Corynebacteria
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Corynebacteria. Filename: Coryne.ppt. Outline. Microbes Corynebacterium ,Listeria, Erysipelothrix Diseases Diphtheria ,Listeriosis, Erysipeloid. Corynebacterium : Habitat. Skin upper respiratory tract GI tract Urogenital tract of humans. C. diphtheriae Diphtheria

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Corynebacteria

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Corynebacteria

Corynebacteria

Filename: Coryne.ppt


Outline

Outline

  • Microbes

    • Corynebacterium,Listeria, Erysipelothrix

  • Diseases

    • Diphtheria,Listeriosis, Erysipeloid


Corynebacterium habitat

Corynebacterium: Habitat

  • Skin

  • upper respiratory tract

  • GI tract

  • Urogenital tract of humans


Cornyebacterium pathogens

C. diphtheriaeDiphtheria

C.pseudotuberculosishumans sheep, cattle, suppurative lymphadenitis

C. ulceranshumans pharyngitis

cattle -mastitis

C. haemolyticumpharyngitis cutaneous infection

C.pyogenes cattle, sheep, swine suppurative infection

C.pseudodiphtheriticumendocarditis

Cornyebacterium: Pathogens


C xerosis

C. xerosis

opportunistic infections

Group J K immunocompromised host


Related organisms

Related Organisms

Listeria monocytogenes

  • Listeriosis

  • Erysipelothrix rhusiopathiae

    • Erysipeloid


  • Diphtheria

    Diphtheria


    Diphtheria laboratory diagnosis

    DiphtheriaLaboratory diagnosis

    • Speedy diagnosis

    • Differentiate from commensals

      • “diphteroids”

      • nose & throat

      • C. xerosis C. hofmanni

    • Throat swabs (confirmatory)

      • Blood Tellurite

    • Virulence test


    Corynebacterium

    Corynebacterium

    • Aerobic gram + rods

    • -pleomorphic: club-shaped

    • -pallisades

    • -snapping cell division

    • -metachromatic granules

      • methylene blue stain

      • volutin: polyphosphate


    Cellular morphology

    Cellular Morphology

    • Gram positive rods

    • “Snapping division”

    • Palisade cells

    • “Chinese letters”

    Erysipelothrix


    Specialized media

    Tellurite:

    black colonies

    Not diagnosticallly significant

    tellurite inhibits many organisms but not C. diphtheriae

    Loeffler

    best colonial morphology

    Dextrose horse serum (1887)

    now Dextrose beef serum

    Specialized media


    Blood tellurite

    Blood tellurite

    • Selective & differential medium

    • Corynebacteria are resistant to tellurite

      • Reduced to tellurium

    • Forms deposit in colonies

      • Colonies appear dark

    • Biotypes

      • gravis, intermedius, mitis


    Corynebacterium biotypes

    Corynebacterium Biotypes

    • C diphtheriaegravis

    • C diphtheriaeintermedius

    • C diphtheriaemitis

    • Helpful for epidemiological tracing

    • Culture identified by biochemical tests.


    Diphtheria1

    Diphtheria

    • Nasopharyngeal diphtheria

      • Pharyngeal

      • Larygngeal

    • Cutaneous diphtheria

    • Systemic complications

    DIAGNOSIS MUST BE CLINICAL!!!!


    Pharyngeal diptheria

    Pharyngeal diptheria

    • Inflammation

      • similar to strept throat

    • Leucocytes

      • infiltrated

      • killed

      • embedded in fibrin clot

    • TOXIN !!


    Diphtheria symptoms

    Diphtheria Symptoms

    • Pharyngitis

    • Hypoxia

      • Choking

      • “Garitillo”

    • Fever (103 F)

    • Lymphadenitis

    All SIGNS & SYMPTOMS CAUSED BY TOXIN


    Diphtheria pseudomembrane

    Diphtheria Pseudomembrane

    • No True membrane

    • Very few live cells

    • Deposit of dead cells and protein


    Pseudomembrane

    COVERS

    tonsils,

    uvula,

    palate

    nasopharynx

    larynx.

    Pseudomembrane

    • CONTAINS

      • bacteria

      • lymphocytes

      • plasma cells

      • fibrin

      • dead cells


    Diphtheria systemic complications

    DiphtheriaSystemic complications

    • Nerves

      • toxic peripheral neuropathy

      • paralysis of short nerves

      • mouth, eye, facial extremities

    • Cardiac

      • Congestive heart failure

      • high amount of toxin 48-72 hours

      • Low amount of toxin 2-6 weeks


    Virulence factors

    Virulence Factors

    • Diphtheria toxin !!!

