Bacterial Infections and Mycoses Commons^™

Iiv-6 Inhibits Nf-Kappab Responses In Drosophila, Cara C. West, Florentina Rus, Ying Chen, Anni Kleino, Monique Gangloff, Don B. Gammon, Neal S. Silverman

Neal Silverman

The host immune response and virus-encoded immune evasion proteins pose constant, mutual selective pressure on each other. Virally encoded immune evasion proteins also indicate which host pathways must be inhibited to allow for viral replication. Here, we show that IIV-6 is capable of inhibiting the two Drosophila NF-kappaB signaling pathways, Imd and Toll. Antimicrobial peptide (AMP) gene induction downstream of either pathway is suppressed when cells infected with IIV-6 are also stimulated with Toll or Imd ligands. We find that cleavage of both Imd and Relish, as well as Relish nuclear translocation, three key points in Imd signal transduction, occur …

Use Of Urine Antigen Testing For Blastomyces In An Integrated Health System, Dennis J. Baumgardner

Dennis J. Baumgardner, MD

Purpose: Blastomycosis, an endemic fungal infection, mimics many other diseases. We explored the use of Blastomyces urine antigen (BuAg), reportedly the most sensitive noninvasive test, in clinical practice and compared it to other noninvasive tests.

Methods: A total of 836 BuAg tests performed on unique patients (first test only) at one large integrated health system from June 2013 to May 2016 were retrospectively reviewed to examine test characteristics and demographic features. Of these, 100 cases from 2015, a year containing a large local blastomycosis outbreak, were randomly selected for detailed analysis.

Results: Demographics for the BuAg-tested population: mean age 54.9 …

Fmt Placed By Colonoscopy: Systematic Review And Meta-Analysis, Nadia Huq, Veena Kumaravel, Aboud Affi, Maharaj Singh

Aurora Gastroenterology Faculty

Background: Fecal transplants are successful in the treatment of recurrent or refractory Clostridium difficile infections (CDI), but there is no consensus on the best method of instillation. Studies have shown greater success with lower gastrointestinal tract placement, but technical aspects of placement are not validated.

Purpose: This review aims to identify common traits and procedural techniques of successful fecal microbiota transplant (FMT) therapy via colonoscopy.

Methods: An electronic search was conducted using OVID Medline and PubMed for articles published from January 2010 to January 2016. The primary outcome of interest was cure by FMT placed via colonoscopy.

Results: Of the …

Superbugs Versus Outsourced Cleaners: Employment Arrangements And The Spread Of Health Care-Associated Infections, Adam Seth Litwin, Ariel C. Avgar, Edmund R. Becker

Adam Seth Litwin

On any given day, about one in 25 hospital patients in the United States has a health care–associated infection (HAI) that the patient contracts as a direct result of his or her treatment. Fortunately, the spread of most HAIs can be halted through proper disinfection of surfaces and equipment. Consequently, cleaners—“environmental services” (EVS) in hospital parlance—must take on the important task of defending hospital patients (as well as staff and the broader community) from the spread of HAIs. Despite the importance of this task, hospitals frequently outsource this function, increasing the likelihood that these workers are under-rewarded, undertrained, and detached …

Burkholderia Pseudomallei Enters The Brain And Spinal Cord Via The Trigeminal Nerve, Heidi Walkden, James St John, Lynn Nazareth, Jenny Ekberg

Jenny Ekberg

Background

The trigeminal nerve is the largest cranial nerve responsible for sensation in the face and motor functions such as chewing. It constitutes a direct route from the nasal cavity into the brain (Fig. 1). Despite this, only a handful of microorganisms are thought to infect the brain via this route.

The tropical disease melioidosis caused by Burkholderia pseudomallei is endemic to the northern Australia and south-east Asia. The main route of transmission is via inhalation of droplets and soil. The Australian variant can result in brain infection, but the mechanism of infection is unknown.

Here, we investigated whether …

Fungal Infections From Human And Animal Contact, Dennis J. Baumgardner

Dennis J. Baumgardner, MD

Fungal infections in humans resulting from human or animal contact are relatively uncommon, but they include a significant proportion of dermatophyte infections. Some of the most commonly encountered diseases of the integument are dermatomycoses. Human or animal contact may be the source of all types of tinea infections, occasional candidal infections, and some other types of superficial or deep fungal infections. This narrative review focuses on the epidemiology, clinical features, diagnosis and treatment of anthropophilic dermatophyte infections primarily found in North America. Other human-acquired and zoonotic fungal infections also are discussed in brief.

