Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring-...

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Transcript of Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring-...

Page 1: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.
Page 2: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Introduction

• Klebs--1883 discovered• Loefflers--1884 cultured• Also known as KLB • Emil von Behring- 1890

produced antitoxin• Awarded nobel prize

Emil Von Behring

Page 3: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Morphology

• Gram positive bacilli. 3-6 μ x 0.5-0.8 μ.• v or k or L shape.• Chinese letter pattern, angular arrangement• Metachromatic granules. volutin granules,

polymetaphosphate energy storage depots• Alberts stain – green and bluish black• Nonmotile noncapsulated, nonsporing• pleomorphic

Page 4: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.
Page 5: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Cultivation

• Loefflers serum slope– creamy white colonies in 6-8 hrs

• Potassium tellurite medium—black colonies

• Blood agar

Page 6: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.
Page 7: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Biochemical reactions

• Hiss serum

• Ferments glucose ,maltose with acid only

• Lactose, sucrose, mannitol not fermented

• Urease negative

• Starch –only gravis type, not intermedius or mitis

Page 8: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Pathogenicity

• Produces exotoxin

• Lysogenic conversion with beta phage

• Toxin – heat labile protein

• A and B fraction

• Toxicity- disease

• Antigenicity- immunity

• Toxoid – toxin without toxicity

Page 9: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Toxin

Mechanism of action

-B subunit binds to receptor-toxin molecule cleaved at protease sensitive site between A-B portion (remain bonded by disulfide link)-receptor-toxin complex englufed into vesicle of host cell-reduction of disulfide bond, A subunit released into cytoplasm-Necrosis/neuotoxic effects on organism by exotoxin

Page 10: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Biotypes

1)gravis(13 types)-most serious diseaseColonies: large, irregular, gray

2)mitis(40 types)-mild illnesscolonies: small, round, convex, black

3)intermedius(4 types)-intermediate severityColonies: small, flat and gray

Page 11: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Diphtheria

• Children, fatal if not treated in time• Exclusively human disease• Droplet infection- fomites• Fever, cervical lymphadenopathy,

pseudomembrane• Myocarditis arrhythmia fatal• Polyneuropathy, paltine paralysis• Rare in adults.

Page 12: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Pseudomembrane formation

Thick membrane lining throat that interferes with eating, drinking and breathingContents: WBC, RBC, bacteria, disintegrating epithelial cellsCause: fibrinous exudate from local necrosis by exotoxin (removal of PF may cause bleeding)Localization: faucial, laryngeal, nasal, otitic, conjunctival, genital, cutaneous

Page 13: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Faucial:

Signs: sore throat, fevercomplications: prostration, dyspnea, asphyxia, arhythmia,

difficulties of speech, vision, swallowing, movement

Septic: Ulceretic:

Page 14: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Clinical classification

i) Malignant (hypertoxic) diphtheria Signs: severe toxemia and adenitis, lymph glands swelling in the neck

Complications: death-circulatory failure, paralytic sequelaeii) Septic diphtheria:

Signs: ulceration with pseudomembrane formation and cellulites (gangrene around pm)

iii) Hemorrhagic diphtheriaSigns: local and general bleeding from edge of psudomembrane, conjunctival, epistaxis and purpura

Page 15: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Complications

1)Asphyxia-obstruction of resp tract2)Acute circulatory failure3)kidney failure 4)paralysis-soft palate, eye muscles, extremities (3rd-4th week)5)septic sequelae-pnemonia, otitis media

 

Page 16: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Laboratory diagnosis

• Sample collection: Throat swab or swab from membrane

• Microscopy: Gram stain and Alberts stain

• Culture: Loefflers and PT

• Biochemicals

• Virulence test in vivo and in vitro

Page 17: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Virulence test contd

In vivoGuinea pig– subcutaneous

intradermal

Test and control animals to be used

In vitro

Eleks gel precipitation test

Page 18: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Toxigenicity test (virulence test)

i) Animal inocculation-bacteria culture emulsified in water and 0.8 ml injected into 2 guinea pigsGP A-has dipht antitoxin (injected 2 hours before)GP B-Doesn't have antitoxin

Result: Guinea pig B dies.

