Candace Kerr, Alexander G Bick, Steven R Cummings, Todd Druley, Cynthia E Dunbar, Giulio Genovese, Margaret A Goodell, Siddhartha Jaiswal, Jaroslaw Maciejewski, Pradeep Natarajan, Anastasia V Shindyapina, Alan R Shuldiner, Erik B Van Den Akker, Jan Vijg

Faculty, Staff and Students Publications

Aging is characterized by increased mortality, functional decline, and exponential increases in the incidence of diseases such as cancer, stroke, cardiovascular disease, neurological disease, respiratory disease, etc. Though the role of aging in these diseases is widely accepted and considered to be a common denominator, the underlying mechanisms are largely unknown. A significant age-related feature observed in many population cohorts is somatic mosaicism, the detectable accumulation of somatic mutations in multiple cell types and tissues, particularly those with high rates of cell turnover (e.g., skin, liver, and hematopoietic cells). Somatic mosaicism can lead to the development of cellular clones that …

Identification Of Serum Mirna Signature And Establishment Of A Nomogram For Risk Stratification In Patients With Pancreatic Ductal Adenocarcinoma, Raju Kandimalla, Tadanobu Shimura, Saurav Mallik, Fuminori Sonohara, Susan Tsai, Douglas B Evans, Song Cheol Kim, Hideo Baba, Yasuhiro Kodera, Daniel Von Hoff, Xi Chen, Ajay Goel

Faculty, Staff and Students Publications

OBJECTIVE: The aim of the study was to perform mRNA-miRNA regulatory network analyses to identify a miRNA panel for molecular subtype identification and stratification of high-risk patients with pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND: Recent transcriptional profiling effort in PDAC has led to the identification of molecular subtypes that associate with poor survival; however, their clinical significance for risk stratification in patients with PDAC has been challenging.

METHODS: By performing a systematic analysis in The Cancer Genome Atlas and International Cancer Genome Consortium cohorts, we discovered a panel of miRNAs that associated with squamous and other poor molecular subtypes in PDAC. …

Modeling Nonsegmented Negative-Strand Rna Virus (Nnsv) Transcription With Ejective Polymerase Collisions And Biased Diffusion, Felipe-Andrés Piedra, David Henke, Anubama Rajan, Donna M Muzny, Harsha Doddapaneni, Vipin K Menon, Kristi L Hoffman, Matthew C Ross, Sara J Javornik Cregeen, Ginger Metcalf, Richard A Gibbs, Joseph F Petrosino, Vasanthi Avadhanula, Pedro A Piedra

Faculty, Staff and Students Publications

Infections by non-segmented negative-strand RNA viruses (NNSV) are widely thought to entail gradient gene expression from the well-established existence of a single promoter at the 3' end of the viral genome and the assumption of constant transcriptional attenuation between genes. But multiple recent studies show viral mRNA levels in infections by respiratory syncytial virus (RSV), a major human pathogen and member of NNSV, that are inconsistent with a simple gradient. Here we integrate known and newly predicted phenomena into a biophysically reasonable model of NNSV transcription. Our model succeeds in capturing published observations of respiratory syncytial virus and vesicular stomatitis …

Whole Lung Lavage: Treating Pulmonary Alveolar Proteinosis At The Time Of Covid Pandemic, Katherine Jean Powers, Vasanthi Avadhanula, Purvesh R Patel, Pralay Kumar Sarkar, Pedro Piedra, Neda Zarrin-Khameh

Faculty, Staff and Students Publications

Pulmonary alveolar proteinosis (PAP) is a rare syndrome due to increased production or decreased clearance of surfactant in alveoli and terminal bronchi that cause hypoxemic respiratory insufficiency. Here we present a patient with PAP whose disease was exacerbated by superimposed COVID-19 pneumonia. He underwent whole lung lavage (WLL). Evaluation of the viral count of the first and the last lavage of the left lung showed viral load in the alveolar space dropped by approximately 10-folds, however the magnitude of the viral load was substantial in both lavage samples. Whole pulmonary lavage may be used as a treatment option on patients …

