DOCSLIB.ORG

Discovery of Novel Antibiotics Via Streptomyces Sporulation by Scott

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Discovery of Novel Antibiotics Via Streptomyces Sporulation by Scott Discovery of novel antibiotics via Streptomyces sporulation by Scott McAuley A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Graduate Department of Biochemistry University of Toronto c Copyright 2019 by Scott McAuley Abstract Discovery of novel antibiotics via Streptomyces sporulation Scott McAuley Doctor of Philosophy Graduate Department of Biochemistry University of Toronto 2019 Streptomyces are filamentous bacteria known for producing a wide range of bioactive molecules. In addition to being nature's chemists they have a unique multicellular life- cycle that ends with the sporulation of aerial hyphae. I used this unique Streptomyces development cycle, specifically sporulation, as a screening platform to discover novel bi- ologically active molecules and characterized their mechanisms of action. Min-1 inhibits the growth of a range of Gram-positive bacteria, is active against the cell envelope, and induces a short cell phenotype in B. subtilis. Another molecule, EN-7, inhibits bacterial gyrase and is active against extensively resistant Staphylococcus aureus in addition to other Gram-positive pathogens. In addition to investigating these specific molecules, I developed a high-throughput screen to identify molecules that disrupt the Gram-positive bacterial membrane and found that Streptomyces venezuelae sporulation is highly sensi- tive to multiple forms of DNA damage. ii Contents 1 Introduction 1 1.1 The challenges of antibiotic discovery and development . 1 1.2 Identifying novel antimicrobials and their mechanism of action . 3 1.2.1 Identifying bioactive molecules through growth inhibition . 4 1.2.2 Identifying mechanism of action through reporter screens and assays 7 1.2.3 Target-based screening . 13 1.2.4 Novel screening approaches . 14 1.2.5 Conclusions . 16 1.3 Small molecule impact on bacterial morphology . 17 1.3.1 Activators of the SOS response disrupt the cell cycle . 18 1.3.2 Cell envelope determines cell shape . 21 1.3.3 Direct disruption of FtsZ disrupts the cell cycle . 23 1.3.4 Nutrient availability impacts both growth and the cell cycle . 25 1.3.5 Cytological profiling identifies antibiotic mechanisms of action . 27 1.3.6 Conclusion . 27 1.4 Thesis objectives and outline . 28 2 Membrane activity profiling of small molecule B. subtilis growth in- hibitors utilizing novel duel-dye fluorescence assay 29 2.1 Abstract . 29 2.2 Introduction . 30 2.3 Results and Discussion . 32 2.3.1 High-throughput assay for determining impact on membrane po- tential and permeability . 32 2.3.2 Screen for biologically active small molecules against B. subtilis . 34 2.3.3 Membrane disruption by biologically active small molecules . 36 2.4 Conclusion . 40 iii 3 A chemical inhibitor of cell growth reduces cell size in Bacillus subtilis 46 3.1 Abstract . 46 3.2 Introduction . 47 3.3 Results and Discussion . 48 3.3.1 Min-1 inhibits Streptomyces sporulation at sub-inhibitory concen- trations . 48 3.3.2 Min-1 inhibits growth of Gram-positive bacteria and reduces cell length of B. subtilis .......................... 49 3.3.3 Structural analogs of Min-1 have altered effects on growth rate and cell length . 51 3.3.4 Min-1 disrupts coordination between growth and FtsZ ring assembly 55 3.3.5 Min-1 targets the cell envelope . 56 3.3.6 Min-1 is a novel inhibitor of bacterial growth . 60 4 Discovery of a novel DNA gyrase-targeting antibiotic through the chem- ical perturbation of Streptomyces venezuelae sporulation 62 4.1 Abstract . 62 4.2 Introduction . 63 4.3 Results . 64 4.3.1 The Streptomyces venezuelae sporulation program is sensitive to DNA damage . 