Medical Microbiology Commons^™

Myths And Methodologies: Cardiopulmonary Exercise Testing For Surgical Risk Stratification In Patients With An Abdominal Aortic Aneurysm; Balancing Risk Over Benefit, Damian M Bailey, Richard G Davies, George A Rose, Michael H Lewis, Ahmed Abd Aldayem, Chistopher P Twine, Wael Awad, Matti Jubouri, Idhrees Mohammed, Carlos A Mestres, Edward P Chen, Joseph S Coselli, Ian M Williams, Mohamad Bashir, International Academic Surgical Consortium (Thalamus)

Faculty, Staff and Students Publications

The extent to which patients with an abdominal aortic aneurysm (AAA) should exercise remains unclear, given theoretical concerns over the perceived risk of blood pressure-induced rupture, which is often catastrophic. This is especially pertinent during cardiopulmonary exercise testing, when patients are required to perform incremental exercise to symptom-limited exhaustion for the determination of cardiorespiratory fitness. This multimodal metric is being used increasingly as a complementary diagnostic tool to inform risk stratification and subsequent management of patients undergoing AAA surgery. In this review, we bring together a multidisciplinary group of physiologists, exercise scientists, anaesthetists, radiologists and surgeons to challenge the enduring …

Maternal Metabolism Influences Neural Tube Closure, Rachel A Keuls, Richard H Finnell, Ronald J Parchem

Faculty, Staff and Students Publications

Changes in maternal nutrient availability due to diet or disease significantly increase the risk of neural tube defects (NTDs). Because the incidence of metabolic disease continues to rise, it is urgent that we better understand how altered maternal nutrient levels can influence embryonic neural tube development. Furthermore, primary neurulation occurs before placental function during a period of histiotrophic nutrient exchange. In this review we detail how maternal metabolites are transported by the yolk sac to the developing embryo. We discuss recent advances in understanding how altered maternal levels of essential nutrients disrupt development of the neuroepithelium, and identify points of …

Igg3 Subclass Antibodies Recognize Antigenically Drifted Influenza Viruses And Sars-Cov-2 Variants Through Efficient Bivalent Binding, Marcus J. Bolton, Jefferson J.S. Santos, Claudia P. Arevalo, Trevor Griesman, Megan Watson, Shuk Hang Li, Paul Bates, Holly Ramage, Patrick C. Wilson, Scott E. Hensley

Department of Microbiology and Immunology Faculty Papers

The constant domains of antibodies are important for effector functions, but less is known about how they can affect binding and neutralization of viruses. Here, we evaluated a panel of human influenza virus monoclonal antibodies (mAbs) expressed as IgG1, IgG2, or IgG3. We found that many influenza virus-specific mAbs have altered binding and neutralization capacity depending on the IgG subclass encoded and that these differences result from unique bivalency capacities of the subclasses. Importantly, subclass differences in antibody binding and neutralization were greatest when the affinity for the target antigen was reduced through antigenic mismatch. We found that antibodies expressed …

A Non-Coding Insertional Mutation Of Grhl2 Causes Gene Over-Expression And Multiple Structural Anomalies Including Cleft Palate, Spina Bifida And Encephalocele, Zoe Crane-Smith, Sandra C P De Castro, Evanthia Nikolopoulou, Paul Wolujewicz, Damian Smedley, Yunping Lei, Emma Mather, Chloe Santos, Mark Hopkinson, Andrew A Pitsillides, Richard H Finnell, M Elisabeth Ross, Andrew J Copp, Nicholas D E Greene

Faculty, Staff and Students Publications

Orofacial clefts, including cleft lip and palate (CL/P) and neural tube defects (NTDs) are among the most common congenital anomalies, but knowledge of the genetic basis of these conditions remains incomplete. The extent to which genetic risk factors are shared between CL/P, NTDs and related anomalies is also unclear. While identification of causative genes has largely focused on coding and loss of function mutations, it is hypothesized that regulatory mutations account for a portion of the unidentified heritability. We found that excess expression of Grainyhead-like 2 (Grhl2) causes not only spinal NTDs in Axial defects (Axd) mice but also multiple …

