Medical Microbiology Commons^™

Microbial Interactions Among Gardnerella, Prevotella And Fannyhessea Prior To Incident Bacterial Vaginosis: Protocol For A Prospective, Observational Study, Christina A. Muzny, Jacob H. Elnaggar, Lúcia G.V. Sousa, Ângela Lima, Kristal J. Aaron, Isaac C. Eastlund, Keonte J. Graves, Chaoling Dong, Olivia T. Van Gerwen, Meng Luo, Ashutosh Tamhane, Dustin Long, Nuno Cerca, Christopher M. Taylor

School of Graduate Studies Faculty Publications

Introduction The aetiology of bacterial vaginosis (BV), a biofilm-associated vaginal infection, remains unknown. Epidemiologic data suggest that it is sexually transmitted. BV is characterised by loss of lactic acid-producing lactobacilli and an increase in facultative and strict anaerobic bacteria. Gardnerella spp are present in 95%–100% of cases; Gardnerella vaginalis has been found to be more virulent than other BV-associated bacteria (BVAB) in vitro. However, G. vaginalis is found in women with normal vaginal microbiota and colonisation is not sufficient for BV development. We hypothesise that Gardnerella spp initiate BV biofilm formation, but incident BV (iBV) requires incorporation of other key …

Genome-Wide P63-Target Gene Analyses Reveal Tap63/Nrf2-Dependent Oxidative Stress Responses, Marco Napoli, Avani A Deshpande, Deepavali Chakravarti, Kimal Rajapakshe, Preethi H Gunaratne, Cristian Coarfa, Elsa R Flores

Faculty, Staff and Students Publications

The p53 family member TP63 encodes two sets of N-terminal isoforms, TAp63 and ΔNp63 isoforms. They each regulate diverse biological functions in epidermal morphogenesis and in cancer. In the skin, where their activities have been extensively characterized, TAp63 prevents premature aging by regulating the quiescence and genomic stability of stem cells required for wound healing and hair regeneration, while ΔNp63 controls maintenance and terminal differentiation of epidermal basal cells. This functional diversity is surprising given that these isoforms share a high degree of similarity, including an identical sequence for a DNA-binding domain. To understand the mechanisms of the transcriptional programs …

Respiratory Viral Detection In The Plasma And Cerebrospinal Fluid (Csf) Of Young Febrile Infants, Erin G Nicholson, Vasanthi Avadhanula, Leila C Sahni, Laura Ferlic-Stark, Lauren Maurer, Julie A Boom, Pedro A Piedra

Faculty, Staff and Students Publications

BACKGROUND: Respiratory viral infections are common in febrile infants ≤90 days. However, the detection of viruses other than enterovirus in the blood and cerebrospinal fluid (CSF) of young infants is not well defined. We sought to quantify the occurrence of respiratory viruses in the blood and CSF of febrile infants ≤90 days.

METHODS: We conducted a nested cohort study examining plasma and CSF samples from febrile infants 15-90 days via rtPCR. The samples were tested for respiratory viruses (respiratory syncytial virus, influenza, enterovirus, parechovirus, adenovirus, bocavirus). Clinical and laboratory data were also collected to determine the presence of serious bacterial …

A Kinesin-13 Family Kinesin In Trypanosoma Brucei Regulates Cytokinesis And Cytoskeleton Morphogenesis By Promoting Microtubule Bundling, Huiqing Hu, Yasuhiro Kurasawa, Qing Zhou, Ziyin Li

Faculty, Staff and Student Publications

The early branching eukaryote Trypanosoma brucei divides uni-directionally along the longitudinal cell axis from the cell anterior toward the cell posterior, and the cleavage furrow ingresses along the cell division plane between the new and the old flagella of a dividing bi-flagellated cell. Regulation of cytokinesis in T. brucei involves actomyosin-independent machineries and trypanosome-specific signaling pathways, but the molecular mechanisms underlying cell division plane positioning remain poorly understood. Here we report a kinesin-13 family protein, KIN13-5, that functions downstream of FPRC in the cytokinesis regulatory pathway and determines cell division plane placement. KIN13-5 localizes to multiple cytoskeletal structures, interacts …