64 4.3.2 Novel small molecule sporulation inhibitors . 66 4.3.3 EN-7 targets DNA gyrase . 68 4.4 Discussion . 75 5 Concluding Remarks 79 5.1 Thesis Summary . 79 5.2 Future Directions . 80 5.2.1 Investigating mechanism of Streptomyces sporulation inhibition via DNA damage . 80 5.2.2 Additional approaches for elucidating Min-1's target and mecha- nism of action . 80 5.2.3 Identify mechanism of gyrase inhibition for EN-7 . 81 5.2.4 Creating high-thoughput method of screening Streptomyces sporu- lation inhibition . 81 5.2.5 Additional small molecule screens against bacterial development . 81 5.3 Conclusion . 82 iv 6 Materials and Methods 83 6.1 General Experimental Procedures . 83 6.1.1 Strains and plasmids . 83 6.2 Growth inhibition assays . 83 6.2.1 Broth dilution assay . 83 6.2.2 Streptomyces sporulation inhibition . 83 6.2.3 Superficial S. aureus skin infection model . 85 6.3 PAINs assays . 85 6.3.1 Duel-dye membrane disruption screen . 85 6.3.2 Dynamic Light Scattering . 85 6.4 Miscroscopy Methods . 86 6.4.1 Scanning electron miscroscopy . 86 6.4.2 B. subtilis cell length measurement and FtsZ immunofluorescence labeling . 86 6.5 Reporter assays . 87 6.6 Isolation and characterization of resistant mutants . 87 6.6.1 Resistant mutant generation . 87 6.6.2 Sequencing resistant mutants . 87 6.6.3 S. aureus allelic exchange . 88 6.7 Gyrase inhibition . 88 6.7.1 E. coli gyrase supercoiling . 88 6.7.2 S. aureus gyrase supercoiling . 89 6.7.3 E. coli topoisomerase IV decatenation . 89 6.7.4 S.aureus topoisomerase IV decatenation . 89 6.7.5 S.aureus gyrase cleavage . 89 7 Appendix 1: A chemical inhibitor of cell growth reduces cell size in Bacillus subtilis 90 7.1 Results and Discussion . 90 7.1.1 Min-1 does not inhibit B. subtilis sporulation . 90 7.1.2 Min-1 activates B. subtilis PywaC-lux reporter . 91 7.1.3 Unable to generate Min-1 resistant mutants . 91 7.1.4 Min-1 potentiates some known antibiotics . 92 7.1.5 Identifying sensitive strains using a B. subtilis knockdown library 93 7.1.6 Impact of Min-1 on HEK293 viability . 96 v 8 Appendix 2: Discovery of a novel DNA gyrase-targeting antibiotic through the chemical perturbation of Streptomyces venezuelae sporu- lation 98 8.1 Results and Discussion . 98 8.1.1 Growth inhibition and reporter activation of S. venezuelae sporu- lation screen hits . 98 8.1.2 Aggregation activity of S. venezuelae sporulation screen hits . 101 8.1.3 Gyrase S. aureus antisense strains show resistance to EN-7 . 101 8.1.4 EN-7 does not reduce S. aureus bacterial load in a skin mouse infection model . 104 Bibliography 106 vi List of Tables 1.1 Reporter strains used to identify antibiotic MOA . 10 1.2 Cell morphologies induced by cell wall inhibiting antibiotics . 24 3.1 Minimum inhibitory concentration of Min-1 . 50 4.1 Table of gyrase mutations found in EN-7 resistant mutants . 68 6.1 Table of strains used in studies . 84 7.1 Impact of Min-1 on activity of known antibiotics . 94 7.2 B. subtilis CRISPRi hits on xylose induction with Min-1 treatment . 96 8.1 Growth inhibition of S. venezuelae sporulation screen hits . 100 8.2 Growth inhibition of S. venezuelae sporulation screen hits . 102 vii List of Figures 1.1 Simplified screening processes for discovering new antibiotics and uncov- ering their mechanism of action . 4 1.2 Examples of bioactive molecules containing PAIN substructures . 5 1.3 Whole-cell reporter assays for determining MOA . 9 1.4 Chemical-genetic assays for determining MOA . 12 1.5 Streptomyces lifecycle . 16 1.6 Small molecules activate the SOS response and disrupts the cell cycle . 19 2.1 Chemical and optical properties of TO-PRO-3 iodide and DiOC2(3) . 33 2.2 Effect of known nisin, CCCP, and vancomycin on TO-PRO-3 iodide and DiOC2(3) fluorescence . 