Effect Of Various Types Of Extracellular Dna On V Hyugaensis Biofilm Formation, Carmen Gu Liu, Anthony W Maresso

Faculty, Staff and Students Publications

Marine bacteria face a constant influx of new extracellular DNA (exDNA) due to the massive viral lysis that occurs in the ocean on a daily basis. Generally, biofilms have shown to be induced by self-secreted exDNA. However, the effect of various types of exDNA with varying lengths, self vs non-self, as well as guanine-cytosine content (GC) content on biofilm formation has not been explored, despite being a critical component of the extracellular polymeric substance. To test the effect of such exDNA on biofilms, a marine bioluminescent bacterium (Vibrio hyugaensis) was isolated from the Sippewissett Salt Marsh, USA, and …

Multiomic Investigations Into Lung Health And Disease, Sarah E Blutt, Cristian Coarfa, Josef Neu, Mohan Pammi

Faculty, Staff and Students Publications

Diseases of the lung account for more than 5 million deaths worldwide and are a healthcare burden. Improving clinical outcomes, including mortality and quality of life, involves a holistic understanding of the disease, which can be provided by the integration of lung multi-omics data. An enhanced understanding of comprehensive multiomic datasets provides opportunities to leverage those datasets to inform the treatment and prevention of lung diseases by classifying severity, prognostication, and discovery of biomarkers. The main objective of this review is to summarize the use of multiomics investigations in lung disease, including multiomics integration and the use of machine learning …

Severe Covid-19 Following Rituximab And Nirmatrelvir/Ritonavir Treatment In A Patient With Mctd, Case Report, Rohail A. Baig, Faieja Chowdhury, Omar Siddiqui, Adnaan Sheikh, Varun Mehta, Pranjali Dakwale

Advances in Clinical Medical Research and Healthcare Delivery

This is an article about how the use of medications such as nirmatrelvir/ritonavir can cause rebound COVID-19 and how the use of Rituximab, a biologic agent, can prolong the duration and increase severity of symptoms of COVID-19 in patients with pre-disposed autoimmune diseases that are on chronic pharmacotherapy.

Phylogenetic Inference From Single-Cell Rna-Seq Data, Xuan Liu, Jason I Griffiths, Isaac Bishara, Jiayi Liu, Andrea H Bild, Jeffrey T Chang

Faculty, Staff and Student Publications

Tumors are comprised of subpopulations of cancer cells that harbor distinct genetic profiles and phenotypes that evolve over time and during treatment. By reconstructing the course of cancer evolution, we can understand the acquisition of the malignant properties that drive tumor progression. Unfortunately, recovering the evolutionary relationships of individual cancer cells linked to their phenotypes remains a difficult challenge. To address this need, we have developed PhylinSic, a method that reconstructs the phylogenetic relationships among cells linked to their gene expression profiles from single cell RNA-sequencing (scRNA-Seq) data. This method calls nucleotide bases using a probabilistic smoothing approach and then …

Loss Of Microrna-30a And Sex-Specific Effects On The Neonatal Hyperoxic Lung Injury, Sandra L Grimm, Samuel Reddick, Xiaoyu Dong, Connor Leek, Amy Xiao Wang, Manuel Cantu Gutierrez, Sean M Hartig, Bhagavatula Moorthy, Cristian Coarfa, Krithika Lingappan

Faculty, Staff and Students Publications

BACKGROUND: Bronchopulmonary dysplasia (BPD) is characterized by an arrest in lung development and is a leading cause of morbidity in premature neonates. It has been well documented that BPD disproportionally affects males compared to females, but the molecular mechanisms behind this sex-dependent bias remain unclear. Female mice show greater preservation of alveolarization and angiogenesis when exposed to hyperoxia, accompanied by increased miR-30a expression. In this investigation, we tested the hypothesis that loss of miR-30a would result in male and female mice experiencing similar impairments in alveolarization and angiogenesis under hyperoxic conditions.