Central Role Of Il-23 And Il-17 Producing Eosinophils As Immunomodulatory Effector Cells In Acute Pulmonary Aspergillosis And Allergic Asthma, Evelyn V. Santos Guerra, Chrono K. Lee, Charles A. Specht, Bhawna Yadav, Haibin Huang, Ali Akalin, Jun R. Huh, Christian Mueller, Stuart M. Levitz

Christian Mueller

Aspergillus fumigatus causes invasive pulmonary disease in immunocompromised hosts and allergic asthma in atopic individuals. We studied the contribution of lung eosinophils to these fungal diseases. By in vivo intracellular cytokine staining and confocal microscopy, we observed that eosinophils act as local sources of IL-23 and IL-17. Remarkably, mice lacking eosinophils had a >95% reduction in the percentage of lung IL-23p19+ cells as well as markedly reduced IL-23 heterodimer in lung lavage fluid. Eosinophils killed A. fumigatus conidia in vivo. Eosinopenic mice had higher mortality rates, decreased recruitment of inflammatory monocytes, and decreased expansion of lung macrophages after challenge with …

Type I Interferon Induction By Neisseria Gonorrhoeae: Dual Requirement Of Cyclic Gmp-Amp Synthase And Toll-Like Receptor 4, Warrison A. Andrade, Sarika Agarwal, Shunyan Mo, Scott A. Shaffer, Joseph P. Dillard, Tobias Schmidt, Veit Hornung, Katherine A. Fitzgerald, Evelyn A. Kurt-Jones, Douglas T. Golenbock

Katherine A. Fitzgerald

The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2'3'-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I IFN induction. We demonstrate that …

Structural And Molecular Analysis Of A Protective Epitope Of Lyme Disease Antigen Ospa And Antibody Interactions, Shivender Shandilya, Nese Kurt Yilmaz, Ejemel Monir, Andrew Sadowski, William D. Thomas, Mark S. Klempner, Celia A. Schiffer, Yan Wang

Celia A. Schiffer

The murine monoclonal antibody LA-2 recognizes a clinically protective epitope on outer surface protein (OspA) of Borrelia burgdorferi, the causative agent of Lyme disease in North America. Human antibody equivalence to LA-2 is the best serologic correlate of protective antibody responses following OspA vaccination. Understanding the structural and functional basis of the LA-2 protective epitope is important for developing OspA-based vaccines and discovering prophylactic antibodies against Lyme disease. Here, we present a detailed structure-based analysis of the LA-2/OspA interaction interface and identification of residues mediating antibody recognition. Mutations were introduced into both OspA and LA-2 based on computational predictions on …

Genomic Insights Into The Ixodes Scapularis Tick Vector Of Lyme Disease, Monika Gulia-Nuss,, Daniel R. Caffrey, Neal S. Silverman, Adam R. Wespiser, Catherine A. Hill

Neal Silverman

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing approximately 57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick-host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host 'questing', prolonged feeding, …

Blastomyces: Why Be Dimorphic?, Dennis J. Baumgardner

Dennis J. Baumgardner, MD

In introducing the infectious disease focus for this edition of the Journal of Patient-Centered Research and Reviews, the author describes the unsolved mysteries surrounding the dimorphic fungus Blastomyces and the related pathogenesis of pulmonary blastomycosis.

Clinical Approach To Nonresponsive Pneumonia In Adults Diagnosed By A Primary Care Clinician: A Retrospective Study, Kiley B. Vander Wyst, Jessica J. F. Kram, Dennis J. Baumgardner

Dennis J. Baumgardner, MD

Purpose

Community-acquired pneumonia (CAP) is commonly diagnosed in the primary care setting. Management of nonresponsive pneumonia (NRP), i.e. failure to respond to CAP treatment, is not clearly understood. The purpose of this study was to describe the initial work-up and treatment of CAP in the ambulatory primary care setting and to determine relative proportion of, diagnostic approach to and treatment of NRP.

Methods

We retrospectively studied adult patients diagnosed with CAP within our large, integrated health care system from October 2006 through July 2013. Cases were defined as patients with CAP who worsened after 4 days, or did not improve …

Geodemographic Features Of Human Blastomycosis In Eastern Wisconsin, Megan E. Huber, Dennis J. Baumgardner, Jessica J. F. Kram, Melissa A. Lemke

Dennis J. Baumgardner, MD

Purpose

Blastomycosis is an endemic fungal infection. In rural northern Wisconsin, blastomycosis cases are associated with certain environmental features including close proximity to waterways. Other studies have associated blastomycosis with particular soil chemicals. However, blastomycosis also occurs in urban and suburban regions. We explored the geodemographic associations of blastomycosis cases in the more urban/suburban landscape of eastern Wisconsin.

