Corynebacterium Diphtheriae

Corynebacterium Diphtheria
Incubation Period
Morphology

1. Corynebacterium diphtheriae

2. Corynebacteria are Gram-positive, non-acid fast, n on-motile rods with irregularly stained segments. They frequently show club-shaped swellings-hence, the name Corynebacterium ( from coryne , meaning club ) .

3. Diphtheria is an acute infectious disease characterized by inflammatory changes (the formation of specific films) on the mucous membranes or skin, phenomena of general intoxication and toxic damage to the cardiovascular and nervous systems.

4. The incubation period for diphtheria (the time from the moment of infection to the first clinical manifestations) is from 2-10 days (incubation period).

5. The disease begins like an ordinary sore throat: with malaise, sore throat, discomfort when swallowing, fever up to 38–39 ° С. Then, specific grayish-white deposits of a uniform dense consistency, uniform thickness with a smooth surface appear on the tonsils and pharynx.

6. The disease was first recognized as a clinical entity by Bretonneau (1826) who called it “ diphtherite “ (from diphtheros , meaning leather).

7. The diphtheria bacillus was first observed and by Klebs (1883) but was first cultivated by Loeffler 1884.

8. Roux and Yersin (1888 ) discovered the diphtheria exotoxin and established its pathogenic effect. The antitoxin was described by von Behring (1890).

9. MORPHOLOGY

10. The diphtheria bacillus is a slender rod with a tendency to clubbing at one or both ends. The bacilli are pleomorphic, measuring approximately 3-6 micrometer ˟ 0,6-0,8 micrometer. They are non- sporing , non-capsulated, non-motile .

11. Polymetaphosphate granules or metachromatic granules are a taxonomically indefinite group of asporogenic polymorphic grams + sticks located in the cytoplasm and having an irregular shape.

12. Pathogenicity

13. Toxin Virulent strains of diphtheria bacilli produce a very powerful exotoxin. The productivity of different strains, the amount of toxins is different, some are weak, others are in excess, but similar in quality.

14. The incubation period in diphtheria is commonly 3-4 days but may on occasion be as short as one day. Place of infection : - Otitic - Nasal - Genital: vulval , vaginal or prepucial - Pharyngeal (most common) - Laryngeal - Conjunctival - Cutaneous

15. Clinica l severity: - Malignant or hypertoxic - Septic - Hemorrhagic

16. С ommon complications are: - Asphyxia - Acute circulatory failure - Post-diphtheritic paralysis - Toxemia - Local necrotic changes - Mechanical changes - Non-Toxigenic strains

17. Laboratory diagnosis: A sample is taken from the affected area and a smear microscopy is performed after staining with methylene blue . Growing in a nutrient medium at an optimum temperature for growth is 37ᵒ С.

18. Epidemiology The antiepidemic measures in the epidemic outbreak are its localization and elimination. In the process of anti-epidemic measures are carried out: identification of patients, persons with suspected illness, carriers of toxigenic corynebacteria diphtheria and their hospitalization; identification of persons with pathology of ENT - organs and the conduct of appropriate medical and recreational activities

19. Prophylaxis Immunization with DTP vaccine starting from 3 months of age, which, in addition to diphtheria toxoid, includes pertussis vaccine and tetanus toxoid (for contraindications to the pertussis component, the ADT-M vaccine is used). Children are vaccinated 3 times at the age of 3, 4.5 and months; booster vaccination is carried out at the age of 18 months, 6-7 and 14 years . DTP is (Diphtheria, Pertussis and Tetanus) serum

20. DTP vaccine mechanism of action: DTP vaccine is available in the form of a liquid, unclear biological suspension. It consists of diphtheria toxoid, pertussis and tetanus serum components, made on the basis of weakened whole-cell cultures of pathogens of these diseases. This means that the pathogens of the infection are in the inactivation stage of the drug. The purpose of vaccination is to develop in children stable immune phagocytosis (protection) for each type of infectious pathogen.