Medical Microbiology Commons^™

Topical Anesthetic Gel Interferes With Antibacterial Efficacy Of Povidone-Iodine Both In Vitro And In Vivo, Cecilly Kelleher Bs, Jacob Im Md, Linda Kang Bs, Aleksey Mishulin Md, Sukhvinder Singh Phd, Ashok Kumar Phd

Medical Student Research Symposium

Purpose: To evaluate the effects of viscous lidocaine gel on the antimicrobial efficacy of povidone-iodine (PI) and their order of application in both in vitro and in vivo models.

Methods: In vitro antibacterial effects were tested against Staphylococcus aureus (S. aureus) with disc diffusion methods for application of lidocaine alone, PI alone, PI before lidocaine, and lidocaine before PI. Zones of inhibition were measured after incubation at 37°C overnight. Mouse eyes were colonized with S. aureus for in vivo study to which PI and/or lidocaine were applied in various combinations. Eyes were then rinsed with saline, and …

Differential Spatial Gene And Protein Expression Associated With Recurrence Following Chemoradiation For Localized Anal Squamous Cell Cancer, Sharia Hernandez, Prajnan Das, Emma B Holliday, Li Shen, Wei Lu, Benny Johnson, Craig A Messick, Cullen M Taniguchi, John Skibber, Ethan B Ludmir, Y Nancy You, Grace Li Smith, Brian Bednarski, Larisa Kostousov, Eugene J Koay, Bruce D Minsky, Matthew Tillman, Shaelynn Portier, Cathy Eng, Albert C Koong, George J Chang, Wai Chin Foo, Jing Wang, Luisa Solis Soto, Van K Morris

Faculty, Staff and Student Publications

The identification of transcriptomic and protein biomarkers prognosticating recurrence risk after chemoradiation of localized squamous cell carcinoma of the anus (SCCA) has been limited by a lack of available fresh tissue at initial presentation. We analyzed archival FFPE SCCA specimens from pretreatment biopsies prior to chemoradiation for protein and RNA biomarkers from patients with localized SCCA who recurred (N = 23) and who did not recur (N = 25). Tumor cells and the tumor microenvironment (TME) were analyzed separately to identify biomarkers with significantly different expression between the recurrent and non-recurrent groups. Recurrent patients had higher mean protein expression of …

Structure-Based Regulatory Role For The 5'Utr Of Rcnmv Rna2, Jennifer S H Im, Jasmine R Sheppard, K Andrew White

Faculty, Staff and Student Publications

Red clover necrotic mosaic virus (RCNMV) is a segmented positive-strand RNA virus consisting of RNA1 and RNA2. Previous studies demonstrated that efficient translation of RCNMV RNA2 requires de novo synthesis of RNA2 during infections, suggesting that RNA2 replication is required for its translation. We explored a potential mechanism underlying the regulation of replication-associated translation of RNA2 by examining RNA elements in its 5' untranslated region (5'UTR). Structural analysis of the 5'UTR suggested that it can form two mutually exclusive configurations: a more thermodynamically stable conformation, termed the 5'-basal stem structure (5'BS), in which 5'-terminal sequences are base paired, and an …

Microbiome Influencers Of Checkpoint Blockade-Associated Toxicity, Yinghong Wang, Robert R Jenq, Jennifer A Wargo, Stephanie S Watowich

Faculty, Staff and Student Publications

Immunotherapy has greatly improved cancer outcomes, yet variability in response and off-target tissue damage can occur with these treatments, including immune checkpoint inhibitors (ICIs). Multiple lines of evidence indicate the host microbiome influences ICI response and risk of immune-related adverse events (irAEs). As the microbiome is modifiable, these advances indicate the potential to manipulate microbiome components to increase ICI success. We discuss microbiome features associated with ICI response, with focus on bacterial taxa and potential immune mechanisms involved in irAEs, and the overall goal of driving novel approaches to manipulate the microbiome to improve ICI efficacy while avoiding irAE risk.