Comprehensive Characterization Of Polyproline Tri-Helix Macrocyclic Nanoscaffolds For Predictive Ligand Positioning, Chia-Lung Tsai, Je-Wei Chang, Kum-Yi Cheng, Yu-Jing Lan, Yi-Cheng Hsu, Qun-Da Lin, Tzu-Yuan Chen, Orion Shih, Chih-Hsun Lin, Po-Hsun Chiang, Mantas Simenas, Vidmantas Kalendra, Yun-Wei Chiang, Chun-Hsien Chen, U-Ser Jeng, Sheng-Kai Wang

Faculty, Staff and Student Publications

Multivalent ligands hold promise for enhancing avidity and selectivity to simultaneously target multimeric proteins, as well as potentially modulating receptor signaling in pharmaceutical applications. Essential for these manipulations are nanosized scaffolds that precisely control ligand display patterns, which can be achieved by using polyproline oligo-helix macrocyclic nanoscaffolds via selective binding to protein oligomers and cell surface receptors. This work focuses on synthesis and structural characterization of different-sized polyproline tri-helix macrocyclic (PP3M) scaffolds. Through combined analysis of circular dichroism (CD), small- and wide-angle X-ray scattering (SWAXS), electron spin resonance (ESR) spectroscopy, and molecular modeling, a non-coplanar tri-helix loop structure with partially …

Autophagy And Cell Wall Integrity Pathways Coordinately Regulate The Development And Pathogenicity Through Moatg4 Phosphorylation In Magnaporthe Oryzae, Pusheng Guo, Yurong Wang, Jiayun Xu, Zhixiang Yang, Ziqi Zhang, Jinyi Qian, Jiexiong Hu, Ziyi Yin, Leiyun Yang, Muxing Liu, Xinyu Liu, Gang Li, Haifeng Zhang, Ryan Rumsey, Ping Wang, Zhengguang Zhang

School of Medicine Faculty Publications

Autophagy and Cell wall integrity (CWI) signaling are critical stress-responsive processes during fungal infection of host plants. In the rice blast fungus Magnaporthe oryzae, autophagy-related (ATG) proteins phosphorylate CWI kinases to regulate virulence; however, how autophagy interplays with CWI signaling to coordinate such regulation remains unknown. Here, we have identified the phosphorylation of ATG protein MoAtg4 as an important process in the coordination between autophagy and CWI in M. oryzae. The ATG kinase MoAtg1 phosphorylates MoAtg4 to inhibit the deconjugation and recycling of the key ATG protein MoAtg8. At the same time, MoMkk1, a core kinase of CWI, also phosphorylates …

Important Features For Protein Foldings In Two Acyl Carrier Proteins From Enterococcus Faecalis, Seoyeong Yoo, Jiwon Yeon, Eunhee Kim, Yangmee Kim

Faculty, Staff and Student Publications

The emergence of multi-drug resistant Enterococcus faecalis raises a serious threat to global public health. E. faecalis is a gram-positive intestinal commensal bacterium found in humans. E. faecalis can endure extreme environments such as high temperature, pressure, and high salt, which facilitates them to cause infection in hospitals. E. faecalis has two acyl carrier proteins, AcpA (EfAcpA) in de novo fatty acid synthesis (FAS) and AcpB (EfAcpB) which utilizes exogenous fatty acids. Previously, we determined the tertiary structures of these two ACPs and investigated their structure-function relationships. Solution structures revealed that overall folding of these two ACPs is similar to …

Targeted Repression Of Topa By Crispri Reveals A Critical Function For Balanced Dna Topoisomerase I Activity In The Chlamydia Trachomatis Developmental Cycle, Li Shen, Leiqiong Gao, Abigail R. Swoboda, Scot P. Ouellette

School of Medicine Faculty Publications

Chlamydia trachomatis is an obligate intracellular bacterium that is responsible for the most prevalent bacterial sexually transmitted infection. Changes in DNA topology in this pathogen have been linked to its pathogenicity-associated developmental cycle. Here, evidence is provided that the balanced activity of DNA topoisomerases contributes to controlling Chlamydia developmental processes. Utilizing catalytically inactivated Cas12 (dCas12)-based clustered regularly interspaced short palindromic repeats interference (CRISPRi) technology, we demonstrate targeted knockdown of chromosomal topA transcription in C. trachomatis without detected toxicity of dCas12. Repression of topA impaired the developmental cycle of C. trachomatis mostly through disruption of its differentiation from a replicative form …