Development Of Phage Cocktails To Treate Coli Catheter-Associated Urinary Tract Infection And Associated Biofilms, Belkys C Sanchez, Emmaline R Heckmann, Sabrina I Green, Justin R Clark, Heidi B Kaplan, Robert F Ramig, Casey Hines-Munson, Felicia Skelton, Barbara W Trautner, Anthony W Maresso

Faculty, Staff and Students Publications

High rates of antimicrobial resistance and formation of biofilms makes treatment of Escherichia coli catheter-associated urinary tract infections (CAUTI) particularly challenging. CAUTI affect 1 million patients per year in the United States and are associated with morbidity and mortality, particularly as an etiology for sepsis. Phage have been proposed as a potential therapeutic option. Here, we report the development of phage cocktails that lyse contemporary E. coli strains isolated from the urine of patients with spinal cord injury (SCI) and display strong biofilm-forming properties. We characterized E. coli phage against biofilms in two in vitro CAUTI models. Biofilm viability was …

Rotavirus-Induced Lipid Droplet Biogenesis Is Critical For Virus Replication, Jeanette M Criglar, Mary K Estes, Sue E Crawford

Faculty, Staff and Students Publications

A variety of pathogens, including viruses, bacteria and parasites, target cellular lipid droplets for their replication. Rotaviruses (RVs) infect the villous epithelium of the small intestine and are a major cause of acute gastroenteritis in infants and young children worldwide. RVs induce and require lipid droplets for the formation of viroplasms, sites of virus genome replication, and nascent particle assembly. Here we review the role of lipid droplets in RV replication. Inhibitors of fatty acid synthesis or chemicals that interfere with lipid droplet homeostasis decrease the number and size of viroplasms and the yield of infectious virus. We used a …

Modified Vaccinia Ankara Expressing Eehv1a Glycoprotein B Elicits Humoral And Cell-Mediated Immune Responses In Mice, Taylor Pursell, Jennifer L Spencer Clinton, Jie Tan, Rongsheng Peng, Paul D Ling

Faculty, Staff and Students Publications

Elephant endotheliotropic herpesvirus (EEHV) can cause lethal hemorrhagic disease (EEHV-HD) in Asian elephants and is the largest cause of death in captive juvenile Asian elephants in North America and Europe. EEHV-HD also has been documented in captive and wild elephants in their natural range countries. A safe and effective vaccine to prevent lethal EEHV infection would significantly improve conservation efforts for this endangered species. Recent studies from our laboratory suggest that EEHV morbidity and mortality are often associated with primary infection. Therefore, we aim to generate a vaccine, particularly for EEHV1 naïve animals, with the goal of preventing lethal EEHV-HD. …

Hypermethylation Of Pi3k-Akt Signalling Pathway Genes Is Associated With Human Neural Tube Defects, Tian Tian, Xinyuan Lai, Kuanhui Xiang, Xiao Han, Shengju Yin, Robert M Cabrera, John W Steele, Yunping Lei, Xuanye Cao, Richard H Finnell, Linlin Wang, Aiguo Ren

Faculty, Staff and Students Publications

Neural tube defects (NTDs) are a group of common and severe congenital malformations. The PI3K-AKT signalling pathway plays a crucial role in the neural tube development. There is limited evidence concerning any possible association between aberrant methylation in PI3K-AKT signalling pathway genes and NTDs. Therefore, we aimed to investigate potential associations between aberrant methylation of PI3K-AKT pathway genes and NTDs. Methylation studies of PI3K-AKT pathway genes utilizing microarray genome-methylation data derived from neural tissues of ten NTD cases and eight non-malformed controls were performed. Targeted DNA methylation analysis was subsequently performed in an independent cohort of 73 NTD cases and …

Interleukin-1Β Secretion Induced By Mucosa-Associated Gut Commensal Bacteria Promotes Intestinal Barrier Repair, Wan-Jung H Wu, Myunghoo Kim, Lin-Chun Chang, Adrien Assie, Fatima B Saldana-Morales, Daniel F Zegarra-Ruiz, Kendra Norwood, Buck S Samuel, Gretchen E Diehl