35 2.3 Screen of bioactive synthetic molecules for membrane activity . 37 2.4 Membrane activity screen summary . 39 2.5 Concentration dependent impact of bioactive molecules on TO-PRO-3 io- dide and DiOC2(3) fluorescence . 40 2.6 Membrane permeability hits . 42 2.7 Membrane potential hits . 43 2.8 Membrane potential hits, cont. 44 2.9 Calculated logP values for bioactive compound library . 45 3.1 Effect of Min-1 on S. venezuelae development . 49 3.2 Cell length and growth rate effects of Min-1 on B. subtilis . 52 3.3 Structure and activity of Min-1 analogs against B. subtilis and S. aureus 53 3.4 Effect of Min-1 analogs on B. subtilis growth and cell length . 54 3.5 Min-1 disrupts coordination between growth and FtsZ ring assembly in- dependent of known cell size mechanisms . 57 3.6 Min-1 targets the cell envelope . 59 3.7 Impact of supplemental magnesium on Min-1 activity . 60 viii 4.1 Streptomyces venezuelae sporulation is sensitive to DNA damage . 65 4.2 Chemical structures and induced S. venezuelae phenotypes . 66 4.3 Identification of EN-7 as an inhibitor of S. venezuale and Gram-positive pathogens . 67 4.4 EN-7 inhibits growth of extensively resistant S. aureus . 69 4.5 Allelic Exchange of EN-7 resistance mutations into S. aureus . 71 4.6 in-vitro inhibition of S. aureus gyrase by EN-7 . 72 4.7 Cross-resistance of EN-7 resistant strains with other gyrase inhibitors . 73 4.8 Chemical structures of EN-7 and other investigational gyrase inhibitors . 74 4.9 Analysis of EN-7 resistance gyrase mutations . 76 7.1 Min-1 does not disrupt B. subtilis sporulation . 91 7.2 Min-1 activates B. subtilis PywaC-lux reporter strain . 92 7.3 Min-1 potentiates known antibiotics . 93 7.4 Impact of Min-1 on growth of a B. subtilis CRISPRi essential knock-down library . ..
Load more

Recommended publications
  • Annual Conference Abstracts
    ANNUAL CONFERENCE 14-17 April 2014 Arena and Convention Centre, Liverpool ABSTRACTS SGM ANNUAL CONFERENCE APRIL 2014 ABSTRACTS (LI00Mo1210) – SGM Prize Medal Lecture (LI00Tu1210) – Marjory Stephenson Climate Change, Oceans, and Infectious Disease Prize Lecture Dr. Rita R. Colwell Understanding the basis of antibiotic resistance University of Maryland, College Park, MD, USA as a platform for early drug discovery During the mid-1980s, satellite sensors were developed to monitor Laura JV Piddock land and oceans for purposes of understanding climate, weather, School of Immunity & Infection and Institute of Microbiology and and vegetation distribution and seasonal variations. Subsequently Infection, University of Birmingham, UK inter-relationships of the environment and infectious diseases Antibiotic resistant bacteria are one of the greatest threats to human were investigated, both qualitatively and quantitatively, with health. Resistance can be mediated by numerous mechanisms documentation of the seasonality of diseases, notably malaria including mutations conferring changes to the genes encoding the and cholera by epidemiologists. The new research revealed a very target proteins as well as RND efflux pumps, which confer innate close interaction of the environment and many other infectious multi-drug resistance (MDR) to bacteria. The production of efflux diseases. With satellite sensors, these relationships were pumps can be increased, usually due to mutations in regulatory quantified and comparatively analyzed. More recent studies of genes, and this confers resistance to antibiotics that are often used epidemic diseases have provided models, both retrospective and to treat infections by Gram negative bacteria. RND MDR efflux prospective, for understanding and predicting disease epidemics, systems not only confer antibiotic resistance, but altered expression notably vector borne diseases.
