DOCSLIB.ORG

Haemophilus Influenzae and Moraxella Catarrhalis Intra- and Interspecies Quorum Signaling

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Haemophilus Influenzae and Moraxella Catarrhalis Intra- and Interspecies Quorum Signaling HAEMOPHILUS INFLUENZAE AND MORAXELLA CATARRHALIS INTRA- AND INTERSPECIES QUORUM SIGNALING BY CHELSIE E. ARMBRUSTER A Dissertation Submitted to the Graduate Faculty of WAKE FOREST UNIVERSITY GRADUATE SCHOOL OF ARTS AND SCIENCES In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY Microbiology and Immunology May 2011 Winston-Salem, North Carolina Approved By: W. Edward Swords, Ph.D., Advisor Gregory Shelness, Ph.D., Chairman Nancy Kock, DVM Ph.D. David Ornelles, Ph.D. Sean Reid, Ph.D. ACKNOWLEDGEMENTS First and foremost, I would like to thank my advisor Dr. W. Edward Swords for his guidance and enthusiasm in my work, for affording me the independence to pursue some of my more crazy ideas concerning this project, and for helping to keep my research focused on publication. The three years I’ve spent in the Swords’ lab have been more productive than I could have ever imagined, and I really appreciate the mentoring I received from Dr. Swords concerning both research and my future career. I would also like to acknowledge the past and present members of the Swords’ lab who contributed to this body of work, including Gayle Foster, Dr. Wenzhou Hong, Dr. Bing Pang, Dr. Kristin Weimer, Rick Juneau, Kyle Murrah, and Antonia Perez. Special thanks to Gayle, Bing, Kristin, and Rick for helping with all of the animal studies; I would not have been able to do it without you. To Rick and Kristin, thank you for being such great labmates, for talking science and helping with experiments, and for the social atmosphere on our side of the lab. I would also like to thank the students of the Department of Microbiology and Immunology in general for their input on my research and for ensuring that I spent time relaxing outside of lab. I would also like to acknowledge my professors from the Rochester Institute of Technology for the excellent training they provided and for their guidance. If not for Dr. Merrill, I would never have switched from photography to biotechnology. I would also like thank Dr. Ferran for taking a chance and introducing me to research during my first quarter at RIT, and would especially like to thank Dr. Evans, Dr. Lawlor, and Dr. Douthwright for their mentoring and for teaching me to always stay in trouble. ii Finally, I would like to thank my family and Brian Learman for their continuous support. To my mom and dad, you always assured me that I could do anything I put my mind to. Thank you for always believing in me, for listening to me babble about research, and for always being there when I needed you most. To Brian, thank you for always listening when I need to talk through an experiment, for supporting me every step of the way, for loving me despite my craziness, and for helping me put things in perspective when needed. I am truly grateful to have you in my life. iii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS…………………………………………………...…………..ii LIST OF FIGURES……………………………………………………………………….v LIST OF TABLES……………………………………………………………………….vii ABBREVIATIONS………………………………………………………………..……viii ABSTRACT………………………………………………………………………..……xii INTRODUCTION……………………………………………………………………..….1 CHAPTER I: LuxS Promotes Biofilm Maturation and Persistence of Nontypeable Haemophilus influenzae In Vivo via Modulation of Lipooligosaccharides on the Bacterial Surface…………………………………………………..………...…....65 Published in Infection and Immunity, September 2009. CHAPTER II: NTHI_0632 Mediates Quorum Signal Uptake in Nontypeable Haemophilus influenzae Strain 86-028NP……........