METHODS: Wild-type and miR-30a−/− neonatal mice were exposed …

The At-Hook Is An Evolutionarily Conserved Auto-Regulatory Domain Of Swi/Snf Required For Cell Lineage Priming, Dhurjhoti Saha, Solomon Hailu, Arjan Hada, Junwoo Lee, Jie Luo, Jeff A Ranish, Yuan-Chi Lin, Kyle Feola, Jim Persinger, Abhinav Jain, Bin Liu, Yue Lu, Payel Sen, Blaine Bartholomew

Faculty, Staff and Student Publications

The SWI/SNF ATP-dependent chromatin remodeler is a master regulator of the epigenome, controlling pluripotency and differentiation. Towards the C-terminus of the catalytic subunit of SWI/SNF is a motif called the AT-hook that is evolutionary conserved. The AT-hook is present in many chromatin modifiers and generally thought to help anchor them to DNA. We observe however that the AT-hook regulates the intrinsic DNA-stimulated ATPase activity aside from promoting SWI/SNF recruitment to DNA or nucleosomes by increasing the reaction velocity a factor of 13 with no accompanying change in substrate affinity (K

Spatial Transcriptomics Of Intraductal Papillary Mucinous Neoplasms Of The Pancreas Identifies Nkx6-2 As A Driver Of Gastric Differentiation And Indolent Biological Potential, Marta Sans, Yuki Makino, Jimin Min, Kimal I Rajapakshe, Michele Yip-Schneider, C Max Schmidt, Mark W Hurd, Jared K Burks, Javier A Gomez, Fredrik I Thege, Johannes F Fahrmann, Robert A Wolff, Michael P Kim, Paola A Guerrero, Anirban Maitra

Faculty, Staff and Student Publications

Intraductal Papillary Mucinous Neoplasms (IPMNs) of the pancreas are bona fide precursor lesions of pancreatic ductal adenocarcinoma (PDAC). The most common subtype of IPMNs harbor a gastric foveolar-type epithelium, and these low-grade mucinous neoplasms are harbingers of IPMNs with high-grade dysplasia and cancer. The molecular underpinning of gastric differentiation in IPMNs is unknown, although identifying drivers of this indolent phenotype might enable opportunities for intercepting progression to high-grade IPMN and cancer. We conducted spatial transcriptomics on a cohort of IPMNs, followed by orthogonal and cross species validation studies, which established the transcription factor NKX6-2 as a key determinant of gastric …

Two Structurally Defined Aβ Polymorphs Promote Different Pathological Changes In Susceptible Mice, Ruben Gomez-Gutierrez, Ujjayini Ghosh, Wai-Ming Yau, Nazaret Gamez, Katherine Do, Carlos Kramm, Hamid Shirani, Laura Vegas-Gomez, Jonathan Schulz, Ines Moreno-Gonzalez, Antonia Gutierrez, K Peter R Nilsson, Robert Tycko, Claudio Soto, Rodrigo Morales

Faculty, Staff and Student Publications

Misfolded Aβ is involved in the progression of Alzheimer's disease (AD). However, the role of its polymorphic variants or conformational strains in AD pathogenesis is not fully understood. Here, we study the seeding properties of two structurally defined synthetic misfolded Aβ strains (termed 2F and 3F) using in vitro and in vivo assays. We show that 2F and 3F strains differ in their biochemical properties, including resistance to proteolysis, binding to strain-specific dyes, and in vitro seeding. Injection of these strains into a transgenic mouse model produces different pathological features, namely different rates of aggregation, formation of different plaque types, …

Alternative Splicing Of Ceacam1 By Hypoxia-Inducible Factor-1Α Enhances Tolerance To Hepatic Ischemia In Mice And Humans, Kenneth J Dery, Hidenobu Kojima, Shoichi Kageyama, Kentaro Kadono, Hirofumi Hirao, Brian Cheng, Yuan Zhai, Douglas G Farmer, Fady M Kaldas, Xiaoyi Yuan, Holger K Eltzschig, Jerzy W Kupiec-Weglinski

