Corynebacterium diphtheriae is the bacterium that causes diphtheria. It is a Gram-positive, non-motile rod that can form club-like swellings. Diphtheria causes inflammation of mucous membranes and skin lesions, as well as general intoxication and damage to cardiovascular and nervous systems from its exotoxin. Symptoms include sore throat and grayish-white deposits on the tonsils and pharynx. The disease was first described in 1826 and the bacterium was identified in 1883. Immunization with DTP vaccine is used for prophylaxis starting at 3 months of age.

1. Corynebacterium diphtheriae

2. Corynebacteria are
Gram-positive,
non-acid fast,
non-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.

13. Pathogenicity

14. 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.

15. 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

16. Clinical severity:
-Malignant or hypertoxic
-Septic
-Hemorrhagic

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

18. 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.

19. 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

20. 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

21. 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.