…...105 Submitted to Molecular Microbiology. CHAPTER III: LuxS Expression Promotes Nontypeable Haemophilus influenzae Biofilm Development and Prevents Dispersal………….....148 Submitted to mBio. CHAPTER IV: Indirect Pathogenicity of Haemophilus influenzae and Moraxella catarrhalis in Polymicrobial Otitis Media Occurs via Interspecies Quorum Signaling……………………………182 Published in mBio, July 2010. CONCLUSIONS………………………………………………………………….……213 APPENDIX……………………………………………………………………….……244 REFERENCE LIST…………………………………………………………….………262 CIRRICULUM VITAE………………………………………………………...………302 iv LIST OF FIGURES Page Figure 1. Important factors involved in the pathogenesis of otitis media……...……….10 Figure 2. Eustachian tube anatomy of children versus adults…………………...……...13 Figure 3. Classification of otitis media………...……………………………………….16 Figure 4. Biofilm development……………………………...………………………….21 Figure 5. Production of AI-2 and known structures………………...……...…………..52 Figure 6. Pathways for homocysteine production…………………………...………….56 Figure 7. Diagram of the Lsr AI-2 transport system……………………………...…....50 Figure 8. Microscopic analysis of in vitro biofilm formation in flow chambers….......85 Figure 9. Complementation of luxS with exogenous AI-2……………………..………88 Figure 10. Analysis of LOS composition……………………………………...…..……91 Figure 11. LuxS promotes biofilm formation and persistence in the chinchilla model of otitis media ………...………….…………………………..……....97 Figure 12. Hematoxylin and eosin staining of bullar sections………………....………100 Figure 13. AI-2 accumulates in late-exponential phase cultures of 86-028NP 0632::Cm……………,,,,………………………………….…….111 Figure 14. Mutation of NTHI_0632 limits AI-2 depletion……………………….……114 Figure 15. Increased luxS and NTHI_0632 transcript levels correlate with AI-2 production………...….……….……………………………………….……119 Figure 16. 86-028NP 0632::Cm forms a biofilm under continuous-flow conditions....122 Figure 17. Mutation of NTHI_0632 results in a similar biofilm maturation defect as mutation of luxS……………………………….…………….…………...124 Figure 18. Nontypeable H. influenzae 86-028NP requires NTHI_0632 to respond to exogenous AI-2………………………………….…………………….……127 v Figure 19. Mutation of NTHI_0632 reduces surface-accessible PCho………….…….130 Figure 20. Mutation of NTHI_0632 limits bacterial persistence in vivo……………...135 Figure 21. Generation of an inducible luxS strain and confirmation of induction….....162 Figure 22. Induction of luxS expression increases phosphorylcholine expression…….165 Figure 23. Induction of luxS expression promotes biofilm development in a stationary system……………………………………………………………168 Figure 24. Modulation of luxS expression alters biofilm development and dispersal…171 Figure 25. Transcription of luxS decreases as biofilms approach dispersal………...…174 Figure 26. Continuous luxS expression prevents biofilm dispersal……………………177 Figure 27. H. influenzae and M. catarrhalis form polymicrobial biofilms in vitro…..193 Figure 28. Beta-lactam protection in a polymicrobial biofilm………………….……..196 Figure 29. Polymicrobial biofilm formation protects H. influenzae and M. catarrhalis from antibiotic treatment……………………………...……198 Figure 30. AI-2 promotes M. catarrhalis biofilm development and antibiotic resistance……………………………………………………………...…….202 Figure 31. Polymicrobial infection augments M. catarrhalis persistence in vivo….…206 Supplemental Figure 1. Bioassay for AI-2 production………………….……………..245 Supplemental Figure 2. Infection with NTHI 86-028NP luxS impacts biomass composition in vivo…………………………………….……..247 Supplemental Figure 3. NTHI 86-028NP and NTHI 86-028NP luxS induce NET formation………………………………………….…………..249 Supplemental Figure 4. AI-2 quorum signaling in NTHI biofilm formation and dispersal…………..…………………………………………..251 Supplemental Figure 5. M. catarrhalis O35E requires Hag for increased resistance to clarithromycin in response to DPD…………….………….255 Supplemental Figure 6. H. influenzae and M. catarrhalis form polymicrobial biofilms during experimental OM……………………………257 vi LIST OF TABLES Page Table 1. Examples of non-pathogenic and potentially pathogenic bacteria that frequently inhabit the nasopharynx………………..