Characterization Of Variant Rnas Encapsidated During Bromovirus Infection By High-Throughput Sequencing, Sarah Dexheimer, Nipin Shrestha, Bandana Sharma Chapagain, Jozef J. Bujarski, Yanbin Yin

Food for Health: Publications

Previously, we described the RNA recombinants accumulating in tissues infected with the bromoviruses BMV (Brome mosaic virus) and CCMV (Cowpea chlorotic mottle virus). In this work, we characterize the recombinants encapsidated inside the purified virion particles of BMV and CCMV. By using a tool called the Viral Recombination Mapper (ViReMa) that detects recombination junctions, we analyzed a high number of high-throughput sequencing (HTS) short RNA sequence reads. Over 28% of BMV or CCMV RNA reads did not perfectly map to the viral genomes. ViReMa identified 1.40% and 1.83% of these unmapped reads as the RNA recombinants, respectively, in BMV and …

Interplay Between Acetylation And Ubiquitination Of Imitation Switch Chromatin Remodeler Isw1 Confers Multidrug Resistance In Cryptococcus Neoformans, Yang Meng, Yue Ni, Zhuoran Li, Tianhang Jiang, Tianshu Sun, Yanjian Li, Xindi Gao, Hailong Li, Chenhao Suo, Chao Li, Sheng Yang, Tian Lan, Guojian Liao, Tongbao Liu, Ping Wang, Chen Ding

School of Medicine Faculty Publications

Cryptococcus neoformans poses a threat to human health, but anticryptococcal therapy is hampered by the emergence of drug resistance, whose underlying mechanisms remain poorly understood. Herein, we discovered that Isw1, an imitation switch chromatin remodeling ATPase, functions as a master modulator of genes responsible for in vivo and in vitro multidrug resistance in C. neoformans. Cells with the disrupted ISW1 gene exhibited profound resistance to multiple antifungal drugs. Mass spectrometry analysis revealed that Isw1 is both acetylated and ubiquitinated, suggesting that an interplay between these two modification events exists to govern Isw1 function. Mutagenesis studies of acetylation and ubiquitination sites …

Targeted Treatment For Kras12d For Pdac Treatment, Ana Bulnes, Orlando Garcia, Poornima Devi Shaji, Melissa Elizondo, Swathi Holla, Nirnoy Dan, Anupam Dhasmana, Shabnam Malik, Murali Yallapu, Stephen Behrman

Research Symposium

Introduction: Cellular stress is known to function in synergistic cooperation with oncogenic mutations during tumorigenesis to drive cancer progression. Oncogenic RAS is a strong inducer of a variety of pro-tumorigenic cellular stresses, and also enhances the ability of cells to tolerate these stresses through multiple mechanisms that leads to resistance to chemotherapy and to therapies that target the RAS pathway. Pancreatic Ductal Adenocarcinoma (PDAC) patients exhibit extremely poor prognosis. KRAS mutation on codon-12 is present in 70–95% of PDAC cases and it drives stress-adaptive mechanisms, PDAC growth and progression. Galectin-1 (Gal-1) is present in both PDAC and stromal cells, being …

Studying The Molecular Mechanism Of Hepatocellular Carcinoma, Shabnam Malik, Mohammed Sikander, S. Mishra, Daniel Zubieta, S. K. Jain, Deepshikha Pande Katare, Meena Jaggi, Subhash Chauhan

Research Symposium

Background: Hepatocellular carcinoma (HCC) has a poor prognosis due to ineffective therapeutic modality and lack of early diagnostic marker. Accumulating studies have shown that elevated expression of mucin 13 as potential oncogene and predictive biomarker for various cancer. However, very little is known about its expression and function for development and progression of HCC.

Objective: To investigate mucin 13 expression in chemically induced hepatocellular carcinoma model.

