Keywords: Mycoplasma pneumonia

    Etiology

    Mycoplasma pneumoniae is between between bacteria and viruses the smallest microorganism that can live independently, the size of 200 nm. No cell wall, only the composition of the cell membrane by a three-layer film, often confused with the bacterial L-type phase, colonies of the two similar, can be grown on a cell-free culture medium and splitting reproduction containing RNA and DNA to generate energy through metabolism sensitive to antibiotics. Mycoplasma for animals to many kinds of diseases body has been found eight types, of which only the Mycoplasma pneumoniae certainly human pathogenic respiratory disease. Good growth in 20% horse serum and yeast agar medium, the initial culture in the visible under a microscope typical circular roof-shaped mulberry-like colonies, after several passages forwarded omelette shape. Mycoplasma fermentation of glucose, has the role of blood adsorption (hemadsorption), dissolved in guinea pigs, sheep red blood cells, with methylene blue, thallium acetate, penicillin resistance. Last yet for serum identified. By mouth, nasal secretions spread by air, caused by the dissemination and prevalence of respiratory infections, mainly seen in children and adolescents, are not uncommon in adults, autumn and winter more. Respiratory infections pharyngitis and bronchitis, a few involving the lung. 10% of mycoplasma pneumonia accounted for more than 1/3 of bacterial pneumonia, or pneumonia.

    Pathogenesis

    Mycoplasma pneumoniae in 2 to 3 days prior to the onset until the illness is over a few weeks, can be found in the respiratory secretions. By contact with infected, length between the ciliated epithelium, does not invade the lung parenchyma, neuraminic acid receptors on their cell membranes, can be adsorbed on the surface of the airway epithelial cells of the host inhibit ciliary activity and destruction of epithelial cells, while generating hydrogen peroxide further cause local tissue damage. Its pathogenicity may be associated with allergic reactions to pathogens or their metabolites. Infection caused by humoral immunity, already exist in most adult serum antibodies, so there is little incidence.

    Pathological changes

    The lung lesions were flake or confluent bronchopneumonia or interstitial pneumonia with acute bronchitis. The alveoli may contain a small amount of exudate can occur multifocal atelectasis, pulmonary consolidation and emphysema. Alveolar wall and spacing of neutrophils and mononuclear cell infiltration. Bronchial mucosa cells necrosis and shedding, and neutrophil infiltration. The pleura can have fibrin and a small amount of exudate.