Pyroptosis In Neutrophils: Multimodal Integration Of Inflammasome And Regulated Cell Death Signaling Pathways, George R Dubyak, Brandon A Miller, Eric Pearlman

Faculty, Staff and Student Publications

Pyroptosis is a proinflammatory mode of lytic cell death mediated by accumulation of plasma membrane (PM) macropores composed of gasdermin-family (GSDM) proteins. It facilitates two major functions in innate immunity: (i) elimination of intracellular replicative niches for pathogenic bacteria; and (ii) non-classical secretion of IL-1 family cytokines that amplify host-beneficial inflammatory responses to microbial infection or tissue damage. Physiological roles for gasdermin D (GSDMD) in pyroptosis and IL-1β release during inflammasome signaling have been extensively characterized in macrophages. This involves cleavage of GSDMD by caspase-1 to generate GSDMD macropores that mediate IL-1β efflux and progression to pyroptotic lysis. Neutrophils, which …

Bacterial Division Ring Stabilizing Zapa Versus Destabilizing Slma Modulate Ftsz Switching Between Biomolecular Condensates And Polymers, Begoña Monterroso, Miguel Ángel Robles-Ramos, Marta Sobrinos-Sanguino, Juan Román Luque-Ortega, Carlos Alfonso, William Margolin, Germán Rivas, Silvia Zorrilla

Faculty, Staff and Student Publications

Cytokinesis is a fundamental process for bacterial survival and proliferation, involving the formation of a ring by filaments of the GTPase FtsZ, spatio-temporally regulated through the coordinated action of several factors. The mechanisms of this regulation remain largely unsolved, but the inhibition of FtsZ polymerization by the nucleoid occlusion factor SlmA and filament stabilization by the widely conserved cross-linking protein ZapA are known to play key roles. It was recently described that FtsZ, SlmA and its target DNA sequences (SlmA-binding sequence (SBS)) form phase-separated biomolecular condensates, a type of structure associated with cellular compartmentalization and resistance to stress. Using biochemical …

Prevalence And Predictors Of Using Antibiotics Without A Prescription In A Pediatric Population In The United States, Kiara Olmeda, Barbara W Trautner, Lindsey Laytner, Juanita Salinas, Stephanie Marton, Larissa Grigoryan

Faculty, Staff and Students Publications

Non-prescription antibiotic use (using antibiotics without clinical guidance) increases the risk of the development of antibiotic resistance, adverse drug reactions, and other potential patient harm. Few studies have explored non-prescription use in children in the U.S. From January 2021 to April 2022, a diverse sample of caregivers of children under 18 years were surveyed in English and Spanish at two safety net clinics in Texas. We assessed the prevalence of antibiotic use in children in the previous 12 months, storage of antimicrobials, and intended use of non-prescription antibiotics (professed intention for future non-prescription antibiotic use). We also measured sociodemographic factors, …

The Tumor-Immune Ecosystem In Shaping Metastasis, Yang Gao, Jeffrey M Rosen, Xiang H-F Zhang

Faculty, Staff and Students Publications

A better understanding of the mechanisms regulating cancer metastasis is critical to develop new therapies and decrease mortality. Emerging evidence suggests that the interactions between tumor cells and the host immune system play important roles in establishing metastasis. Tumor cells are able to recruit immune cells, which in turn promotes tumor cell invasion, intravasation, survival in circulation, extravasation, and colonization in different organs. The tumor-host immunological interactions also generate a premetastatic niche in distant organs which facilitates metastasis. In this review, we summarize the recent findings on how tumor cells and immune cells regulate each other to coevolve and promote …

The Tfiis N-Terminal Domain (Tnd): A Transcription Assembly Module At The Interface Of Order And Disorder, Katerina Cermakova, Vaclav Veverka, H Courtney Hodges

Faculty, Staff and Students Publications

Interaction scaffolds that selectively recognize disordered protein strongly shape protein interactomes. An important scaffold of this type that contributes to transcription is the TFIIS N-terminal domain (TND). The TND is a five-helical bundle that has no known enzymatic activity, but instead selectively reads intrinsically disordered sequences of other proteins. Here, we review the structural and functional properties of TNDs and their cognate disordered ligands known as TND-interacting motifs (TIMs). TNDs or TIMs are found in prominent members of the transcription machinery, including TFIIS, super elongation complex, SWI/SNF, Mediator, IWS1, SPT6, PP1-PNUTS phosphatase, elongin, H3K36me3 readers, the transcription factor MYC, and …

Uncovering Novel Regulators Of Memory Using C Elegans Genetic And Genomic Analysis, Katie L Brandel-Ankrapp, Rachel N Arey

Faculty, Staff and Students Publications

How organisms learn and encode memory is an outstanding question in neuroscience research. Specifically, how memories are acquired and consolidated at the level of molecular and gene pathways remains unclear. In addition, memory is disrupted in a wide variety of neurological disorders; therefore, discovering molecular regulators of memory may reveal therapeutic targets for these disorders. C. elegans are an excellent model to uncover molecular and genetic regulators of memory. Indeed, the nematode's invariant neuronal lineage, fully mapped genome, and conserved associative behaviors have allowed the development of a breadth of genetic and genomic tools to examine learning and memory. In …

