Morphology, classification, Pathogens, treatment

1. Klebsiella
Mohammad Arif, 930
Microbiology

2. Klebsiella
Klebsiella (lat. Klebsiella) is a rod-shaped
microorganism of the enterobacteriaceae family.
Klebsiels are named after the German bacteriologist E.
Klebs, who discovered Klebsiels in the tissues of
patients who died from pneumonia (1875). The pure
culture of Klebsiel was first identified by the German
pathologist K. Friedlander (1882).

3. Klebsiella classification
There are four types of the Klebsiella genus:
- K.pneumoniae (or Frenlander's bacillus, who in
1882 isolated a bacterium that had a pronounced
capsule, the causative agent of pneumonia);
- K. rhinoscleromatis (Volkovich-Frisch stick,
causative agent of rhinoscleroma);
- K. ozaenae (Abel's wand, causative agent of a fetid
rhinitis);
- additional species: K. aerogenes, K. edwardsii var.
edwardsii and var, K. oxytoca.

4. The most common is the so-called Friedlander's
bacillus (in most cases, causing pneumonia -
pneumonia) and Klebsiella oxytoca, which causes
damage to the colon.
This microorganism belongs to the group of
conditionally pathogenic flora. This term means that
Klebsiella lives in the body of perfectly healthy people.
Moreover, it is one of the elements of the normal
intestinal flora. Normally, klebsiella can also parasitize
on the skin, in the respiratory tract (on the mucous
membrane).

5. If the human body is weakened for one reason or
another, Klebsiella begins to multiply actively, causing
inflammatory processes in various organs.
In the body, Klebsiella has a rod-like shape, but when
it gets into the environment, it is somewhat rounded
and covered with a special shell - a capsule. Thanks to
this adaptation, bacteria of the genus klebsiella are
very resistant to environmental factors.

6. Klebsiel morphology. Cultural properties of Klebsiel.
Klebsiel antigens. Antigenic structure of Klebsiel.
Klebsiella - thick short rods measuring 2-5 * 0.3-1.25
microns, with rounded ends, motionless. Do not form a
dispute. In smears, they are arranged in pairs or singly,
usually surrounded by a capsule, gram-negative. Grow well
on simple nutrient media at 35-37 ° C. On meat-peptone
agar, cloudy mucous colonies are formed, in broth - intense
turbidity. The nature of growth on agar and enzymatic
properties are shown in table. 6. Klebsiella do not form
exotoxins, contain endotoxins. Capsular bacteria include
three antigens: capsular (K-antigen), somatic smooth (O-
antigen), somatic rough (R-antigen); K- and O-antigens are
carbohydrates, R-antigen is a protein.

7. The resistance of Klebsiella is quite high: at room
temperature they persist for months, when heated to 65 °
C they die within an hour. Sensitive to the action of
various disinfectants: chloramine solution, phenol, etc.
The virulence of Klebsiella is associated with the presence
of capsules in them. Bacteria that have lost the capsule
become non-virulent and, when introduced into the
animal's body, quickly phagocytose. Capsular variants
cause death of mice within 24-48 hours after infection
with seeding of all organs.

8. Klebsiella cells have the shape of an irregular oval. The
Klebsiel capsule is usually present in strains directly
isolated from humans and animals. After replanting on
nutrient
environment, under the influence of low temperature,
immune serum and / or antibiotics Klebsiela can lose the
ability to capsule formation.
Under the action of antibiotics, Klebsiels are capable of
forming L-forms in some cases.

9. Pathogenesis of human diseases.
Klebsiella pneumonia (Friedlander's bacillus) was initially
considered to be causative agents of respiratory diseases
(rhinoscleroma, ozena, pneumonia). Then it was found that
they can cause damage to the mucous membranes of the
eyelids, urogenital organs, as well as the meninges, joints,
can cause sepsis, acute intestinal infections in adults and
children, purulent postpartum complications. Infection of
newborns can lead to the development of severe
pneumonia, intestinal infections, toxic-septic conditions
with a fatal outcome.

10. Klebsiella are considered the causative agents of
nosocomial infections. They are common with mixed
infections. However, pneumonia constitutes an
insignificant part of Klebsiellosis and usually develops
in persons with respiratory tract lesions or against the
background of a general weakening of the body.
Pneumonia is accompanied by active destruction of the
pulmonary parenchyma with the formation of
abscesses, empyema and pleural adhesions. Somewhat
more often, the pathogen causes hospital respiratory
tract lesions (bronchitis and bronchopneumonia)

11. Klebsiella ozenes (Abel's bacillus) are an etiological factor
in chronic diseases of the respiratory system. The
inflammatory process is accompanied by the release of a
viscous secretion, emitting a fetid odor. The course of the
disease is chronic; the incubation period has not been
established. Most often, ozena begins at 8 ~ 16 years, and
clinical manifestations reach a maximum by 35-40 years.
The clinical picture of Ozena is characterized by a triad of
signs, atrophy of the mucous membrane of the nose and
the underlying bone skeleton, the formation of dense
crusts and an unpleasant odor from the nose. The process
can spread to the pharynx, larynx and trachea and lead to
loss of smell.

12. Diagnostics of Klebsiel. Microbiological diagnostics of
Klebsiella
The principles of microbiological diagnosis of Klebsiella
are based on the isolation and identification of the
pathogen.
It is carried out using microbiological and serological
methods. Test material: sputum (with pneumonia),
mucus from the pharynx, nose, trachea (with osen),
pieces of tissue from granulomas (with rhinoscleroma).

13. Serological diagnosis is carried out by staging a
complement fixation test and an agglutination
test. The antigenic structure of Klebsiella is
investigated in RA of a living culture with
diagnostic K-antisera. To detect AT, RSK is used
(daily culture is used as Ag) or the reaction of O-
agglutination (Ag is a daily capsule-free culture).
An allergic skin test is used as an auxiliary
method, but it is less specific than serological
reactions.