description of corynebacterium diptheria

1. Corynebacterium
• General properties:
a) Gram positive bacilli
b) Non capsulated
c) Non sporing
d) Non motile
e) Club shaped
f) Diphtheria
g) C.ultricans and pseudotuberculosis
Dr Amit kumar
amitkumarshahi90@gmail.com

2. Corynebacterium diptheriae
• A) club shaped
• B) gpb
C) Chinese letter or culiform
• D) Metachromatic granules
• a/c polar bodies or babes ernst bodies

3. • Polymetaphosphate
• Loeffler’s methylene blue stain : bluish purple
• Granules :

4. History

5. Virulence factor
• Diptheria toxin
B
A
INHIBIT PROTEIN
SYNTHESIS BY
ADP EF2
INHIBIT
TRANSLATION
HELIP ENTERY: A
BIND RECEPTOR
ENTER INTO
ENDOSOME (ENDOCYTOSIS)
TRYPSIN ENZYME
A
B

7. FACTORS REGULATION TOXIN PRODUCTION
• 1) PHASE CODE: beta corynephage (tox gene)
• 2) iron concentration : high iron (inhibit toxin)
• 3) DT repressor gene : uptake of iron

8. Pathogenesis and clinical manifestation
• Pathogenesis exotoxin
• Toxemia never bacteraemia
• Toxin : respiratory and systemic manifestation
(except cutaneous : bacilli)
• Types of diptheria: respiratory , cutaneous ,
systemic
•

10. • Respiratory diphtheria :
• Tonsil and larynx (faucial) (inflammatory) necrosis of epithelial cells mucosal ulcer (pseudomembrane )
air obstruction: asphyxia (tracheostomy)
bulk neck
3-4
days
Extension :
pseudomembrane
Severe case:
tonsillar swelling
neck edema

12. Cutaneous diptheria
• m/c sites : extremeties
• Ulcerative with necrosis (rarely
pseudomembrane)
• Organism itself not by toxin
• Nontoxin starins : responsible
• Vaccination : not protected

13. Systemic diptheria
• Polynephritis and myocarditis
• Others: pneumonia , renal failure , encephalitis , cerebral
infraction and pulmonary embolism
• Neurological manifestation : toxin mediated
noninflammatory demyelination
• Cranial nerve involvement
• Peripheral neuropathy
• Ciliary paralysis
• Myocarditis: arrhythamias and dialated cardiomyopathy

14. Laboratory diagnosis

15. • 1) Specimen: throat swab , portion of pseudomembrane , skin
• 2) direct microscopy :
• A) gram stain:
• b) Albert stain :
A
B

16. 3) CULTURE
• BLOOD AGAR : SMALL CIRCULAR , WHITE , HEMOLYTIC
• Loeffler’s serum slope: small , circular , glistering and white
with yellow tinge

17. • hoyle;’s potassium tellurite agar :
Black colour colony

18. 4) Biochemical identification
• 1) Hiss’s serum sugar media:
• glucose and maltose : all biotype
• starch: gravis
• Acid but no gas
• 2) pyrazinamidase test :
• Ngative : C.diptheriae , c.ultricans and c.pseudotuberculosis
• 3) urease test
• Negative : C.diptheriae
• Positive :c.ultricans and c.pseudotuberculosis

19. 5) Toxin demonstration
In vivo: animal
inoculation
Invitro :Elek’s gel
precipttation

20. 6) Epidemiology
• Source of infection :
• carrier (95%) than case(5%)
• Transmission : aerosol or contact (rarely)
• Age : children (1-5 years)

21. 7) Prophylaxis
DPT VACCINE :
Active immunization
Donot effect
On cutaneous diptheria
Elimination of carrier state

22. • Type of vaccine
• Single vaccine : diptheria toxoid (alam or formal
precipitad vaccine)
• Combined vaccine : DPT (PERTUSSIS act as adjuvant)
• Type of DPT vaccine
• Plain formal toxoid : formalin
• Absorbed: alum (aluminium hydroxide) act as adjuvant

23. • Administration :
• Schedule: 5 doses (6 , 10 ,14 and 2 booster doses at 16-24 months)
• Site :intramuscular
• Dose :0.5 ml

24. • Td : contain TT and adult dose of diphtheria Recommended after 7 years
• Tdap: adult tetanus- diphtheria - acellular pertussis safely use for
adult.devoid neurological complication
• Adverse reactions: fever , local reactions
Killed pertussis is encephalitogenic (dont for after 6 years)
Contraindications
Hypersensitivity to previous dose
Neurological dissorde