Pneumopathies can have various origins.
Pneumopathies of bacterial origin; acute, purulent, with an alveolar attack, have a homogeneous opacity good limited on a thoracic radio (example: PFLA Frank Pneumonia Lobaire Acute, due to the Pneumococcus).
Pneumopathies of viral origin, are subaigues, with an attack of pulmonary conjunctive fabric, and present an image of infiltrates on a thoracic radiography.
Certain bacteria give pneumopathies of the viral type; among them, one finds Chlamydiae and Mycoplasme pneumoniae .
Diseases
Respiratory infection due to Mycoplasma pneumoniae
Clinical pneumopathy atypiqu, infection by the agent of Eaton
Beginning progressive, less brutal than traditional bacterial pneumopathy or the influenza.
- attack of the pulmonary parenchyma giving an indication of infiltrate to the thoracic radio.
Evolution
- Benign in general: in the form of tiny rhino-pharyngées infections, and even without any demonstration.
- Serious sometimes: respiratory distress at the time of an obstructive broncho-pneumonopathy involving the hospitalization.
Frequency: 20 to 30% of the atypical respiratory infections.
Pathogenic capacity of the mycoplasmes
Respiratory infections: Mycoplasme pneumoniae
Genital infections : Mycoplasma hominis
Mycoplasme gcnitalium Ureaplasma urealyticum
Character commun runs
- Morphology and structure
. Spherical elements of very small size: 0,1 to 0,3 microns. Deprived of wall. Having ADN and ARN
. Close relations of the bacteria, they belong to the class of Molli eûtes
- Culture
Need for mediums hypertonic nouveau riches géloses or liquids Very small fried egg colonies “”
- Vitality
Very fragile
Bacteriological diagnosis
- Direct: Culture which allows the identification and the study of
in vitro sensitivity to antibiotics: +++ for Mycoplasmes genital
- Indirect:
Sérodiagnostic by reaction of fixing of the complement (R F C) for the respiratory infections with Mycoplasme pneumoniae
Sensitivity to antibiotics
- Sensitive to the tétracyclines and macrolides
- Resistant to bétalactaminés
Respiratory infections with Chlamidia
Respiratory infections with Chlamydia psittaci
It is a ZOONOSE: it touches the animals in general, accidentally the man.
* in the animals, one distinguishes:
. Ornithose transmitted by the pigeon
. the Psittacosis transmitted by the parrot
* at the man: it is seldom touched; however, when it is it, that is serious.
Respiratory infections with Chlamidia trachomatis
It is the 1st cause of pneumopathy at the new one born by contamination during the childbirth.
Respiratory infections with Chlamidia pneumoniae
It is a very frequent infection: 50% of the 30 year old adults have serum antibodies directed against this bacterium.
In general, one assists with: . an atypical pneumopathy very often benign (viral standard)
. or with a pharyngitis/bronchitis
Reinfected are frequent and serious at the immunodé-preceded subjects.
Bacteria
Mycoplasme pneumoniae
Common characters
morpho. - structure: SMALL size and ABSCENCE of WALL => fragile culture: special mediums
Diagnosis
* direct: the bacterium is not highlighted in the expectoration.
* indirect: it is necessary to seek the serum antibodies of the patient in particular by the reaction of fixing of the complement; the study is done on 2 serums taken at 15 days of interval.
3. Sensitivity to antibiotics: sensitive to the tétracyclines and macrolides
Pneumoniae and psittaci
Common characters
Morphology:
structure: very small, comparable with C. trachomatis.
culture: on alive cells; the cycle of reproduction is longer than that of Chlamydia trachomatis, it lasts with the 72h minimum and leads to inclusions will intra cytoplasmic.
Diagnosis = especially sérodiagnostic: description of serum antibodies by:
* R° de Fixation of the Complement -> Thus of Chlamidiose (not very sensitive)
* Immunofluorescence and ELISA thus species
Sensitivity to antibiotics: sensitive to the tétracyclines and macrolides
Chlamidiae
Pathogenic capacity
Respiratory infections:
Chlamydia pneumoniae
Chlamydia psittaci
Genital infections (PUT): Chlamydia trachomatis
- Venereal Lymphogranulomatosis = sérotypes L , L, L
- Genital Infections oculo = sérotypes D with K
Common characters
- Morphology
Very small bacteria (0,3 microns)
- Culture
Need for alive cells:
. Embryonné egg
. Culture of cells
- Vitality
Very fragile bacteria
Bacteriological diagnosis
- Direct:
. Direct examination: Immunofluorescence with monoclonal antibodies
. Seek ADN by PCR