Methods

We conducted a retrospective study of 193 laboratory-identified blastomycosis cases in a single eastern Wisconsin health system, 2007–2015. Controls were 250 randomly selected cases of community-diagnosed pneumonia from a similar time period. Geographic features of home addresses were explored using Google …

Disease-Causing Fungi In Homes And Yards In The Midwestern United States, Dennis J. Baumgardner

Dennis J. Baumgardner, MD

A number of fungal pathogens that may result in a variety of human diseases are found in residential homes and yards. The growth of these microscopic fungi is often favored by particular characteristics of the dwelling and nearby outdoor environment. Evolved virulence factors or increased ability of specific fungi to grow in diverse, and sometimes harsh, microenvironments presented by the domestic environment may promote growth and pathogenesis. Infection may occur by inhalation or direct inoculation and include endemic fungi in addition to opportunistic or emerging species. Systemic or locally aggressive fungal infections are particularly likely and may be life-threatening in …

Geographic Distribution Of Maternal Group B Streptococcus Colonization And Infant Death During Birth Hospitalization: Eastern Wisconsin, Jessica J. F. Kram, Dennis J. Baumgardner, Kiley B. Vander Wyst, Melissa A. Lemke

Dennis J. Baumgardner, MD

Purpose

Maternal group B Streptococcus (GBS) can be transmitted from a colonized mother to newborn during vaginal delivery and may or may not contribute to infant death. This study aimed to explore the geographic distribution and risk factors of maternal GBS colonization and infant death during birth hospitalization.

Methods

We retrospectively studied mothers with live birth(s) in a large eastern Wisconsin hospital system from 2007 through 2013. Associations between maternal and neonatal variables, GBS colonization and infant death were examined using chi-squared, Mann-Whitney U and t-tests. Multivariable logistic regression models also were developed.

Results

Study population (N = 99,305) had …

A Comparison Of Pharmacist Travel-Health Specialists' Versus Primary Care Providers' Recommendations For Travel-Related Medications, Vaccinations, And Patient Compliance In A College Health Setting, Melissa J. Durham, Jeffery A. Goad, Lawrence S. Neinstein, Mimi Lou

Jeff Goad

Background. Pretravel medication and vaccination recommendations and receipt were compared between primary care providers (PCPs) without special training and clinical pharmacists specializing in pretravel health. Methods. A retrospective chart review of patients seen for pretravel health services in a pharmacist-run travel clinic (PTC) compared to PCPs at a University Student Health Center. Vaccine/medication recommendations were assessed for consistency with national/international guidelines. Medical/pharmacy records were queried to determine the receipt of medications/vaccinations. Results. The PTC recommended antibiotics for travelers' diarrhea were given more often when indicated (96% vs 50%, p < 0.0001), and patients seen in the PTC received their medications more …

Large Interdomain Rearrangement Triggered By Suppression Of Micro- To Millisecond Dynamics In Bacterial ​Enzyme I, Vincenzo Venditti, Vitali Tugarinov, Charles D. Schwieters, Alexander Grishaev, G. Marius Clore

Vincenzo Venditti

Enzyme I (EI), the first component of the bacterial phosphotransfer signal transduction system, undergoes one of the largest substrate-induced interdomain rearrangements documented to date. Here we characterize the perturbations generated by two small molecules, the natural substrate phosphoenolpyruvate and the inhibitor a-ketoglutarate, on the structure and dynamics of EI using NMR, small-angle X-ray scattering and biochemical techniques. The results indicate unambiguously that the open-to-closed conformational switch of EI is triggered by complete suppression of micro- to millisecond dynamics within the C-terminal domain of EI. Indeed, we show that a ligand-induced transition from a dynamic to a more rigid conformational state …

Malaria-Induced Nlrp12/Nlrp3-Dependent Caspase-1 Activation Mediates Inflammation And Hypersensitivity To Bacterial Superinfection, Marco A. Ataide, Warrison A. Andrade, Dario S. Zamboni, Donghai Wang, Maria Do Carmo Souza, Bernardo S. Franklin, Samir Elian, Flaviano S. Martins, Dhelio Pereira, George W. Reed, Katherine A. Fitzgerald, Douglas T. Golenbock, Ricardo T. Gazzinelli