Faculty, Staff and Student Publications

Although alternative splicing (AS) drives transcriptional responses and cellular adaptation to environmental stresses, its contributions in organ transplantation have not been appreciated. We have shown that carcinoembryonic antigen-related cell adhesion molecule (Ceacam1; CD66a), a transmembrane biliary glycoprotein expressed in epithelial, endothelial, and immune cells, determines donor liver transplant quality. Here, we studied how AS of Ceacam1 affects ischemia-reperfusion injury (IRI) in mouse and human livers. We found that the short cytoplasmic isoform Ceacam1-S increased during early acute and late resolution phases of warm IRI injury in mice. Transfection of Ceacam1-deficient mouse hepatocytes with adenoviral Ceacam1-S mitigated hypoxia-induced loss of …

Impacts Of A Duf2207 Family Protein On Streptococcus Mutans Stress Tolerance Responses And Biofilm Formation, Xiaochang Huang, Camile G. Laird, Paul P. Riley, Zezhang Tom Wen

School of Dentistry Faculty Publications

Locus SMU.243 in Streptococcus mutans was annotated as a member of the DUF2207 family proteins highly conserved in all bacteria but with unknown function. To investigate its role in S. mutans physiology, a SMU.243-deficient mutant was constructed using allelic exchange mutagenesis, and the impacts of SMU.243 deletion on bacterial growth, stress tolerance response, and biofilm formation were analyzed. Compared to the wild-type UA159, S. mutans lacking SMU.243 displayed a reduced growth rate and a reduced overnight culture density (p < 0.01) when grown at low pH and in the presence of methyl viologen. Relative to the parent strain, the deficient mutant also had a reduced survival rate following incubation in a buffer of pH 2.8 (p < 0.01) and in a buffer containing hydrogen peroxide at 58 mM after 60 min (p < 0.001) and had a reduced capacity in biofilm formation especially in the presence of sucrose (p < 0.01). To study any ensuing functional/phenotypical links between SMU.243 and uppP, which is located immediately downstream of SMU.243 and encodes an undecaprenyl pyrophosphate phosphatase involved in recycling of carrier lipid undecaprenyl phosphate, a uppP deficient mutant was generated using allelic exchange mutagenesis. Unlike the SMU.243 mutant, deletion of uppP affected cell envelope biogenesis and caused major increases in susceptibility to bacitracin. In addition, two variant morphological mutants, one forming rough colonies and the other forming mucoid, smooth colonies, also emerged following the deletion of uppP. The results suggest that the SMU.243-encoded protein of the DUF2207 family in S. mutans plays an important role in stress tolerance response and biofilm formation, but unlike the downstream uppP, does not seem to be involved in cell envelope biogenesis, although the exact roles in S. mutans’ physiology awaits further investigation.

A Qualitative Analysis Of Candida Auris Laboratory Surveillance In Nebraska, Lissa M. Young

Capstone Experience: Master of Public Health

Objectives: Candida auris is an emerging pathogenic yeast that was first identified in Japan in 2009 and detected in the United States in 2015. As of 2020, C. auris has been reported in cases throughout 41 countries, including the United States. The ability of this species of yeast to spread rapidly and survive for long periods of time on surfaces, the high mortality rate of those infected, and its multidrug resistant phenotype, have rendered it a urgent public health threat (the highest threat level) by the United States Centers for Disease Control and Prevention beginning in 2019 (CDC, 2019). Since …

Chromatin Architectural Factor Ctcf Is Essential For Progesterone-Dependent Uterine Maturation, Sylvia C Hewitt, Artiom Gruzdev, Cynthia J Willson, San-Pin Wu, John P Lydon, Niels Galjart, Francesco J Demayo

Faculty, Staff and Students Publications

Receptors for estrogen and progesterone frequently interact, via Cohesin/CTCF loop extrusion, at enhancers distal from regulated genes. Loss-of-function CTCF mutation in >20% of human endometrial tumors indicates its importance in uterine homeostasis. To better understand how CTCF-mediated enhancer-gene interactions impact endometrial development and function, the Ctcf gene was selectively deleted in female reproductive tissues of mice. Prepubertal Ctcf

Barriers And Facilitators To Home Dialysis Among Latinx Patients With Kidney Disease, Katherine Rizzolo, Rebeca Gonzalez Jauregui, Ileana Barrientos, Jade Teakell, Claudia Camacho, Michel Chonchol, Sushrut S Waikar, Lilia Cervantes

Faculty, Staff and Student Publications

Importance: Latinx people have a high burden of kidney disease but are less likely to receive home dialysis compared to non-Latinx White people. The disparity in home dialysis therapy has not been completely explained by demographic, medical, or social factors.