Faculty, Staff and Students Publications

The gut microbiota is essential for maintenance and repair of the intestinal epithelial barrier. As shifts in both intestinal epithelial barrier function and microbiota composition are found in inflammatory bowel disease patients, it is critical to understand the role of distinct bacteria in regulating barrier repair. We identified a mouse commensal E. coli isolate, GDAR2-2, that protects mice from Citrobacter rodentium infection and dextran sulfate sodium-induced colitis. Colonization with GDAR2-2 in mice resulted in expansion of CX3CR1+ mononuclear phagocytes, including CX3CR1+ macrophages/dendritic cells and monocytes, along with IL-22-secreting type 3 innate lymphoid cells and improved epithelial barrier function. In vitro …

Synthetic Flavonoid Derivatives With Antiviral Activity Against Dengue And Chikungunya Viruses, Van Cao

Chulalongkorn University Theses and Dissertations (Chula ETD)

Dengue infection is one significant global health issue, as climate change exacerbated the spread of mosquito vectors. The Chikungunya virus is also a re-emerging arbovirus infection, which is transmitted by some similar vectors. Currently, no commercial antiviral drug is available to treat them. Previous reports suggested that several flavonoid derivatives inhibited mosquito-borne flaviviruses even at submicromolar levels, and one of them is a halogenated flavone derivative, 8-bromobaicalein, was a potential dengue and Zika replication inhibitor targeting flaviviral polymerase and also 3CLpro of SARS-CoV-2. This study characterized that 8-bromobaicalein inhibited chikungunya virus replication with EC50 of 0.49 ± 0.11 µM in …

The Effect Of Histone Methylation In Trained Innate Immunity Of Cord Blood Monocytes In Newborn Infants Of Chronic Hbv-Infected Mothers, Pennapa Plypongsa

Chulalongkorn University Theses and Dissertations (Chula ETD)

Newborns contract Hepatitis B virus (HBV) through exposure in utero from mothers who are infected with HBV. In newborn infant from chronic HBV-infected mothers, the immune system displays innate immune cell maturation and enhances immune response upon restimulation with unrelated pathogens such as bacteria. This pattern is called “trained immunity” or “innate immune memory”. Trained immunity is regulated by epigenetic programming, especially histone modification. To date, there is not report on the epigenetics to regulate trained immunity in HBV. Therefore, this study investigated the cytokines levels and expression levels of histone modification enzyme genes in HBV-exposed cord blood monocytes. Moreover, …

Study Of Thermodynamic Binding Between Ader And Ades In Two-Component Antibiotic Sensor Of Antibiotic Resistant Strains Of Acinetobacter Baumannii, Konrawee Thananon

Chulalongkorn University Theses and Dissertations (Chula ETD)

The proteins AdeR (response regulator) and AdeS (histidine kinase sensor) play a crucial role in regulating the efflux pump, which is responsible for removing antibiotics from bacterial cells. This regulation occurs through a two-component regulatory system (TCS) involving autophosphorylation. Upon receiving external signals, AdeS undergoes autophosphorylation, leading to the activation of AdeR, which in turn initiates the expression of target genes related to the efflux pump. In this study, both enzymes from the reference strain of Acinetobacter baumannii (ATCC19606) and antibiotic resistant strains (H1074 and G560) were cloned and expressed in E. coli. The enzymes were purified using an immobilized …

Effect Of Candida Glabrata Β-Glucans On Immunosuppressive Properties Of Dendritic Cells, Phawida Tummamunkong

Chulalongkorn University Theses and Dissertations (Chula ETD)

β-glucan is a polysaccharide and consists of the backbone of β-(1, 3)-glucan and/or β-(1, 6)-glucan structures. β-glucans are extracted from the cell wall of Candida sp, including Candida glabrata. Interestingly, the biological activity of Candida β-glucan has been represented as a stimulator in the mechanism of immune responses. Dendritic cells are powerful antigen-presenting cells that play a significant role in both innate and adaptive immunity. In the present study, we evaluated the effect of C. glabrata β-glucans on dendritic cell (DC) immunologic responses. Firstly, bone marrow-derived DCs (BMDCs) were induced with C. glabrata β-glucans in a dose-dependent manner. The expression …