      • blocks protein synthesis

    • Dermonecrotic toxin

      • sphingomyelinase

      • increases vascular permeability

    • Hemolysin

    • Cord factor -Toxic trehalose

      • corynemycolic acid, corynemyolenic acid

      • 6,6’-di-O-mycoloyl- a,a’-D-trehalose


    Diphtheriatoxin

    DiphtheriaToxin

    • Blocks protein synthesis

    • Protein 63Kd

    • controlled by Tox gene

    • lysogenic phage Beta-corynephage

    • expressed if [iron] low

    • 2 components A-B


    Regulation of diphtheria toxin high fe 2

    Regulation of Diphtheria Toxin High [Fe 2+]

    NO Toxin Produced

    P

    o

    tox

    Corynebacteriophage beta

    Fe 2+ + apo DtxR

    [Fe 2+*DtxR]

    p

    dtxR

    C diphtheriae

    dtxR= repressor protein


    Regulation of diphtheria toxin low fe 2

    P

    o

    tox

    Corynebacteriophage beta

    Regulation of Diphtheria Toxin Low [Fe 2+]

    Toxin Produced!!!

    Fe 2+ + apo DtxR

    [Fe 2+*DtxR]


    Toxin

    Toxin

    • Part A

      • Active site

      • N terminal

      • Enzyme

    • Part B

      • Binding site

      • Binds to membrane receptor

      • Transmembrane


    Diphtheria toxin part a

    Diphtheria toxin: Part A

    • Active site

    • Enzyme

    • Blocks protein synthesis

      • ADP-ribosyl transferase

      • elongation factor 2 (EF2)

    • Specific for mammalian cells

      • Prokaryotes have different EF2


    Diphtheria toxin part b

    Diphtheria Toxin: Part B

    • Binding Site

    • Binds to cell receptor

    • Bound receptor internalized

    • Endosome

      • Hydrolysed by protease

      • Disulfide broken

      • Part A released


    Activation of diphtheria toxin

    A

    A

    A

    B

    B

    B

    A

    B

    Activation of Diphtheria Toxin


    Toxingenicity tests

    Toxingenicity Tests

    In Vitro Elek test

    In Vivo Animal inoculation

    rabbit skin test-necrosis

    guinea pig challenge test- lethal

    low [Fe 2+] induces toxin


    Elek test

    Elek test


    Animal inoculation

    Animal inoculation

    Inject 2 mice with 5ml C.diphtheria cells

    one mouse protected with 1000 units C.diphtheriae antitoxin

    Autopsy - adrenals hemorrhagic


    Control

    Control

    • Immunization diphtheria toxoid

    • Schick test

      • check for antibodies

    • Passive immunity

      • Antibodies

    • Antibiotics

      • Penicillin & erythromcyin


    Schick test for diptheria

    Schick Test for Diptheria


    Epidemics

    Epidemics

    • Immune individuals

      • may be carriers

      • antibiotics

    • Non immune individuals

      • Exposed

        • passive immunity antibodies

      • Not exposed

        • immunize with toxoid


    Diphtheria russian federation

    Diphtheria: Russian Federation


    Diphtheria in the soviet union and nis

    Diphtheria in the Soviet Union and NIS

    Emerging infectious diseases: 4(4) 1998 Vitek & Wharton


    Diphtheria incidence

    Diphtheria Incidence


    Diphtheria in the russian federation

    Diphtheria in the Russian Federation


    The end

    The End


    Performance objectives

    Performance Objectives

    Key terms, concepts

    short answers


    Key terms

    pseudomembrane

    Key Terms


    Key terms1

    Schick test

    Elek Test

    Diphtheria toxin

    larnygeal diphtheria

    pharyneal diphtheria

    Key Terms


    Key organisms

    Corynebacterium

    Listeria

    Erysipelothrix

    Key Organisms


    Key concepts

    Key Concepts


    Epidemiology of diphtheria

    Epidemiology of Diphtheria

    • Disease/bacterial factors

    • Transmission

    • Who is at risk

    • Geography/ season

    • Incidence

    • Modes of control


    Short answers

    Short Answers

    • Construct a table of the virulence factors associated with diphtheria and the biological activity of each

    • Use a series of no more than four diagrams to describe the mechanism of action of diphtheria toxin

    • Describe the clinical manifestations of diphtheria

    • Construct a table listing the common Corynebacteria and the associated diseases.


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