Methodology: Diethyl nitrosamine (DEN) and 2-Acetylaminofluorene (2-AAF) induced method was employed for the development of hepatocellular carcinoma in Male Wistar rats. Serum and tissues were collected at regular intervals of time and routinely validated …

Comparison Of Three Rapid Diagnostic Tests For Bloodstream Infections Using Benefit-Risk Evaluation Framework (Bed-Frame), Richard D Smith, Min Zhan, Shanshan Zhang, Surbhi Leekha, Anthony Harris, Yohei Doi, Scott Evans, J Kristie Johnson, Robert K Ernst

Faculty, Staff and Student Publications

Rapid diagnostic tests (RDTs) for bloodstream infections have the potential to reduce time to appropriate antimicrobial therapy and improve patient outcomes. Previously, an in-house, lipid-based, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) method, Fast Lipid Analysis Technique (FLAT MS), has shown promise as a rapid pathogen identification method. In this study, FLAT MS for direct from blood culture identification was evaluated and compared to FDA-cleared identification methods using the Benefit-risk Evaluation Framework (BED-FRAME) analysis. FLAT MS was evaluated and compared to Bruker Sepsityper and bioMérieux BioFire FilmArray BCID2 using results from a previous study. For this study, 301 …

A Novel Erβ High Throughput Microscopy Platform For Testing Endocrine Disrupting Chemicals, Derek A Abbott, Maureen G Mancini, Michael J Bolt, Adam T Szafran, Kaley A Neugebauer, Fabio Stossi, Daniel A Gorelick, Michael A Mancini

Faculty, Staff and Students Publications

In this study we present an inducible biosensor model for the Estrogen Receptor Beta (ERβ), GFP-ERβ:PRL-HeLa, a single-cell-based high throughput (HT) in vitro assay that allows direct visualization and measurement of GFP-tagged ERβ binding to ER-specific DNA response elements (EREs), ERβ-induced chromatin remodeling, and monitor transcriptional alterations via mRNA fluorescence in situ hybridization for a prolactin (PRL)-dsRED2 reporter gene. The model was used to accurately (Z' = 0.58-0.8) differentiate ERβ-selective ligands from ERα ligands when treated with a panel of selective agonists and antagonists. Next, we tested an Environmental Protection Agency (EPA)-provided set of 45 estrogenic reference chemicals with known …

Fbpp: Software To Design Pcr Primers And Probes For Nucleic Acid Base Detection Of Foodborne Pathogens, Mohamed A Soliman, Mohamed S Azab, Hala A Hussein, Mohamed M Roushdy, Mohamed N Abu El-Naga

Faculty, Staff and Student Publications

Foodborne pathogens can be found in various foods, and it is important to detect foodborne pathogens to provide a safe food supply and to prevent foodborne diseases. The nucleic acid base detection method is one of the most rapid and widely used methods in the detection of foodborne pathogens; it depends on hybridizing the target nucleic acid sequence to a synthetic oligonucleotide (probes or primers) that is complementary to the target sequence. Designing primers and probes for this method is a preliminary and critical step. However, new bioinformatics tools are needed to automate, specific and improve the design sets to …

Rare Case Of Mycobacterium Avium Complex Peritonitis In A Patient With Multiple Myeloma Undergoing Peritoneal Dialysis, Sacide S. Ozgur, Nida Ansari, Dhruv Patel, Ryan Rahman, Raymond Shih

Journal of Community Hospital Internal Medicine Perspectives

Mycobacterium avium complex (MAC) infections can present as a variety of severe diseases. While it has a predilection for immunocompromised patients such as those with Human immunodeficiency virus (HIV), it can also affect immunocompetent patients as well. One of the rare yet severe diseases that MAC infections can present is MAC peritonitis. Often hard to distinguish from other causes of peritonitis, high clinical suspicion should be maintained for those who are susceptible. Here we present an 85-year-old female with a past medical history of end-stage renal disease on peritoneal dialysis who presented with nausea and vomiting. She was found to …

Antibiotic-Induced Gut Dysbiosis Elicits Gut-Brain Axis Relevant Multi-Omic Signatures And Behavioral And Neuroendocrine Changes In A Nonhuman Primate Model, Shivdeep S. Hayer, Mackenzie Conrin, Jeffrey French, Andrew K. Benson, Sophie Alvarez, Kathryn Dempsey, Anne Fischer, Zahraa Wajih Alsafwani, William Gasper, Mallory J. Suhr Van Haute, Haley R. Hassenstab, Shayda Azadmanesh, Missy Briardy, Skyler Gerbers, Aliyah Jabenis, Jennifer L. Thompson, Jonathan B. Clayton