Generation Of Tolerogenic Dendritic Cells From Fcgr2b Deficient Lupus-Prone Mice For The Model Of Sle Therapy, Phuriwat Khiewkamrop

Chulalongkorn University Theses and Dissertations (Chula ETD)

Tolerogenic dendritic cells (tolDCs) are DCs with an immunoregulatory function, which can induce regulatory T cells (Tregs) and suppress the immune response. Currently, tolDCs-based treatment has become a promising therapeutic approach for organ transplantation and autoimmune disease. FcgRIIB is an inhibitory receptor widely expressed in B cells, myeloid cells, and DCs. The ablation of FcgRIIB in the murine model shows a spontaneous development of a lupus-like disease and might affect other immune cell regulation. There was limited information on tolDC induction in FcgRIIB defective mice. Thus, in this study, we studied the generation of tolDCs from the bone marrow-derived dendritic …

Macrophage Depletion Enhances Gut Dysbiosis And Severity In Sepsis Mouse Model, Pratsanee Hiengrach

Chulalongkorn University Theses and Dissertations (Chula ETD)

Macrophage is vital players in the responsiveness of the innate immune system against injury or infection. Although macrophage depletion is well-known for some emerging therapies, such as osteoporosis, osteopenia, and decreasing tumor-associated macrophages in melanoma, dysfunction of macrophages leads to an inability of an appropriate immune response and implicated in various disease processes, especially intestinal macrophages that play a key role in the gut immune system and the regulation of gastrointestinal physiology. To obtain an understanding of the role of sepsis-associated macrophages, clodronate was used for the dysfunction of mouse macrophages with and without cecal ligation and puncture (CLP) sepsis. …

The Inhibitory Effect Of Combined Human Cathelicidin With Antibiotics On Antibiotic-Resistant Cutibacterium Acnes, Rakwaree Sriharat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cutibacterium acnes is one of the major factors involved in the pathogenesis of acne vulgaris which sometimes develops antibiotic resistance particularly clindamycin- and doxycycline-resistant C. acnes. In this study, human cathelicidin (LL-37) which is a type of human antimicrobial peptide against a wide range of microorganisms was used. We investigated the antimicrobial activity of LL-37 on C. acnes isolated from patients with acne at the King Chulalongkorn Hospital using broth microdilution. Moreover, the synergistic effects of LL-37 with clindamycin and doxycycline were investigated using checkerboard microdilution, and time-killing assays. The cytotoxicity of LL-37 was also evaluated by MTT assay. The …

Epigenetic Regulation In Trained And Tolerized Macrophages, Salisa Benjaskulluecha

Chulalongkorn University Theses and Dissertations (Chula ETD)

Innate immune memory is the phenomenon that can either enhance (trained) or suppress (tolerized) immune response by innate immune cells during the second encounter of the stimuli such as pathogens. Previous studies reported that epigenetic regulations critically regulate both types of innate immune memory. However, a complete understanding of the underlying mechanisms is still lacking. In this study, we performed a screening of an epigenetics compound library to identify inhibitors that affect ß-glucan (BG)-trained or LPS-tolerized macrophages. Among 181 compounds tested, various inhibitors targeting Aurora kinase, histone methyltransferase PRMT and EZH2, histone demethylase LSD1 and JMJD2, histone deacetylase 6 and …

Decoding The Mystery Of Antibiotic Persistence, Tahmina Hossain

Electronic Theses and Dissertations

This work combines microbiology, molecular biology, Next-Generation Sequencing and system biology approaches to explore the mechanism of antibiotic persistence: a multi-drug tolerant, non-dividing, and metabolically altered state present in a subpopulation of cells due to phenotypic diversity rather than genetic variation (i.e. mutations). Persister can survive lethal antibiotic state and resuscitate after the treatment period is over. They are considered as the major contributing factor behind recurring infections. They also have a high mutation rate, which increases the chances of bacteria gaining antibiotic resistance. The formation of this phenotypic variant (persister) threatens the therapeutic effectiveness of antibiotics and understanding how …

Incfv Plasmid Ped208: Sequence Analysis And Evidence For Translocation Of Maintenance/Leading Region Proteins Through Diverse Type Iv Secretion Systems, Abu Amar M Al Mamun, Kimberly Kissoon, Kouhei Kishida, William C Shropshire, Blake Hanson, Peter J Christie