    [Show full text]
  • Overcoming Fluoroquinolone Resistance: Mechanistic Basis of Non- Quinolone Antibacterials Targeting Type Ii Topoisomerases
    OVERCOMING FLUOROQUINOLONE RESISTANCE: MECHANISTIC BASIS OF NON- QUINOLONE ANTIBACTERIALS TARGETING TYPE II TOPOISOMERASES By Elizabeth Grace Gibson Dissertation Submitted to the Faculty of the Graduate School of Vanderbilt University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Pharmacology May 10, 2019 Nashville, Tennessee Approved: Neil Osheroff, Ph.D. Joey Barnett, Ph.D. Wendell S. Akers, Pharm.D., Ph.D. Sean Davies, Ph.D. Benjamin Spiller, Ph.D. Timothy R. Sterling, M.D. DEDICATION To all my family and church family who have supported and encouraged me over all my years in school. To Him who I put all my trust. Commit your way to the Lord, trust also in Him and He shall bring it to pass. Psalm 37:5 ii ACKNOWLEDGEMENTS I want to first thank my Ph.D. advisor, Dr. Neil Osheroff, for allowing me to work in his laboratory. Thank you for all your support and encouragement and just being an overall great mentor. You really know how to bring us up when we need it or give us an ego check when we get a little high and mighty when things are going well. I appreciate your supportiveness to careers outside academia. I also appreciate that you always have our best interest at heart. To Dr. Joe Deweese, my first research mentor and the one who instilled the love of topoisomerase research. Without your guidance I would not be where I am today. Thank you for introducing me to Neil and his laboratory and helping with the transition from research in your lab to his.
    [Show full text]
  • Infant Antibiotic Exposure Search EMBASE 1. Exp Antibiotic Agent/ 2
    Infant Antibiotic Exposure Search EMBASE 1. exp antibiotic agent/ 2. (Acedapsone or Alamethicin or Amdinocillin or Amdinocillin Pivoxil or Amikacin or Aminosalicylic Acid or Amoxicillin or Amoxicillin-Potassium Clavulanate Combination or Amphotericin B or Ampicillin or Anisomycin or Antimycin A or Arsphenamine or Aurodox or Azithromycin or Azlocillin or Aztreonam or Bacitracin or Bacteriocins or Bambermycins or beta-Lactams or Bongkrekic Acid or Brefeldin A or Butirosin Sulfate or Calcimycin or Candicidin or Capreomycin or Carbenicillin or Carfecillin or Cefaclor or Cefadroxil or Cefamandole or Cefatrizine or Cefazolin or Cefixime or Cefmenoxime or Cefmetazole or Cefonicid or Cefoperazone or Cefotaxime or Cefotetan or Cefotiam or Cefoxitin or Cefsulodin or Ceftazidime or Ceftizoxime or Ceftriaxone or Cefuroxime or Cephacetrile or Cephalexin or Cephaloglycin or Cephaloridine or Cephalosporins or Cephalothin or Cephamycins or Cephapirin or Cephradine or Chloramphenicol or Chlortetracycline or Ciprofloxacin or Citrinin or Clarithromycin or Clavulanic Acid or Clavulanic Acids or clindamycin or Clofazimine or Cloxacillin or Colistin or Cyclacillin or Cycloserine or Dactinomycin or Dapsone or Daptomycin or Demeclocycline or Diarylquinolines or Dibekacin or Dicloxacillin or Dihydrostreptomycin Sulfate or Diketopiperazines or Distamycins or Doxycycline or Echinomycin or Edeine or Enoxacin or Enviomycin or Erythromycin or Erythromycin Estolate or Erythromycin Ethylsuccinate or Ethambutol or Ethionamide or Filipin or Floxacillin or Fluoroquinolones
    [Show full text]
  • B-Lactams: Chemical Structure, Mode of Action and Mechanisms of Resistance