Food for Health: Publications

Emerging evidence indicates that antibiotic-induced dysbiosis can play an etiological role in the pathogenesis of neuropsychiatric disorders. However, most of this evidence comes from rodent models. The objective of this study was to evaluate if antibiotic-induced gut dysbiosis can elicit changes in gut metabolites and behavior indicative of gut-brain axis disruption in common marmosets (Callithrix jacchus) – a nonhuman primate model often used to study sociability and stress. We were able to successfully induce dysbiosis in marmosets using a custom antibiotic cocktail (vancomycin, enrofloxacin and neomycin) administered orally for 28 days. This gut dysbiosis altered gut metabolite profiles, …

Gut Epithelial Interleukin-17 Receptor A Signaling Can Modulate Distant Tumors Growth Through Microbial Regulation, Vidhi Chandra, Le Li, Olivereen Le Roux, Yu Zhang, Rian M Howell, Dhwani N Rupani, Seyda Baydogan, Haiyan D Miller, Erick Riquelme, Joseph Petrosino, Michael P Kim, Krishna P L Bhat, James R White, Jay K Kolls, Yuliya Pylayeva-Gupta, Florencia Mcallister

Faculty, Staff and Student Publications

Microbes influence cancer initiation, progression and therapy responsiveness. IL-17 signaling contributes to gut barrier immunity by regulating microbes but also drives tumor growth. A knowledge gap remains regarding the influence of enteric IL-17-IL-17RA signaling and their microbial regulation on the behavior of distant tumors. We demonstrate that gut dysbiosis induced by systemic or gut epithelial deletion of IL-17RA induces growth of pancreatic and brain tumors due to excessive development of Th17, primary source of IL-17 in human and mouse pancreatic ductal adenocarcinoma, as well as B cells that circulate to distant tumors. Microbial dependent IL-17 signaling increases DUOX2 signaling in …

Preclinical Repurposing Of Sitagliptin As A Drug Candidate For Colorectal Cancer By Targeting Cd24/Ctnnb1/Sox4-Centered Signaling Hub, Jing-Wen Shih, Alexander T H Wu, Ntlotlang Mokgautsi, Po-Li Wei, Yan-Jiun Huang

Faculty, Staff and Student Publications

Despite significant advances in treatment modalities, colorectal cancer (CRC) remains a poorly understood and highly lethal malignancy worldwide. Cancer stem cells (CSCs) and the tumor microenvironment (TME) have been shown to play critical roles in initiating and promoting CRC progression, metastasis, and treatment resistance. Therefore, a better understanding of the underlying mechanisms contributing to the generation and maintenance of CSCs is crucial to developing CSC-specific therapeutics and improving the current standard of care for CRC patients. To this end, we used a bioinformatics approach to identify increased CD24/SOX4 expression in CRC samples associated with poor prognosis. We also …

Conserved Residues At The Mtr4 C-Terminus Coordinate Helicase Activity And Exosome Interactions, Matthew K Yim, Catherine J Stuart, Markell I Pond, Ambro Van Hoof, Sean J Johnson

Faculty, Staff and Student Publications

Mtr4 is an essential RNA helicase involved in nuclear RNA processing and degradation and is a member of the Ski2-like helicase family. Ski2-like helicases share a common core architecture that includes two RecA-like domains, a winged helix, and a helical bundle (HB) domain. In Mtr4, a short C-terminal tail immediately follows the HB domain and is positioned at the interface of the RecA-like domains. The tail ends with a SLYΦ sequence motif that is highly conserved in a subset of Ski2-like helicases. Here, we show that this sequence is critical for Mtr4 function. Mutations in the C-terminus result in decreased …

Appelmans Protocol – A Directed In Vitro Evolution Enables Induction And Recombination Of Prophages With Expanded Host Range, Thao Nguyen Vu, Justin Ryan Clark, Eris Jang, Roshan D'Souza, Le Phuong Nguyen, Naina Adren Pinto, Seongjun Yoo, Ricardo Abadie, Anthony William Maresso, Dongeun Yong

Faculty, Staff and Students Publications

Infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) present significant healthcare challenges due to limited treatment options. Bacteriophage (phage) therapy offers potential as an alternative treatment. However, the high host specificity of phages poses challenges for their therapeutic application. To broaden the phage spectrum, laboratory-based phage training using the Appelmans protocol was employed in this study. As a result, the protocol successfully expanded the host range of a phage cocktail targeting CRAB. Further analysis revealed that the expanded host range phages isolated from the output cocktail were identified as recombinant derivatives originating from prophages induced from encountered bacterial strains. These findings …

Metabolism Shapes Immune Responses To Staphylococcus Aureus., Prabhakar Arumugam, Tammy Kielian

Journal Articles: Pathology and Microbiology

BACKGROUND: Staphylococcus aureus (S. aureus) is a common cause of hospital- and community-acquired infections that can result in various clinical manifestations ranging from mild to severe disease. The bacterium utilizes different combinations of virulence factors and biofilm formation to establish a successful infection, and the emergence of methicillin- and vancomycin-resistant strains introduces additional challenges for infection management and treatment.