….………………...…...….3 Table 2. Polymicrobial human infections……………………...…………………...…..27 Table 3. Bacterial strains and plasmids……………………...…...……………………..70 Table 4. Primers used in this study………………………………...……………...……72 Table 5. Analysis of tetrameric repeat regions…………………..…………………......83 Table 6. Surface expression of PCho as assessed by colony immunoblotting….....…..94 Table 7. Real time PCR primers…………………...………………………………….113 Table 8. Inhibition of DPD depletion…………………...…………………………….124 Table 9. Analysis of tetrameric repeat regions…………………………...…………...140 Table 10. Primers used in this study……………………………………………………153 Table 11. Bacterial strains………………………………………………………………187 Supplemental Table 1. 2D gel analysis of M. catarrhalis biofilms established in the presence or absence of DPD……………………………....253 vii ABBREVIATIONS H. influenzae, Hi, NTHI Haemophilus influenzae M. catarrhalis, Mcat Moraxella catarrhalis S. pneumoniae, pneumococcus Streptococcus pneumoniae S. aureus Staphylococcus aureus E. coli Escherichia coli S. pyogenes Streptococcus pyogenes P. aeruginosa Pseudomonas aeruginosa K. pneumoniae Klebsiella pneumoniae P. melaninogenica Prevotella melaninogenica S. oralis Streptococcus oralis A. naeslundii Actinomyces naeslundii S. sanguinis Streptococcus sanguinis S. gordonii Streptococcus gordonii P. gingivalis Porphyromonas gingivalis S. mutans Streptococcus mutans S. oligofermentans Streptococcus oligofermentans S. salivarius Streptococcus salivarius S. sobrinus Streptococcus sobrinus S. anginosus Streptococcus anginosus V. harveyi Vibrio harveyi V. cholerae Vibrio cholerae viii A. actinomycetemcomitans Aggregatibacter actinomycetemcomitans luxS gene encoding the AI-2 synthase AI-2 autoinducer-2 DPD (S)-4,5-dihydroxy-2,3-pentanedione, AI-2 precursor Lsr LuxS regulated AHL/HSL acyl homoserine lactones, autoinducer-1 AIP autoinducer peptide PCho phosphorylcholine LOS lipooligosaccharide LPS lipopolysaccharide EPS
Load more

Recommended publications
  • Biofilm Formation by Moraxella Catarrhalis
    BIOFILM FORMATION BY MORAXELLA CATARRHALIS APPROVED BY SUPERVISORY COMMITTEE Eric J. Hansen, Ph.D. ___________________________ Kevin S. McIver, Ph.D. ___________________________ Michael V. Norgard, Ph.D. ___________________________ Philip J. Thomas, Ph.D. ___________________________ Nicolai S.C. van Oers, Ph.D. ___________________________ BIOFILM FORMATION BY MORAXELLA CATARRHALIS by MELANIE MICHELLE PEARSON DISSERTATION Presented to the Faculty of the Graduate School of Biomedical Sciences The University of Texas Southwestern Medical Center at Dallas In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY The University of Texas Southwestern Medical Center at Dallas Dallas, Texas March, 2004 Copyright by Melanie Michelle Pearson 2004 All Rights Reserved Acknowledgements As with any grand endeavor, there was a large supporting cast who guided me through the completion of my Ph.D. First and foremost, I would like to thank my mentor, Dr. Eric Hansen, for granting me the independence to pursue my ideas while helping me shape my work into a coherent story. I have seen that the time involved in supervising a graduate student is tremendous, and I am grateful for his advice and support. The members of my graduate committee (Drs. Michael Norgard, Kevin McIver, Phil Thomas, and Nicolai van Oers) have likewise given me a considerable investment of time and intellect. Many of the faculty, postdocs, students and staff of the Microbiology department have added to my education and made my experience here positive. Many members of the Hansen laboratory contributed to my work. Dr. Eric Lafontaine gave me my first introduction to M. catarrhalis. I hope I have learned from his example of patience, good nature, and hard work.