ii) Elek's gel precipitation test-filter paper saturated with antitoxin is placed on agar plate with 20% horse serum-bacterial culture streaked at right angles to filter paper

iii) tissue culture test-incorporation of bacteria into agar overlay of eukaryotic cell culture monolayers.Result: toxin diffuses into cells and kills them

iv) PCR assays-test presence of specific bacteriophate gene (tox)

Page 19: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Elek's gel precipitation test

Page 20: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

EPIDEMIOLOGYEPIDEMIOLOGY

• Formally important pediatric diseaseFormally important pediatric disease• Developed countries - EradicatedDeveloped countries - Eradicated• Developing countries serious problemDeveloping countries serious problem• Rare in 1Rare in 1stst year – maternal antibodies year – maternal antibodies• Peak 1-5 years, 5-10 years- decreases there afterPeak 1-5 years, 5-10 years- decreases there after• Immunity – sub clinical infectionsImmunity – sub clinical infections• Carriers outnumber cases – throat & nasalCarriers outnumber cases – throat & nasal• Rarely spread through milkRarely spread through milk

Page 21: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Prevention• Active immunity- DPT dosage

– Antitoxin level – 0.01/ ml protectiveAntitoxin level – 0.01/ ml protective

• Passive immunity- ADS– When susceptibles are exposedWhen susceptibles are exposed– 500 – 1000 units sc of Anti Diphtheritic Serum ( ADS)500 – 1000 units sc of Anti Diphtheritic Serum ( ADS)

• Combined immunisation– First dose of adsorbed toxoid on one armFirst dose of adsorbed toxoid on one arm– ADS on another armADS on another arm– To be continued with full course of active To be continued with full course of active

immunizationimmunization

Page 22: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Preventiona) DTP (DPT)- • Formal toxoid - Incubation of Toxin at pH 7.4 -7.6 for 3 – Formal toxoid - Incubation of Toxin at pH 7.4 -7.6 for 3 –

4 weeks at 37 4 weeks at 37 °°C C • Adsorbed toxoid – purified toxoid adsorbed on to Adsorbed toxoid – purified toxoid adsorbed on to

aluminum phosphate or hydroxidealuminum phosphate or hydroxide

• triple vaccine given to children.

trivalent preparation

• Diphtheria toxoid, Tetanus toxoid and Pertussis vaccine

Td- contains absorbed tetanus and ten-fold smaller dose of diphtheria toxoid.

Page 23: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

b) Schedule

i) primary immunization –

- infants and children - 3 doses, 4-6 weeks - 4th dose after a year - booster at school entry

ii) Booster immunization

- adults - Td toxoids used (traveling adults may need more)

Shick test-to test sensitivity (allergic reaction)

Page 24: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Treatment

• Antitoxin – 20,000 to 1 lakh unitsAntitoxin – 20,000 to 1 lakh units

• Antibiotic therapy – PenicillinAntibiotic therapy – Penicillin

• Carriers - ErythromycinCarriers - Erythromycin

Page 25: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Patch in the throat

• Diphtheria

• Streptococcal tonsillitis

• Oral thrush– Candida albicans

• Spirochete- Borrelia vincenti

Page 26: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Other Corynebacteria

1. C. ulcerans:

– Diphtheria like lesions

– Spread thru milk

– Antitoxin protective, erythromycin

2. C.minutissimum- – Erythrasma

3. C. tenuis:- Trichomycosis axillaris

Page 27: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

4. C.pseudotuberculosis: – Veterinary importance

5. C.parvum:– Immunomodulator

6. A. haemolyticum:– pharyngitis, skin ulcers

7. C.jakieum:– Skin inf/ BSI in IC. Rx- Vancomycin.

Page 28: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.

Diphtheroids

• Morphologically resembling diphtheria but do not cause any disease.

• Present as commensals in throat, skin

• Do not contain metachromatic granules.

• Do not produce any toxin ie virulence test is negative.

• C.hofmani, C.xerosis, C.pseudodiphtheriticum

Page 29: Introduction Klebs--1883 discovered Loefflers--1884 cultured Also known as KLB Emil von Behring- 1890 produced antitoxin Awarded nobel prize Emil Von.