SUMMARY: Metabolic programming of immune cells regulates the balance of energy requirements for activation and dictates pro- versus anti-inflammatory function. Recent investigations into metabolic adaptations of leukocytes and S. aureus during infection indicate that metabolic crosstalk plays a crucial role in …

Elucidating Granulocytic Myeloid-Derived Suppressor Cell Heterogeneity During Staphylococcus Aureus Biofilm Infection, Blake P. Bertrand, Cortney E. Heim, Scott A. Koepsell, Tammy Kielian

Journal Articles: Pathology and Microbiology

Myeloid-derived suppressor cells (MDSCs) are pathologically activated immature myeloid cells with immunosuppressive activity that expand during chronic inflammation, such as cancer and prosthetic joint infection (PJI). Myeloid-derived suppressor cells can be broadly separated into 2 populations based on surface marker expression and function: monocytic myeloid-derived suppressor cells (M-MDSCs) and granulocytic myeloid-derived suppressor cells (G-MDSCs). Granulocytic myeloid-derived suppressor cells are the most abundant leukocyte infiltrate during PJI; however, how this population is maintained in vivo and cellular heterogeneity is currently unknown. In this study, we identified a previously unknown population of Ly6G+Ly6C+F4/80+MHCII+ MDSCs during PJI that displayed immunosuppressive properties ex vivo. …

C1q Is Elevated During Chronic Staphylococcus Epidermidis Central Nervous System Catheter Infection, Matthew K. Beaver, Lara Bergdolt, Anna Dunaevsky, Tammy Kielian, Gwenn Skar

Journal Articles: Pathology and Microbiology

INTRODUCTION: Significant neurologic morbidity is caused by pediatric cerebrospinal fluid (CSF) shunt infections. The underlying mechanisms leading to impaired school performance and increased risk of seizures are unknown, however, a better understanding of these mechanisms may allow us to temper their consequences. Recent evidence has demonstrated important roles for complement proteins in neurodevelopment and neuroinflammation.

METHODS: We examined complement activation throughout

RESULTS: We found that MASP2 predominated early in catheter infection, but that Factor B was elevated at intermediate time points. Unexpectedly C1q was elevated at late timepoints when bacterial burdens were low or undetectable. Based on these findings and …

Antimicrobial Activity Of Gallium(Iii) Compounds: Pathogen-Dependent Targeting Of Multiple Iron/Heme-Dependent Biological Processes, Seoung-Ryoung Choi, Mohammed A. Hassan, Bradley E. Britigan, Prabagaran Narayanasamy

Journal Articles: Pathology and Microbiology

Metals play vital roles in biological systems, with iron/heme being essential for cellular and metabolic functions necessary for survival and/or virulence in many bacterial pathogens. Given the rise of bacterial resistance to current antibiotics, there is an urgent need for the development of non-toxic and novel antibiotics that do not contribute to resistance to other antibiotics. Gallium, which mimics iron, has emerged as a promising antimicrobial agent, offering a novel approach to combat bacterial infections. Gallium does not have any known functions in biological systems. Gallium exerts its effects primarily by replacing iron in redox enzymes, effectively inhibiting bacterial growth …

Aconitate Decarboxylase 1 Mediates The Acute Airway Inflammatory Response To Environmental Exposures, Aaron Schwab, Amy J. Nelson, Angela Gleason, Oliver Schanze, Todd A. Wyatt, Dhananjay Shinde, Peng Xiao, Vinai Chittezham Thomas, Chittibabu Guda, Kristina L. Bailey, Tammy Kielian, Geoffrey M. Thiele, Jill A. Poole

Journal Articles: Pathology and Microbiology

Background: Environmental lipopolysaccharide (LPS) and microbial component-enriched organic dusts cause significant lung disease. These environmental exposures induce the recruitment and activation of distinct lung monocyte/macrophage subpopulations involved in disease pathogenesis. Aconitate decarboxylase 1 (Acod1) was one of the most upregulated genes following LPS (vs. saline)exposure of murine whole lungs with transcriptomic profiling of sorted lung monocyte/macrophage subpopulations also highlighting its significance. Given monocyte/macrophage activation can be tightly linked to metabolism, the objective of these studies was to determine the role of the immunometabolic regulator ACOD1 inenvironmentalexposure-induced lung inflammation.