    [Show full text]
  • Helicobacter Pylori Outer Membrane Vesicles and the Host-Pathogen Interaction
    Helicobacter pylori outer membrane vesicles and the host-pathogen interaction Annelie Olofsson Department of Medical Biochemistry and Biophysics Umeå 2013 Responsible publisher under swedish law: the Dean of the Medical Faculty This work is protected by the Swedish Copyright Legislation (Act 1960:729) ISBN: 978-91-7459-578-9 ISSN: 0346-6612 New series nr: 1559 Cover: Electron micrograph of outer membrane vesicles Elektronisk version tillgänglig på http://umu.diva-portal.org/ Printed by: VMC-KBC, Umeå University Umeå, Sweden, 2013 Till min mormor och farfar i ii INDEX ABSTRACT iv LIST OF PAPERS v SAMMANFATTNING vi ABBREVIATIONS viii INTRODUCTION 1 BACKGROUND 2 The human stomach 2 Helicobacter pylori 3 Epidemiology 3 Gastric diseases 3 Clinical outcome 4 Treatment and disease determinants 5 The gastric environment and host cell responses 6 H. pylori colonization and virulence factors 8 cagPAI 9 CagA and apical junctions 11 The H. pylori outer membrane 12 Phospholipids and cholesterol 12 Lipopolysaccharides 13 Outer membrane proteins 14 Adhesins and their cognate receptor structures 14 Bacterial outer membrane vesicles 15 Vesicle biogenesis and composition 15 Biological consequences of vesicle shedding 18 Endocytosis and uptake of bacterial vesicles 19 Clathrin-mediated endocytosis 20 Clathrin-independent endocytosis 21 Caveolae 22 Modulation of host cell defenses and responses 23 AIM OF THESIS 24 RESULTS AND DISCUSSION 25 Paper I 25 Paper II 27 Paper III 28 Paper IV 31 CONCLUDING REMARKS 34 ACKNOWLEDGEMENTS 36 REFERENCES 38 iii ABSTRACT The gastric pathogen Helicobacter pylori chronically infects the stomachs of more than half of the world’s population. Even though the majority of infected individuals remain asymptomatic, 10–20% develop peptic ulcer disease and 1–2% develop gastric cancer.
    [Show full text]
  • Clinical Antibiotic Guidelines†
    CLINICAL ANTIBIOTIC GUIDELINES† ACYCLOVIR IV*/PO *RESTRICTED TO ANTIBIOTIC FORM Predictable activity: Unpredictable activity: No activity: Herpes Simplex Cytomegalovirus Epstein Barr Virus Herpes Zoster Indicated: IV: 1. Therapy for suspected or documented Herpes simplex encephalitis 2. Therapy for suspected or documented Herpes simplex infection of a newborn or immunocompromised patient 3. Therapy for primary varicella infection in immunocompromised patients 4. Therapy for severe or disseminated varicella-zoster infections in immunocompromised or immunocompetent patient 5. Therapy for primary genital herpes with neurologic complications Oral: 1. Therapy for primary Herpes simplex infections (oral/genital) 2. Suppressive (preventative) therapy for recurrent (³ 6 episodes/year) severe Herpes simplex infections (oral/genital) 3. Episodic therapy for recurrent (³ 6 episodes/year) Herpes simplex genital infections (initiate within 24 hours of prodrome onset) 4. Prophylaxis for HSV in bone marrow transplants where patient is seropositive 5. Therapy and suppressive therapy for Eczema Herpeticum 6. Therapy for varicella-zoster infections in immunocompetent and immunocompromised patients (if not severe) 7. Therapy for primary varicella infections in pregnancy 8. Therapy for varicella in immunocompetent patients > 13 years old (initiate within 24 hours of rash onset) 9. Therapy for varicella in patients < 13 years old (initiate within 24 hours of rash onset) if there is a chronic cutaneous or pulmonary disorder, long term salicylate therapy, or short, intermittent or aerosolized corticosteroid use Not Indicated: 1. Therapy for acute Epstein-Barr infections (acute mononucleosis) 2. Therapy for documented CMV infections CLINICAL ANTIBIOTIC GUIDELINES† AMIKACIN RESTRICTED TO ANTIBIOTIC FORM Predictable activity: Unpredictable activity: No activity: Enterobacteriaceae Staphylococcus spp Streptococcus spp Pseudomonas spp Enterococcus spp some Mycobacterium spp Alcaligenes spp Anaerobes Indicated: 1.