Faculty, Staff and Student Publications

Two phylogenetically distantly-related IncF plasmids, F and pED208, serve as important models for mechanistic and structural studies of F-like type IV secretion systems (T4SSFs) and F pili. Here, we present the pED208 sequence and compare it to F and pUMNF18, the closest match to pED208 in the NCBI database. As expected, gene content of the three cargo regions varies extensively, although the maintenance/leading regions (MLRs) and transfer (Tra) regions also carry novel genes or motifs with predicted modulatory effects on plasmid stability, dissemination and host range. By use of a Cre recombinase assay for translocation (CRAfT), we recently reported that …

Examining The Pulmonary Response To Repeated Vishniacozyma Victoriae Exposure And Its Association With Allergic Airway Disease, Rachael Erin Rush

Graduate Theses, Dissertations, and Problem Reports (ETD)

Allergic airway diseases such as asthma continue to increase in incidence in industrialized nations like the United States. These diseases are complex inflammatory processes involving numerous cells and mediators and are strongly influenced by fungal exposures. Recent developments in fungal detection methods have highlighted the contribution of Basidiomycota yeast species in indoor environments such as Vishniacozyma (syn. Cryptococcus) victoriae. However, despite the high levels of this yeast detected in indoor environments, very little is known about it or its role in respiratory morbidity. V. victoriae is phylogenetically similar to pathogenic Cryptococcus neoformans but lacks a capsule and is …

Microbial Contamination And Metabolite Exposure Assessment During Waste And Recyclable Material Collection, Fabiola Salambaga, Loïc Wingert, Isabelle Valois, Nancy Lacombe, François Gouin, Julien Trépanier, Maximilien Debia, Ewelina Soszczyńska, Magdalena Twarużek, Robert Kosicki, Marta Dias, Susana Viegas, Liliana Caetano, Carla Viegas, Geneviève Marchand

Études primaires

Waste workers are exposed to bioaerosols when handling, lifting and dumping garbage. Bioaerosol exposure has been linked to health problems such as asthma, airway irritant symptoms, infectious, gastrointestinal and skin diseases, and cancer. Our objective was to characterize the exposure of urban collectors and drivers to inhalable bioaerosols and to measured the cytotoxic effect of air samples in order to evaluate their health risk.

Personal and ambient air sampling were conducted during the summer of 2019. Workers from 12 waste trucks collecting recyclables, organic waste or compost were evaluated. Bacteria and fungi were cultured, molecular biology methods were used to …

An Investigation Into The Prevalence Of Vancomycin-Resistant Enterococci Within An Irish Hospital, Dylan Casey

International Undergraduate Journal of Health Sciences

Vancomycin-resistant enterococci (VRE) are well-recognised nosocomial pathogens that pose a significant threat to public health. Associated with poorer clinical outcomes than their vancomycin-sensitive counterparts, the prevalence of VRE in Ireland has increased in recent times, with the European Antimicrobial Resistance Surveillance Network reporting that out of 29 countries, Ireland demonstrated the highest rates of vancomycin resistance among invasive Enterococcus faecium isolates between 2011 and 2014 (2011; 34.9%, 2012; 44.0%, 2013; 42.7%, 2014; 45.1%). Herein, we investigate VRE prevalence in the Mercy University Hospital (MUH) – an acute care hospital in southern Ireland. A total of 21 first-time VRE infections were …

Eliminating Contamination In Umbilical Cord Blood Culture Sampling For Early-Onset Neonatal Sepsis., Vilmaris Quinones Cardona, Vanessa Lowery, David Cooperberg, Endla K Anday, Alison J Carey

Department of Pediatrics Faculty Papers

Introduction: Despite the advantages of umbilical cord blood culture (UCBC) use for diagnosis of early onset sepsis (EOS), contamination rates have deterred neonatologists from its widespread use. We aimed to implement UCBC collection in a level III neonatal intensive care unit (NICU) and apply quality improvement (QI) methods to reduce contamination in the diagnosis of early onset sepsis. Methods: Single-center implementation study utilizing quality improvement methodology to achieve 0% contamination rate in UCBC samples using the Plan-Do-Study-Act (PDSA) model for improvement. UCBC was obtained in conjunction with peripheral blood cultures (PBC) in neonates admitted to the NICU due to maternal …