    b-Lactams: chemical structure, mode of action and mechanisms of resistance Ru´ben Fernandes, Paula Amador and Cristina Prudeˆncio This synopsis summarizes the key chemical and bacteriological characteristics of b-lactams, penicillins, cephalosporins, carbanpenems, monobactams and others. Particular notice is given to first-generation to fifth-generation cephalosporins. This review also summarizes the main resistance mechanism to antibiotics, focusing particular attention to those conferring resistance to broad-spectrum cephalosporins by means of production of emerging cephalosporinases (extended-spectrum b-lactamases and AmpC b-lactamases), target alteration (penicillin-binding proteins from methicillin-resistant Staphylococcus aureus) and membrane transporters that pump b-lactams out of the bacterial cell. Keywords: b-lactams, chemical structure, mechanisms of resistance, mode of action Historical perspective Alexander Fleming first noticed the antibacterial nature of penicillin in 1928. When working with Antimicrobials must be understood as any kind of agent another bacteriological problem, Fleming observed with inhibitory or killing properties to a microorganism. a contaminated culture of Staphylococcus aureus with Antibiotic is a more restrictive term, which implies the the mold Penicillium notatum. Fleming remarkably saw natural source of the antimicrobial agent. Similarly, under- the potential of this unfortunate event. He dis- lying the term chemotherapeutic is the artificial origin of continued the work that he was dealing with and was an antimicrobial agent by chemical synthesis [1]. Initially, able to describe the compound around the mold antibiotics were considered as small molecular weight and isolates it. He named it penicillin and published organic molecules or metabolites used in response of his findings along with some applications of penicillin some microorganisms against others that inhabit the same [4].
    [Show full text]
  • Streptomyces Cytochrome P450 Enzymes and Their Roles in the Biosynthesis of Macrolide Therapeutic Agents
    Review Biomol Ther 27(2), 127-133 (2019) Streptomyces Cytochrome P450 Enzymes and Their Roles in the Biosynthesis of Macrolide Therapeutic Agents Myung-A Cho, Songhee Han, Young-Ran Lim, Vitchan Kim, Harim Kim and Donghak Kim,* Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea Abstract The study of the genus Streptomyces is of particular interest because it produces a wide array of clinically important bioactive molecules. The genomic sequencing of many Streptomyces species has revealed unusually large numbers of cytochrome P450 genes, which are involved in the biosynthesis of secondary metabolites. Many macrolide biosynthetic pathways are catalyzed by a series of enzymes in gene clusters including polyketide and non-ribosomal peptide synthesis. In general, Streptomyces P450 enzymes accelerate the final, post-polyketide synthesis steps to enhance the structural architecture of macrolide chemistry. In this review, we discuss the major Streptomyces P450 enzymes research focused on the biosynthetic processing of macrolide therapeutic agents, with an emphasis on their biochemical mechanisms and structural insights. Key Words: Streptomyces, P450, CYP, Biosynthesis, Macrolide, Secondary metabolite INTRODUCTION isms became important to human health with the discovery of penicillin in 1928 by Fleming, and the discovery of the anti- The phylum actinobacteria is one of the major lineages cur- tuberculosis agent streptomycin from Streptomyces griseus rently recognized within bacteria (Ventura et al., 2007). Acti- in 1944 by Waksman (Ikeda, 2017). More recently, the 2015 nobacteria are widely distributed in terrestrial, especially soil, Nobel prize in Physiology or Medicine was awarded to Omura and aquatic ecosystems (McCarthy and Williams, 1992; Stach and Campbell for their contributions to the discovery of the and Bull, 2005).