    [Show full text]
  • BIAXIN® XL Filmtab® (Clarithromycin Extended-Release Tablets) BIAXIN® Granules (Clarithromycin for Oral Suspension, USP)
    dn2871v1-biaxin-redline-2013-oct-25 BIAXIN® Filmtab® (clarithromycin tablets, USP) BIAXIN® XL Filmtab® (clarithromycin extended-release tablets) BIAXIN® Granules (clarithromycin for oral suspension, USP) To reduce the development of drug-resistant bacteria and maintain the effectiveness of BIAXIN and other antibacterial drugs, BIAXIN should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. DESCRIPTION Clarithromycin is a semi-synthetic macrolide antibiotic. Chemically, it is 6-0­ methylerythromycin. The molecular formula is C38 H69 NO13 , and the molecular weight is 747.96. The structural formula is: Clarithromycin is a white to off-white crystalline powder. It is soluble in acetone, slightly soluble in methanol, ethanol, and acetonitrile, and practically insoluble in water. BIAXIN is available as immediate-release tablets, extended-release tablets, and granules for oral suspension. Reference ID: 3599379 dn2871v1-biaxin-redline-2013-oct-25 Each yellow oval film-coated immediate-release BIAXIN tablet (clarithromycin tablets, USP) contains 250 mg or 500 mg of clarithromycin and the following inactive ingredients: 250 mg tablets: hypromellose, hydroxypropyl cellulose, croscarmellose sodium, D&C Yellow No. 10, FD&C Blue No. 1, magnesium stearate, microcrystalline cellulose, povidone, pregelatinized starch, propylene glycol, silicon dioxide, sorbic acid, sorbitan monooleate, stearic acid, talc, titanium dioxide, and vanillin. 500 mg tablets: hypromellose, hydroxypropyl cellulose, colloidal silicon dioxide, croscarmellose sodium, D&C Yellow No. 10, magnesium stearate, microcrystalline cellulose, povidone, propylene glycol, sorbic acid, sorbitan monooleate, titanium dioxide, and vanillin. Each yellow oval film-coated BIAXIN XL tablet (clarithromycin extended-release tablets) contains 500 mg of clarithromycin and the following inactive ingredients: cellulosic polymers, D&C Yellow No.
    [Show full text]
  • Use of the Diagnostic Bacteriology Laboratory: a Practical Review for the Clinician
    148 Postgrad Med J 2001;77:148–156 REVIEWS Postgrad Med J: first published as 10.1136/pmj.77.905.148 on 1 March 2001. Downloaded from Use of the diagnostic bacteriology laboratory: a practical review for the clinician W J Steinbach, A K Shetty Lucile Salter Packard Children’s Hospital at EVective utilisation and understanding of the Stanford, Stanford Box 1: Gram stain technique University School of clinical bacteriology laboratory can greatly aid Medicine, 725 Welch in the diagnosis of infectious diseases. Al- (1) Air dry specimen and fix with Road, Palo Alto, though described more than a century ago, the methanol or heat. California, USA 94304, Gram stain remains the most frequently used (2) Add crystal violet stain. USA rapid diagnostic test, and in conjunction with W J Steinbach various biochemical tests is the cornerstone of (3) Rinse with water to wash unbound A K Shetty the clinical laboratory. First described by Dan- dye, add mordant (for example, iodine: 12 potassium iodide). Correspondence to: ish pathologist Christian Gram in 1884 and Dr Steinbach later slightly modified, the Gram stain easily (4) After waiting 30–60 seconds, rinse with [email protected] divides bacteria into two groups, Gram positive water. Submitted 27 March 2000 and Gram negative, on the basis of their cell (5) Add decolorising solvent (ethanol or Accepted 5 June 2000 wall and cell membrane permeability to acetone) to remove unbound dye. Growth on artificial medium Obligate intracellular (6) Counterstain with safranin. Chlamydia Legionella Gram positive bacteria stain blue Coxiella Ehrlichia Rickettsia (retained crystal violet).