Identification Of Small-Molecule Inhibitors Of The Salmonella Frab Deglycase Using A Live-Cell Assay, Anice Sabag-Daigle, Erin F Boulanger, Pankajavalli Thirugnanasambantham, Jamison D Law, Alex J Bogard, Edward J Behrman, Venkat Gopalan, Brian M M Ahmer

Faculty, Staff and Student Publications

Nontyphoidal salmonellosis is one of the most significant foodborne diseases in the United States and globally. There are no vaccines available for human use to prevent this disease, and only broad-spectrum antibiotics are available to treat complicated cases of the disease. However, antibiotic resistance is on the rise and new therapeutics are needed. We previously identified the Salmonella fraB gene, that mutation of causes attenuation of fitness in the murine gastrointestinal tract. The FraB gene product is encoded in an operon responsible for the uptake and utilization of fructose-asparagine (F-Asn), an Amadori product found in several human foods. Mutations in …

Development Of Bacteriophage Therapy For Novel Treatment Of Bacterial Infections, Terry Ann Else, Guadalupe Mercado

Annual Research Symposium

No abstract provided.

Structural Basis Of Impaired Disaggregase Function In The Oxidation-Sensitive Skd3 Mutant Causing 3-Methylglutaconic Aciduria, Jose J Gorbea Colón, Leon Palao, Shin-Fu Chen, Hee Jong Kim, Laura Snyder, Yi-Wei Chang, Kuang-Lei Tsai, Kenji Murakami

Faculty, Staff and Student Publications

Most eukaryotic promoter regions are divergently transcribed. As the RNA polymerase II pre-initiation complex (PIC) is intrinsically asymmetric and responsible for transcription in a single direction, it is unknown how divergent transcription arises. Here, the Saccharomyces cerevisiae Mediator complexed with a PIC (Med-PIC) was assembled on a divergent promoter and analyzed by cryoelectron microscopy. The structure reveals two distinct Med-PICs forming a dimer through the Mediator tail module, induced by a homodimeric activator protein localized near the dimerization interface. The tail dimer is associated with ∼80-bp upstream DNA, such that two flanking core promoter regions are positioned and oriented in …

Intestinal Neuropod Cell Gucy2c Regulates Visceral Pain, Joshua R. Barton, Annie K. Londregran, Tyler D. Alexander, Ariana A. Entezari, Shely Bar-Ad, Lan Cheng, Angelo C. Lepore, Adam E. Snook, Manuel Covarrubias, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Visceral pain (VP) is a global problem with complex etiologies and limited therapeutic options. Guanylyl cyclase C (GUCY2C), an intestinal receptor producing cyclic GMP(cGMP), which regulates luminal fluid secretion, has emerged as a therapeutic target for VP. Indeed, FDA-approved GUCY2C agonists ameliorate VP in patients with chronic constipation syndromes, although analgesic mechanisms remain obscure. Here, we revealed that intestinal GUCY2C was selectively enriched in neuropod cells, a type of enteroendocrine cell that synapses with submucosal neurons in mice and humans. GUCY2Chi neuropod cells associated with cocultured dorsal root ganglia neurons and induced hyperexcitability, reducing the rheobase and increasing the resulting …

Staphylococcus Aureus Breast Implant Infection Isolates Display Recalcitrance To Antibiotic Pocket Irrigants, Jesus M Duran Ramirez, Jana Gomez, Blake M Hanson, Taha Isa, Terence M Myckatyn, Jennifer N Walker

Faculty, Staff and Student Publications

Breast implant-associated infections (BIAIs) are the primary complication following placement of breast prostheses in breast cancer reconstruction. Given the prevalence of breast cancer, reconstructive failure due to infection results in significant patient distress and health care expenditures. Thus, effective BIAI prevention strategies are urgently needed. This study tests the efficacy of one infection prevention strategy: the use of a triple antibiotic pocket irrigant (TAPI) against Staphylococcus aureus, the most common cause of BIAIs. TAPI, which consists of 50,000 U bacitracin, 1 g cefazolin, and 80 mg gentamicin diluted in 500 mL of saline, is used to irrigate the breast implant …

Cell-Membrane-Coated Nanoparticles For Targeted Drug Delivery To The Brain For The Treatment Of Neurological Diseases, Jianzhuang Li, Yanhao Wei, Chunlin Zhang, Rentang Bi, Yanmei Qiu, Yanan Li, Bo Hu