Objective: To understand the barriers and facilitators to home dialysis therapy experienced by Latinx individuals with kidney failure receiving home dialysis.

Design, setting, and participants: This qualitative study used semistructured interviews with Latinx adults with kidney failure receiving home dialysis therapy in Denver, Colorado, and Houston, Texas, between November 2021 and March 2023. Patients were recruited from home dialysis clinics …

Gwas-Identified Telomere Length Associated Genetic Variants Predict Risk Of Recurrence Of Hpv-Positive Oropharyngeal Cancer After Definitive Radiotherapy, Peng Sun, Peng Wei, Hongliang Liu, Jia Wu, Neil D Gross, Andrew G Sikora, Qingyi Wei, Sanjay Shete, Mark E Zafereo, Jisheng Liu, Guojun Li

Faculty, Staff and Student Publications

Background: Lymphocyte telomere length (LTL)-related genetic variants may modulate LTL and affect recurrence of squamous cell carcinoma of the oropharynx (SCCOP).

Methods: A total of 1013 patients with incident SCCOP were recruited and genotyped for 16 genome-wide association study (GWAS)-identified TL-related polymorphisms. Of these patients, 489 had tumour HPV16 status determination. Univariate and multivariate analyses were performed to evaluate associations.

Findings: Of the 16 TL-related polymorphisms, four were significantly associated with LTL: rs1920116, rs3027234, rs6772228, and rs11125529, and the patients with putatively favourable genotypes had approximately 1.5-3 times the likelihood of shorter LTL compared with patients with the corresponding risk …

Heterogeneity Of The Group B Streptococcal Type Vii Secretion System And Influence On Colonization Of The Female Genital Tract, Brady L Spencer, Alyx M Job, Clare M Robertson, Zainab A Hameed, Camille Serchejian, Caitlin S Wiafe-Kwakye, Jéssica C Mendonça, Morgan A Apolonio, Prescilla E Nagao, Melody N Neely, Natalia Korotkova, Konstantin V Korotkov, Kathryn A Patras, Kelly S Doran

Faculty, Staff and Students Publications

Type VIIb secretion systems (T7SSb) in Gram-positive bacteria facilitate physiology, interbacterial competition, and/or virulence via EssC ATPase-driven secretion of small ɑ-helical proteins and toxins. Recently, we characterized T7SSb in group B Streptococcus (GBS), a leading cause of infection in newborns and immunocompromised adults. GBS T7SS comprises four subtypes based on variation in the C-terminus of EssC and the repertoire of downstream effectors; however, the intraspecies diversity of GBS T7SS and impact on GBS-host interactions remains unknown. Bioinformatic analysis indicates that GBS T7SS loci encode subtype-specific putative effectors, which have low interspecies and inter-subtype homology but contain similar domains/motifs and therefore …

Deconvolution Of Cancer Cell States By The Xdec-Sm Method, Oscar D Murillo, Varduhi Petrosyan, Emily L Laplante, Lacey E Dobrolecki, Michael T Lewis, Aleksandar Milosavljevic

Faculty, Staff and Students Publications

Proper characterization of cancer cell states within the tumor microenvironment is a key to accurately identifying matching experimental models and the development of precision therapies. To reconstruct this information from bulk RNA-seq profiles, we developed the XDec Simplex Mapping (XDec-SM) reference-optional deconvolution method that maps tumors and the states of constituent cells onto a biologically interpretable low-dimensional space. The method identifies gene sets informative for deconvolution from relevant single-cell profiling data when such profiles are available. When applied to breast tumors in The Cancer Genome Atlas (TCGA), XDec-SM infers the identity of constituent cell types and their proportions. XDec-SM also …