    [Show full text]
  • Moraxella Catarrhalis and Haemophilus Influenzae
    The Other Siblings: Respiratory Infections Caused by Moraxella catarrhalis and Haemophilus influenzae Larry Lutwick, MD, and Laila Fernandes, MD Corresponding author Moraxella catarrhalis Larry Lutwick, MD Infectious Diseases (IIIE), VA Medical Center, 800 Poly Place, Bacteriology Brooklyn, NY 11219, USA. M. catarrhalis is a Gram negative, aerobic diplococcus E-mail: [email protected] that was initially described by Anton Ghon and Rich- Current Infectious Disease Reports 2006, 8:215–221 ard Pfeiffer as Micrococcus catarrhalis at the end of the Current Science Inc. ISSN 1523-3847 19th century. For most of the first century of its rec- Copyright © 2006 by Current Science Inc. ognition, M. catarrhalis is considered to be a human mucosal commensal organism based on its common finding as an inhabitant of the oropharynx of healthy Respiratory infections remain substantial causes of mor- adults. During a significant amount of this time, based bidity and mortality globally. In this paper, two substantial on phenotypic characteristics as well as microbiologic players in bacterial-associated respiratory disease are colony appearances, the diplococcus was referred to assessed as to their respective roles in children and adults as Neisseria catarrhalis. Of note, in 1963, N. catarrhalis and in the developed and developing world. Moraxella was found to contain two distinct species, catarrhalis catarrhalis, although initially thought to be a nonpathogen, and cinerea [1]. continues to emerge as a cause of upper respiratory Reclassification of the genus of this microorganism disease in children and pneumonia in adults. No vaccine occurred in 1970 when significant phylogenetic dispari- is currently available to prevent M.
    [Show full text]
  • Atypica, and Granulicatella Adiacens in Biofilm of Complete Dentures
    [Downloaded free from http://www.j-ips.org on Thursday, November 1, 2018, IP: 183.82.145.117] Original Article Relative presence of Streptococcus mutans, Veillonella atypica, and Granulicatella adiacens in biofilm of complete dentures Binoy Mathews Nedumgottil Department of Prosthodontics and Implantology, Mahe Institute of Dental Sciences and Hospital, Puducherry, India Abstract Aims and Objective: Oral biofilms in denture wearers are populated with a large number of bacteria, a few of which have been associated with medical conditions such as sepsis and infective endocarditis (IE). The present study was designed to investigate the relative presence of pathogenic bacteria in biofilms of denture wearers specifically those that are associated with IE. Methods: Biofilm samples from 88 denture wearers were collected and processed to extract total genomic DNA. Eight of these samples were subjected to 16S rRNA gene sequencing analysis to first identify the general bacterial occurrence pattern. This was followed by species-specific quantitative polymerase chain reaction (qPCR) on entire batch of 88 samples to quantify the relative copy numbers of IE-associated pathogens. Results: 16S rRNA gene analysis of eight biofilm samples identified bacteria from Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, and Fusobacteria species. Interestingly, Streptococcus mutans, Veillonella atypica, and Granulicatella adiacens from Firmicutes, all known to be associated with early-onset sepsis and IE was present in five of eight biofilm samples. The other three samples carried bacteria from genus Proteobacteria with Neisseria flava and Neisseria mucosa, which are known to be commensals, as dominant species. Species-specific qPCR of S. mutans V. atypica, and G. adiacens on 88 biofilm DNA samples identified the presence of S.
    [Show full text]
  • Infectious Organisms of Ophthalmic Importance
    INFECTIOUS ORGANISMS OF OPHTHALMIC IMPORTANCE Diane VH Hendrix, DVM, DACVO University of Tennessee, College of Veterinary Medicine, Knoxville, TN 37996 OCULAR BACTERIOLOGY Bacteria are prokaryotic organisms consisting of a cell membrane, cytoplasm, RNA, DNA, often a cell wall, and sometimes specialized surface structures such as capsules or pili. Bacteria lack a nuclear membrane and mitotic apparatus. The DNA of most bacteria is organized into a single circular chromosome. Additionally, the bacterial cytoplasm may contain smaller molecules of DNA– plasmids –that carry information for drug resistance or code for toxins that can affect host cellular functions. Some physical characteristics of bacteria are variable. Mycoplasma lack a rigid cell wall, and some agents such as Borrelia and Leptospira have flexible, thin walls. Pili are short, hair-like extensions at the cell membrane of some bacteria that mediate adhesion to specific surfaces. While fimbriae or pili aid in initial colonization of the host, they may also increase susceptibility of bacteria to phagocytosis. Bacteria reproduce by asexual binary fission. The bacterial growth cycle in a rate-limiting, closed environment or culture typically consists of four phases: lag phase, logarithmic growth phase, stationary growth phase, and decline phase. Iron is essential; its availability affects bacterial growth and can influence the nature of a bacterial infection. The fact that the eye is iron-deficient may aid in its resistance to bacteria. Bacteria that are considered to be nonpathogenic or weakly pathogenic can cause infection in compromised hosts or present as co-infections. Some examples of opportunistic bacteria include Staphylococcus epidermidis, Bacillus spp., Corynebacterium spp., Escherichia coli, Klebsiella spp., Enterobacter spp., Serratia spp., and Pseudomonas spp.