The Mrna-Lnp Platform's Lipid Nanoparticle Component Used In Preclinical Vaccine Studies Is Highly Inflammatory, Sonia Ndeupen, Zhen Qin, Sonya Jacobsen, Aurélie Bouteau, Henri Estanbouli, Botond Z. Igyártó

Department of Microbiology and Immunology Faculty Papers

Vaccines based on mRNA-containing lipid nanoparticles (LNPs) are a promising new platform used by two leading vaccines against COVID-19. Clinical trials and ongoing vaccinations present with varying degrees of protection levels and side effects. However, the drivers of the reported side effects remain poorly defined. Here we present evidence that Acuitas' LNPs used in preclinical nucleoside-modified mRNA vaccine studies are highly inflammatory in mice. Intradermal and intramuscular injection of these LNPs led to rapid and robust inflammatory responses, characterized by massive neutrophil infiltration, activation of diverse inflammatory pathways, and production of various inflammatory cytokines and chemokines. The same dose of …

Evaluation Of Stratified Antibiograms For Use In Laboratory And Antimicrobial Stewardship, Linsey Donner

Theses & Dissertations

Antibiograms are critical for choosing empiric antimicrobial therapy. Cumulative antibiograms, which aggregate susceptibility data, can mask differences within specific patient subsets or clinical syndromes. This dissertation was done to determine if antibiotic susceptibilities showed substantial differences when comparing stratified antibiograms to cumulative antibiograms.

Antibiotic susceptibility data was retrospectively obtained from Nebraska Medicine January 1, 2017 – December 31, 2019 for Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis. The University of Nebraska Medical Center’s web antibiogram clinical decision support tool was used to export the data. Bacteria-antibiotic susceptibility rates of stratified antibiograms …

Characterizing And Overcoming Resistance To Aminomethylspectinomycins In Gram-Negative Bacteria, Nisha Das

Theses and Dissertations (ETD)

Spectinomycin (SPC) is a broad-spectrum aminocyclitol antibiotic. Its use in agriculture has led to widespread resistance in enteric bacteria, necessitating the development of more effective analogs. Aminomethyl spectinomycins (amSPC) are modified spectinomycins with increased potency against many bacterial species. These species include Legionella pneumophila, which harbors a chromosomally encoded aminoglycoside modifying enzyme (AME). In this study, we follow up on this observation and examine the extent to which the amSPCs are substrates for AMEs through adenylation (ANTs) and phosphorylation (APH). APH(9)-Ia and ANT(3")(9) were expressed in E. coli BL21(DE3) and purified using the Ni-affinity chromatography. The ability of AMEs to …

Sars-Cov-2 Induces Robust Germinal Center Cd4 T Follicular Helper Cell Responses In Rhesus Macaques, Yashavanth Shaan Lakshmanappa, Sonny R. Elizaldi, Jamin W. Roh, Brian A. Schmidt, Timothy D. Carroll, Kourtney D. Weaver, Justin C. Smith, Anil Verma, Jesse D. Deere, Joseph Dutra, Mars Stone, Sergej Franz, Rebecca Lee Sammak, Katherine J. Olstad, J. Rachel Reader, Zhong Min Ma, Nancy K. Nguyen, Jennifer Watanabe, Jodie Usachenko, Ramya Immareddy

School of Graduate Studies Faculty Publications

CD4 T follicular helper (Tfh) cells are important for the generation of durable and specific humoral protection against viral infections. The degree to which SARS-CoV-2 infection generates Tfh cells and stimulates the germinal center (GC) response is an important question as we investigate vaccine induced immunity against COVID-19. Here, we report that SARS-CoV-2 infection in rhesus macaques, either infused with convalescent plasma, normal plasma, or receiving no infusion, resulted in transient accumulation of pro-inflammatory monocytes and proliferating Tfh cells with a Th1 profile in peripheral blood. CD4 helper cell responses skewed predominantly toward a Th1 response in blood, lung, and …