Katherine A. Fitzgerald

Cyclic paroxysm and high fever are hallmarks of malaria and are associated with high levels of pyrogenic cytokines, including IL-1beta. In this report, we describe a signature for the expression of inflammasome-related genes and caspase-1 activation in malaria. Indeed, when we infected mice, Plasmodium infection was sufficient to promote MyD88-mediated caspase-1 activation, dependent on IFN-gamma-priming and the expression of inflammasome components ASC, P2X7R, NLRP3 and/or NLRP12. Pro-IL-1beta expression required a second stimulation with LPS and was also dependent on IFN-gamma-priming and functional TNFR1. As a consequence of Plasmodium-induced caspase-1 activation, mice produced extremely high levels of IL-1beta upon a second …

A Nmr Experiment For Simultaneous Correlations Of Valine And Leucine/Isoleucine Methyls With Carbonyl Chemical Shifts In Proteins, Vitali Tugarinov, Vincenzo Venditti, G. Marius Clore

Vincenzo Venditti

A methyl-detected ‘out-and-back’ NMR experiment for obtaining simultaneous correlations of methyl resonances of valine and isoleucine/leucine residues with backbone carbonyl chemical shifts, SIM-HMCM(CGCBCA)CO, is described. The developed pulse-scheme serves the purpose of convenience in recording a single data set for all Ileδ1, Leuδ and Valγ (ILV) methyl positions instead of acquiring two separate spectra selective for valine or leucine/isoleucine residues. The SIM-HMCM(CGCBCA)CO experiment can be used for ILV methyl assignments in moderately sized protein systems (up to ~100 kDa) where the backbone chemical shifts of 13Cα, 13Cβ and 13CO are known from prior NMR studies and where some losses in …

Treating Methicillin-Resistant Staphylococcus Aureus With The Drug Vancomycin In A Home Infusion Therapy Setting, Joshua L. Webb, Alberto Coustasse, Dennis Emmett

Alberto Coustasse, DrPH, MD, MBA, MPH

The basic purpose of this paper is to examine the effects the home infusion therapy has on the cost, duration of, and effectiveness of treatment between those individuals under 60 and those 60 and over. The results show that those 60 and over had a slightly higher cost/day. The older age group had slightly smaller treatment duration, then the younger group. The number of adverse effects was small. The results suggest that home infusion therapy appears to be a viable alternative to hospitalization.

Identification Of A Human Monoclonal Antibody To Replace Equine Diphtheria Anti-Toxin For The Treatment Of Diphtheria, Leila M. Sevigny, Brian J. Booth, Kirk J. Rowley, Brett A. Leav, Peter S. Cheslock, Kerry A. Garrity, Susan Sloan, Gregory J. Babcock, William D. Thomas, Mark Klempner, Yang Wang

William D Thomas Jr

Diphtheria anti-toxin (DAT) has been used to treat Corynebacterium diphtheriae infection for over one hundred years. While the global incidence of diphtheria has declined in the 20th century, the disease remains endemic in many parts of the world and significant outbreaks still occur. Diphtheria anti-toxin is an equine polyclonal antibody with considerable side effects that is in critically short supply globally. A safer, more readily available alternative to DAT would be desirable. In the current study, we cloned human monoclonal antibodies (HuMabs) directly from antibody secreting cells of human volunteers immunized with Td vaccine. We isolated a diverse panel of …

Structural Basis For Enzyme I Inhibition By Α-Ketoglutarate, Vincenzo Venditti, Rodolfo Ghirlando, G. Marius Clore

Vincenzo Venditti

Creating new bacterial strains in which carbon and nitrogen metabolism are uncoupled is potentially very useful for optimizing yields of microbial produced chemicals from renewable carbon sources. However, the mechanisms that balance carbon and nitrogen consumption in bacteria are poorly understood. Recently, α-ketoglutarate (αKG), the carbon substrate for ammonia assimilation, has been observed to inhibit Escherichia coli enzyme I (EI), the first component of the bacterial phosphotransferase system (PTS), thereby providing a direct biochemical link between central carbon and nitrogen metabolism. Here we investigate the EI-αKG interaction by NMR and enzymatic assays. We show that αKG binds with a KD …

Structure, Dynamics And Biophysics Of The Cytoplasmic Protein–Protein Complexes Of The Bacterial Phosphoenolpyruvate: Sugar Phosphotransferase System, Vincenzo Venditti

Vincenzo Venditti

The bacterial phosphotransferase system (PTS) couples phosphoryl transfer, via a series of bimolecular protein–protein interactions, to sugar transport across the membrane. The multitude of complexes in the PTS provides a paradigm for studying protein interactions, and for understanding how the same binding surface can specifically recognize a diverse array of targets. Fifteen years of work aimed at solving the solution structures of all soluble protein–protein complexes of the PTS has served as a test bed for developing NMR and integrated hybrid approaches to study larger complexes in solution and to probe transient, spectroscopically invisible states, including encounter complexes. We review …