    [Show full text]
  • Atypical, Yet Not Infrequent, Infections with Neisseria Species
    pathogens Review Atypical, Yet Not Infrequent, Infections with Neisseria Species Maria Victoria Humbert * and Myron Christodoulides Molecular Microbiology, School of Clinical and Experimental Sciences, University of Southampton, Faculty of Medicine, Southampton General Hospital, Southampton SO16 6YD, UK; [email protected] * Correspondence: [email protected] Received: 11 November 2019; Accepted: 18 December 2019; Published: 20 December 2019 Abstract: Neisseria species are extremely well-adapted to their mammalian hosts and they display unique phenotypes that account for their ability to thrive within niche-specific conditions. The closely related species N. gonorrhoeae and N. meningitidis are the only two species of the genus recognized as strict human pathogens, causing the sexually transmitted disease gonorrhea and meningitis and sepsis, respectively. Gonococci colonize the mucosal epithelium of the male urethra and female endo/ectocervix, whereas meningococci colonize the mucosal epithelium of the human nasopharynx. The pathophysiological host responses to gonococcal and meningococcal infection are distinct. However, medical evidence dating back to the early 1900s demonstrates that these two species can cross-colonize anatomical niches, with patients often presenting with clinically-indistinguishable infections. The remaining Neisseria species are not commonly associated with disease and are considered as commensals within the normal microbiota of the human and animal nasopharynx. Nonetheless, clinical case reports suggest that they can behave as opportunistic pathogens. In this review, we describe the diversity of the genus Neisseria in the clinical context and raise the attention of microbiologists and clinicians for more cautious approaches in the diagnosis and treatment of the many pathologies these species may cause. Keywords: Neisseria species; Neisseria meningitidis; Neisseria gonorrhoeae; commensal; pathogenesis; host adaptation 1.
    [Show full text]
  • Characterization of the Molecular Interplay Between Moraxella Catarrhalis and Human Respiratory Tract Epithelial Cells
    Characterization of the Molecular Interplay between Moraxella catarrhalis and Human Respiratory Tract Epithelial Cells Stefan P. W. de Vries, Marc J. Eleveld, Peter W. M. Hermans¤, Hester J. Bootsma* Laboratory of Pediatric Infectious Diseases, Radboud University Medical Centre, Nijmegen, The Netherlands Abstract Moraxella catarrhalis is a mucosal pathogen that causes childhood otitis media and exacerbations of chronic obstructive pulmonary disease in adults. During the course of infection, M. catarrhalis needs to adhere to epithelial cells of different host niches such as the nasopharynx and lungs, and consequently, efficient adhesion to epithelial cells is considered an important virulence trait of M. catarrhalis. By using Tn-seq, a genome-wide negative selection screenings technology, we identified 15 genes potentially required for adherence of M. catarrhalis BBH18 to pharyngeal epithelial Detroit 562 and lung epithelial A549 cells. Validation with directed deletion mutants confirmed the importance of aroA (3-phosphoshikimate 1-carboxyvinyl-transferase), ecnAB (entericidin EcnAB), lgt1 (glucosyltransferase), and MCR_1483 (outer membrane lipoprotein) for cellular adherence, with ΔMCR_1483 being most severely attenuated in adherence to both cell lines. Expression profiling of M. catarrhalis BBH18 during adherence to Detroit 562 cells showed increased expression of 34 genes in cell-attached versus planktonic bacteria, among which ABC transporters for molybdate and sulfate, while reduced expression of 16 genes was observed. Notably, neither the newly identified genes affecting adhesion nor known adhesion genes were differentially expressed during adhesion, but appeared to be constitutively expressed at a high level. Profiling of the transcriptional response of Detroit 562 cells upon adherence of M. catarrhalis BBH18 showed induction of a panel of pro- inflammatory genes as well as genes involved in the prevention of damage of the epithelial barrier.