Faculty, Staff and Student Publications

Neurological diseases (NDs) are a significant cause of disability and death in the global population. However, effective treatments still need to be improved for most NDs. In recent years, cell-membrane-coated nanoparticles (CMCNPs) as drug-targeting delivery systems have become a research hotspot. Such a membrane-derived, nano drug-delivery system not only contributes to avoiding immune clearance but also endows nanoparticles (NPs) with various cellular and functional mimicries. This review article first provides an overview of the function and mechanism of single/hybrid cell-membrane-derived NPs. Then, we highlight the application and safety of CMCNPs in NDs. Finally, we discuss the challenges and opportunities in …

Visualization Of Preimplantation Uterine Fluid Absorption In Mice Using Alexa Fluor™ 488 Hydrazide†, Yuehuan Li, Taylor Elijah Martin, Jonathan Matthew Hancock, Rong Li, Suvitha Viswanathan, John P Lydon, Yi Zheng, Xiaoqin Ye

Faculty, Staff and Students Publications

Uterine fluid plays important roles in supporting early pregnancy events and its timely absorption is critical for embryo implantation. In mice, its volume is maximum on day 0.5 post-coitum (D0.5) and approaches minimum upon embryo attachment ~D4.0. Its secretion and absorption in ovariectomized rodents were shown to be promoted by estrogen and progesterone (P4), respectively. The temporal mechanisms in preimplantation uterine fluid absorption remain to be elucidated. We have established an approach using intraluminally injected Alexa Fluor™ 488 Hydrazide (AH) in preimplantation control (RhoAf/f) and P4-deficient RhoAf/fPgrCre/+ mice. In control mice, bulk entry (seen as smeared cellular staining) via uterine …

In Vivo Gene Delivery Into Mouse Mammary Epithelial Cells Through Mammary Intraductal Injection, Wen Bu, Yi Li

Faculty, Staff and Students Publications

Mouse mammary glands comprise ductal trees, which are lined by epithelial cells and have one opening at the tip of each nipple. The epithelial cells play a major role in mammary gland function and are the origin of most mammary tumors. Introducing genes of interest into mouse mammary epithelial cells is a critical step in evaluating gene function in epithelial cells and generating mouse mammary tumor models. This goal can be accomplished through the intraductal injection of a viral vector carrying the genes of interest into the mouse mammary ductal tree. The injected virus subsequently infects mammary epithelial cells, bringing …

Effects Of Adjuvants In A Rabies-Vectored Ebola Virus Vaccine On Protection From Surrogate Challenge, Catherine Yankowski, Drishya Kurup, Christoph Wirblich, Matthias J. Schnell

Department of Microbiology and Immunology Faculty Papers

Ebola virus is the primary contributor to the global threat of filovirus severe hemorrhagic fever, and Ebola virus disease has a case fatality rate of 50-90%. An inactivated, bivalent filovirus/rabies virus vaccine, FILORAB1, consists of recombinant rabies virus virions expressing the Ebola virus glycoprotein. FILORAB1 is immunogenic and protective from Ebola virus challenge in mice and non-human primates, and protection is enhanced when formulated with toll-like receptor 4 agonist Glucopyranosyl lipid adjuvant (GLA) in a squalene oil-in-water emulsion (SE). Through an adjuvant comparison in mice, we demonstrate that GLA-SE improves FILORAB1 efficacy by activating the innate immune system and shaping …

Severe Acute Respiratory Syndrome Coronavirus 2 (Sars-Cov-2) Testing And Detection During Peripartum Hospitalizations Among A Multicenter Cohort Of Pregnant Persons: March 2020-February 2021, Miranda J Delahoy, Flor Munoz, De-Kun Li, Carmen Sofia Arriola, Nanette Lee Bond, Michael Daugherty, Jeannette Ferber, Nickolas Ferguson, Louise Hadden, Jillian T Henderson, Stephanie A Irving, Mary Juergens, Venkatesh Kancharla, Mara Greenberg, Roxana Odouli, Gabriella Newes-Adeyi, Erin G Nicholson, Lawrence Reichle, Momodou Sanyang, Margaret Snead, Fatimah S Dawood, Allison L Naleway

Faculty, Staff and Students Publications

BACKGROUND: Identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections during peripartum hospitalizations is important to guide care, implement prevention measures, and understand infection burden.

METHODS: This cross-sectional analysis used electronic health record data from hospitalizations during which pregnancies ended (peripartum hospitalizations) among a cohort of pregnant persons at 3 US integrated healthcare networks (sites 1-3). Maternal demographic, medical encounter, SARS-CoV-2 testing, and pregnancy and neonatal outcome information was extracted for persons with estimated delivery and pregnancy end dates during March 2020-February 2021 and ≥1 antenatal care record. Site-stratified multivariable logistic regression was used to identify factors associated with testing …