    [Show full text]
  • Antibiotic Use Guidelines for Companion Animal Practice (2Nd Edition) Iii
    ii Antibiotic Use Guidelines for Companion Animal Practice (2nd edition) iii Antibiotic Use Guidelines for Companion Animal Practice, 2nd edition Publisher: Companion Animal Group, Danish Veterinary Association, Peter Bangs Vej 30, 2000 Frederiksberg Authors of the guidelines: Lisbeth Rem Jessen (University of Copenhagen) Peter Damborg (University of Copenhagen) Anette Spohr (Evidensia Faxe Animal Hospital) Sandra Goericke-Pesch (University of Veterinary Medicine, Hannover) Rebecca Langhorn (University of Copenhagen) Geoffrey Houser (University of Copenhagen) Jakob Willesen (University of Copenhagen) Mette Schjærff (University of Copenhagen) Thomas Eriksen (University of Copenhagen) Tina Møller Sørensen (University of Copenhagen) Vibeke Frøkjær Jensen (DTU-VET) Flemming Obling (Greve) Luca Guardabassi (University of Copenhagen) Reproduction of extracts from these guidelines is only permitted in accordance with the agreement between the Ministry of Education and Copy-Dan. Danish copyright law restricts all other use without written permission of the publisher. Exception is granted for short excerpts for review purposes. iv Foreword The first edition of the Antibiotic Use Guidelines for Companion Animal Practice was published in autumn of 2012. The aim of the guidelines was to prevent increased antibiotic resistance. A questionnaire circulated to Danish veterinarians in 2015 (Jessen et al., DVT 10, 2016) indicated that the guidelines were well received, and particularly that active users had followed the recommendations. Despite a positive reception and the results of this survey, the actual quantity of antibiotics used is probably a better indicator of the effect of the first guidelines. Chapter two of these updated guidelines therefore details the pattern of developments in antibiotic use, as reported in DANMAP 2016 (www.danmap.org).
    [Show full text]
  • Download (12Mb)
    A Thesis Submitted for the Degree of PhD at the University of Warwick Permanent WRAP URL: http://wrap.warwick.ac.uk/110352 Copyright and reuse: This thesis is made available online and is protected by original copyright. Please scroll down to view the document itself. Please refer to the repository record for this item for information to help you to cite it. Our policy information is available from the repository home page. For more information, please contact the WRAP Team at: [email protected] warwick.ac.uk/lib-publications THE BRITISH LIBRARY BRITISH THESIS SERVICE THE DISTRIBUTION OF PHENOTYPIC AND GENOTYPIC CHARACTERS WITHIN STREPTOMYCETES AND THEIR RELATIONSHIP TITLE . TO ANTIBIOTIC PRODUCTION. AUTHOR........ Lesley Phillips, DEGREE.................................................... AWARDING BODY _ TI. .. The University of Warwick, THESIS NUMBER THIS THESIS HAS BEEN MICROFILMED EXACTLY AS RECEIVED The quality of this reproduction is dependent upon the quality of the original thesis submitted for microfilming. Every effort has been made to ensure the highest quality of reproduction. Some pages may have indistinct print, especially if the original papers were poorly produced or if the awarding body sent an inferior copy. If pages are missing, please contact the awarding body which granted the degree. Previously copyrighted materials (journal articles, published texts, etc.) are not filmed. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that Its copyright rests with its author and that no information derived from it may be published without the author's prior written consent. Reproduction of this thesis, other than as permitted under the United Kingdom Copyright Designs and Patents Act 1988, or under specific agreement with the copyright holder, is prohibited.