    [Show full text]
  • 510(K) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY and INSTRUMENT CO M BINATIO N TEMPLATE Xpert CT/NG Package I
    510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY AND INSTRUMENT CO M BINATIO N TEMPLATE A. 510(k) Number: k121710 B. Purpose for Submission: To obtain substantial equivalence determination for the Xpert® CT/NG Assay C. Measurand: Genomic DNA of Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) D. Type of Test: Real Time Polymerase Chain Reaction (PCR) E. Applicant: Cepheid F. Proprietary and Established Names: Xpert® CT/NG Assay G. Regulatory Information: 1. Regulation section: 21 CFR 866.3120 Chlamydia serological reagents 21 CFR 866.3390 Neisseria spp. direct serological test reagents 21 CFR 862.2570 Instrumentation for clinical multiplex systems 2. Classification: Class II 3. Product code: Xpert CT/NG Package Insert – IVD Page 1 of 40 MKZ: DNA Probe, Nucleic Acid Amplification, Chlamydia LSL: DNA-Reagents, Neisseria OOI: Real Time Nucleic Acid Amplification System 4. Panel: Microbiology 083 H. Intended Use: 1. Intended use(s): Xpert® CT/NG Assay The Xpert® CT/NG Assay, performed on the GeneXpert® Instrument Systems, is a qualitative in vitro real-time PCR test for the automated detection and differentiation of genomic DNA from Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) to aid in the diagnosis of chlamydial and gonorrheal urogenital disease. The assay may be used to test the following specimens from asymptomatic and symptomatic individuals: female and male urine, endocervical swab, and patient-collected vaginal swab (collected in a clinical setting). Ancillary Specimen Collection Kits Cepheid® Xpert® CT/NG Vaginal/Endocervical Specimen Collection Kit The Cepheid® Xpert® CT/NG Vaginal/Endocervical Specimen Collection Kit is designed to collect, preserve and transport patient Chlamydia trachomatis and Neisseria gonorrhoeae DNA in endocervical and vaginal specimens from symptomatic and asymptomatic individuals prior to analysis with the Cepheid Xpert CT/NG Assay.
    [Show full text]
  • Pneumonia Panel
    Guidance on Use of the Pneumonia Panel for Respiratory Infections Although the number of pathogens that cause pneumonia is lengthy, establishing the microbiologic etiology of pneumonia is inherently difficult. A recent large multi-center study of community-acquired pneumonia (CAP) found that only 38% of 2259 CAP cases had a microbiologic diagnosis with 23% having viruses detected, 11% bacterial, and 3% had both viruses and bacteria detected.1 Current tools to assist in pneumonia diagnosis include respiratory tract cultures (sputum, BAL, tracheal aspirate, mini-BAL), urine antigens (pneumococcal, Legionella), serology, and PCR for viral and certain bacterial pathogens. While these tools are useful, the study noted above used all these tools and was unable to document an etiology causing pneumonia in 62% of patients. Thus, more sensitive tools for detection of respiratory pathogens are still needed. Nebraska Medicine has recently introduced a new FDA-approved multiplex PCR panel to assist in determination of the etiology of pneumonia, termed the Pneumonia Panel (PP). This test uses a nested multiplex PCR- approach to amplify nucleic acid targets directly from sputum or bronchoalveolar lavage (BAL) in patients with suspected pneumonia. The list of pathogens and resistance genes included in the panel is found in Table 1. Note that the bacterial targets are detected semi-quantitatively whereas the atypical pathogens and the viral targets are detected qualitatively. Table 1: Pneumonia Panel Pathogen Targets and Associated Resistance Genes Semi-quantitative Detection: Gram Positive Organisms: Resistance Genes (Staph aureus only): Staphylococcus aureus mecA/C and MREJ Streptococcus pneumoniae Streptococcus agalactiae Streptococcus pyogenes Gram Negative Organisms: Resistance Genes (All Gram Negatives): Acinetobacter calcoaceticus-baumannii complex CTX-M Enterobacter cloacae complex IMP E.
    [Show full text]