The Use Of A Ditopic Gd(Iii) Paramagnetic Probe For Investigating Α-Bungarotoxin Surface Accessibility, Andrea Bernini, Ottavia Spiga, Vincenzo Venditti, Filippo Prischi, Mauro Botta, Gianluca Croce, Angela Pui-Ling Tong, Wing-Talk Wong, Neri Niccolai

Vincenzo Venditti

Protein surface accessibility is a critical parameter which drives all intermolecular interaction processes. In this respect a big deal of information has been derived by analyzing paramagnetic perturbation profiles obtained from NMR protein spectra, particularly in the case that the effects due to different soluble paramagnets can be compared. Here Gd2L7, a neutral ditopic paramagnetic NMR probe, has been characterized in terms of structure and relaxivity and its paramagnetic perturbations on α-bungarotoxin CαH signals in 1H–13C HSQC (heteronuclear single quantum coherence) spectra have been analyzed. Then, these signal attenuations have been compared with the ones previously obtained in the presence …

An Efficient Protocol For Incorporation Of An Unnatural Amino Acid In Perdeuterated Recombinant Proteins Using Glucose-Based Media, Vincenzo Venditti, Nicolas L. Fawzi, G. Marius Clore

Vincenzo Venditti

The in vivo incorporation of unnatural amino acids into proteins is a well-established technique requiring an orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for the unnatural amino acid that is incorporated at a position encoded by a TAG amber codon. Although this technology provides unique opportunities to engineer protein structures, poor protein yields are usually obtained in deuterated media, hampering its application in the protein NMR field. Here, we describe a novel protocol for incorporating unnatural amino acids into fully deuterated proteins using glucose-based media (which are relevant to the production, for example, of amino acid-specific methyl-labeled proteins used in the study …

Conformational Selection And Substrate Binding Regulate The Monomer/Dimer Equilibrium Of The C-Terminal Domain Of Escherichia Coli Enzyme I, Vincenzo Venditti, G. Marius Clore

Vincenzo Venditti

The bacterial phosphotransferase system (PTS) is a signal transduction pathway that couples phosphoryl transfer to active sugar transport across the cell membrane. The PTS is initiated by the binding of phosphoenolpyruvate (PEP) to the C-terminal domain (EIC) of enzyme I (EI), a highly conserved protein that is common to all sugar branches of the PTS. EIC exists in a dynamic monomer/dimer equilibrium that is modulated by ligand binding and is thought to regulate the overall PTS. Isolation of EIC has proven challenging, and conformational dynamics within the EIC domain during the catalytic cycle are still largely unknown. Here, we present …

Automated Sequence- And Stereo-Specific Assignment Of Methyl-Labeled Proteins By Paramagnetic Relaxation And Methyl–Methyl Nuclear Overhauser Enhancement Spectroscopy, Vincenzo Venditti, Nicolas L. Fawzi, G. Marius Clore

Vincenzo Venditti

Methyl-transverse relaxation optimized spectroscopy is rapidly becoming the preferred NMR technique for probing structure and dynamics of very large proteins up to ~1 MDa in molecular size. Data interpretation, however, necessitates assignment of methyl groups which still presents a very challenging and time-consuming process. Here we demonstrate that, in combination with a known 3D structure, paramagnetic relaxation enhancement (PRE), induced by nitroxide spin-labels incorporated at only a few surface-exposed engineered cysteines, provides fast, straightforward and robust access to methyl group resonance assignments, including stereoassignments for the methyl groups of leucine and valine. Neither prior assignments, including backbone assignments, for the …

A Structurally Driven Analysis Of Thiol Reactivity In Mammalian Albumins, Ottavia Spiga, Domenico Summa, Simone Cirri, Andrea Bernini, Vincenzo Venditti, Matteo De Chiara, Raffaella Priora, Simona Frosail, Antonios Margaritis, Danila Di Giuseppe, Paolo Di Simplicio, Neri Niccolai

Vincenzo Venditti

Understanding the structural basis of protein redox activity is still an open question. Hence, by using a structural genomics approach, different albumins have been chosen to correlate protein structural features with the corresponding reaction rates of thiol exchange between albumin and disulfide DTNB. Predicted structures of rat, porcine, and bovine albumins have been compared with the experimentally derived human albumin. High structural similarity among these four albumins can be observed, in spite of their markedly different reactivity with DTNB. Sequence alignments offered preliminary hints on the contributions of sequence-specific local environments modulating albumin reactivity. Molecular dynamics simulations performed on experimental …