    [Show full text]
  • AMEG Categorisation of Antibiotics
    12 December 2019 EMA/CVMP/CHMP/682198/2017 Committee for Medicinal Products for Veterinary use (CVMP) Committee for Medicinal Products for Human Use (CHMP) Categorisation of antibiotics in the European Union Answer to the request from the European Commission for updating the scientific advice on the impact on public health and animal health of the use of antibiotics in animals Agreed by the Antimicrobial Advice ad hoc Expert Group (AMEG) 29 October 2018 Adopted by the CVMP for release for consultation 24 January 2019 Adopted by the CHMP for release for consultation 31 January 2019 Start of public consultation 5 February 2019 End of consultation (deadline for comments) 30 April 2019 Agreed by the Antimicrobial Advice ad hoc Expert Group (AMEG) 19 November 2019 Adopted by the CVMP 5 December 2019 Adopted by the CHMP 12 December 2019 Official address Domenico Scarlattilaan 6 ● 1083 HS Amsterdam ● The Netherlands Address for visits and deliveries Refer to www.ema.europa.eu/how-to-find-us Send us a question Go to www.ema.europa.eu/contact Telephone +31 (0)88 781 6000 An agency of the European Union © European Medicines Agency, 2020. Reproduction is authorised provided the source is acknowledged. Categorisation of antibiotics in the European Union Table of Contents 1. Summary assessment and recommendations .......................................... 3 2. Introduction ............................................................................................ 7 2.1. Background ........................................................................................................
    [Show full text]
  • HEDIS®1 Public Comment Overview
    HEDIS®1 Public Comment Overview HEDIS Overview HEDIS is a set of standardized performance measures designed to ensure that purchasers and consumers can reliably compare the performance of health plans. It also serves as a model for emerging systems of performance measurement in other areas of health care delivery. HEDIS is maintained by NCQA, a not-for-profit organization committed to evaluating and publicly reporting on the quality of health plans, ACOs, physicians, and other organizations. The HEDIS measurement set consists of 92 measures across 6 domains of care. Items available for public comment are being considered for HEDIS Measurement Year 2022, which will be published in August 2021. HEDIS Measure Development Process NCQA’s consensus development process involves rigorous review of published guidelines and scientific evidence, as well as feedback from multi-stakeholder advisory panels. The NCQA Committee on Performance Measurement, a diverse panel of independent scientists and representatives from health plans, consumers, federal policymakers, purchasers and clinicians, oversees the evolution of the HEDIS measurement set. Numerous measurement advisory panels provide clinical and technical knowledge required to develop the measures. Additional HEDIS expert panels and the Technical Measurement Advisory Panel provide invaluable assistance by identifying methodological issues and giving feedback on new and existing measures. Synopsis NCQA seeks public feedback on proposed new HEDIS measures, revisions to existing measures and proposed measure retirement. Reviewers are asked to submit comments to NCQA in writing via the Public Comment website by 11:59 p.m. (ET), Thursday, March 11. Submitting Comments Submit all comments via NCQA’s Public Comment website at https://my.ncqa.org/ Note: NCQA does not accept comments via mail, email or fax.
    [Show full text]
  • Conjunctivitis Or Worse?
    Red Eye in Dogs and CatS: Conjunctivitis or Worse? Tracy Revoir, DVM Senior Manager of Veterinary Support, Dechra Veterinary Products It should come as no surprise that conjunctivitis is Common Causes of Conjunctivitis the most common ophthalmic disorder in dogs and cats. But because the clinical signs of conjunctivitis If you do confirm conjunctivitis, the next step is can mimic those of more serious ophthalmic identifying the cause. If both eyes are affected and diseases (glaucoma and uveitis), it’s important to abnormal clinical signs are apparent in other body confirm your diagnosis. systems, think underlying systemic disease. If only one eye is affected, rule out infection, tear film What are important clues to the severity of the deficiencies, an irritant, anatomical abnormality, condition? With conjunctivitis, the inflammation or deeper ocular disease. should be limited to the conjunctiva. Hyperemic conjunctival vessels are superficial, branching, In dogs, conjunctivitis can result from anatomical and bright red. They are movable over the deeper disorders, irritants, infection (usually bacterial), or episcleral vessels and can be blanched with topical atopy. Most bacterial infections are secondary dilute phenylephrine. With glaucoma and uveitis, the conditions, most often to allergies. In cats, herpes- episcleral vessels are engorged; they are dark red, virus and Chlamydophila felis are the most common deep, straight, and immobile and do not blanch with causes of conjunctivitis. Atopy can also be topical dilute phenylephrine. With conjunctivitis, an issue in cats. the Schirmer tear test and intraocular pressures are normal. And the cornea should be clear and no aqueous flare should be present. The pupil and Addressing the Problem pupillary responses are normal and intraocular structures should be visible.