Methods: Wild-type (WT) mice were intratracheally (i.t.) instilled with 10 …

Bacterial Single-Cell Rna Sequencing Captures Biofilm Transcriptional Heterogeneity And Differential Responses To Immune Pressure, Lee E. Korshoj, Tammy Kielian

Journal Articles: Pathology and Microbiology

Biofilm formation is an important mechanism of survival and persistence for many bacterial pathogens. These multicellular communities contain subpopulations of cells that display metabolic and transcriptional diversity along with recalcitrance to antibiotics and host immune defenses. Here, we present an optimized bacterial single-cell RNA sequencing method, BaSSSh-seq, to study Staphylococcus aureus diversity during biofilm growth and transcriptional adaptations following immune cell exposure. BaSSSh-seq captures extensive transcriptional heterogeneity during biofilm compared to planktonic growth. We quantify and visualize transcriptional regulatory networks across heterogeneous biofilm subpopulations and identify gene sets that are associated with a trajectory from planktonic to biofilm growth. BaSSSh-seq …

Metabolic Diversity Of Human Macrophages: Potential Influence On Staphylococcus Aureus Intracellular Survival, Blake P. Bertrand, Dhananjay Shinde, Vinai C. Thomas, Marvin Whiteley, Carolyn B. Ibberson, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a leading cause of medical device-associated biofilm infections. This is influenced by the ability of S. aureus biofilm to evade the host immune response, which is partially driven by the anti-inflammatory cytokine interleukin-10 (IL-10). Here, we show that treatment of human monocyte-derived macrophages (HMDMs) with IL-10 enhanced biofilm formation, suggesting that macrophage anti-inflammatory programming likely plays an important role during the transition from planktonic to biofilm growth. To identify S. aureus genes that were important for intracellular survival in HMDMs and how this was affected by IL-10, transposon sequencing was performed. The size of the S. aureus …

Dual Gallium Drug Treatment Against Carbapenem-Resistant Klebsiella Pneumoniae: Efficacy And Potential Mechanism(S) Of Action And Resistance, Zachary Scott, Seoung-Ryoung Choi, Bradley E. Britigan, Prabagaran Narayanasamy

Journal Articles: Pathology and Microbiology

Klebsiella pneumoniae (KLP) is a Gram-negative pathogen that can be highly antibiotic-resistant. Our group has worked with gallium-based compounds as a means of treating bacterial infections. Here the possible mechanism is investigated for dual therapy comprised of gallium nitrate (Ga(NO₃)₃) and gallium protoporphyrin (GaPP) on KLP. It is found that in vitro the combination of Ga(NO₃)₃ and GaPP is synergistic against KLP. The in vivo efficacy is of the dual therapy is additionally tested by treating pulmonary KLP infections in mice. Much greater effectiveness are observed in bacterial clearance and survival of mice …

Tetracycline And Oxacillin Act Synergistically On Biofilms And Display Increased Efficacy In Vivo Against Staphylococcus Aureus, Amy K. Tooke, Rebecca E. Hodges, Josie F. Pyrah, Kenneth W. Bayles, Stephen A. Renshaw, Simon J. Foster

Journal Articles: Pathology and Microbiology

Oxacillin (bactericidal) and tetracycline (bacteriostatic) are clinically relevant antibiotics that are routinely prescribed to treat Staphylococcus aureus infections but not conventionally used in combination. There is an urgent need for treatment regimens that can act upon biofilms during infection, associated with chronic infections on indwelling devices, as well as acute planktonic (systemic) infection. Here we show that in an in vitro model oxacillin and tetracycline act synergistically against S. aureus UAMS-1 biofilms, reducing the concentration of both antibiotics necessary to eradicate an established biofilm. Using an in vivo zebrafish larval infection model with S. aureus NewHG, they display improved bacterial …