    [Show full text]
  • Gonorrhea, Chlamydia, and Syphilis
    2019 GONORRHEA, CHLAMYDIA, AND SYPHILIS AND CHLAMYDIA, GONORRHEA, Dedication TAG would like to thank the National Coalition of STD Directors for funding and input on the report. THE PIPELINE REPORT Pipeline for Gonorrhea, Chlamydia, and Syphilis By Jeremiah Johnson Introduction The current toolbox for addressing gonorrhea, chlamydia, and syphilis is inadequate. At a time where all three epidemics are dramatically expanding in locations all around the globe, including record-breaking rates of new infections in the United States, stakeholders must make do with old tools, inadequate systems for addressing sexual health, and a sparse research pipeline of new treatment, prevention, and diagnostic options. Lack of investment in sexual health research has left the field with inadequate prevention options, and limited access to infrastructure for testing and treatment have allowed sexually transmitted infections (STIs) to flourish. The consequences of this underinvestment are large: according to the World Health Organization (WHO), in 2012 there were an estimated 357 million new infections (roughly 1 million per day) of the four curable STIs: gonorrhea, chlamydia, syphilis, and trichomoniasis.1 In the United States, the three reportable STIs that are the focus of this report—gonorrhea, chlamydia, and syphilis—are growing at record paces. In 2017, a total of 30,644 cases of primary and secondary (P&S) syphilis—the most infectious stages of the disease—were reported in the United States. Since reaching a historic low in 2000 and 2001, the rate of P&S syphilis has increased almost every year, increasing 10.5% during 2016–2017. Also in 2017, 555,608 cases of gonorrhea were reported to the U.S.
    [Show full text]
  • Antibiotic Discovery
    ANTIBIOTIC DISCOVERY RESISTANCE PROFILING OF MICROBIAL GENOMES TO REVEAL NOVEL ANTIBIOTIC NATURAL PRODUCTS By CHELSEA WALKER, H. BSc. A Thesis Submitted to the School of Graduate Studies in Partial Fulfilment of the Requirements for the Degree Master of Science McMaster University © Copyright by Chelsea Walker, May 2017 McMaster University MASTER OF SCIENCE (2017) Hamilton, Ontario (Biochemistry and Biomedical Sciences) TITLE: Resistance Profiling of Microbial Genomes to Reveal Novel Antibiotic Natural Products. AUTHOR: Chelsea Walker, H. BSc. (McMaster University) SUPERVISOR: Dr. Nathan A. Magarvey. COMMITTEE MEMBERS: Dr. Eric Brown and Dr. Michael G. Surette. NUMBER OF PAGES: xvii, 168 ii Lay Abstract It would be hard to imagine a world where we could no longer use the antibiotics we are routinely being prescribed for common bacterial infections. Currently, we are in an era where this thought could become a reality. Although we have been able to discover antibiotics in the past from soil dwelling microbes, this approach to discovery is being constantly challenged. At the same time, the bacteria are getting smarter in their ways to evade antibiotics, in the form of resistance, or self-protection mechanisms. As such is it essential to devise methods which can predict the potential for resistance to the antibiotics we use early in the discovery and isolation process. By using what we have learned in the past about how bacteria protect themselves for antibiotics, we can to stay one step ahead of them as we continue to search for new sources of antibiotics from bacteria. iii Abstract Microbial natural products have been an invaluable resource for providing clinically relevant therapeutics for almost a century, including most of the commonly used antibiotics that are still in medical use today.
    [Show full text]