Реферат «Роль пневмококів у респіраторних захворюваннях молодняка»З предмету Іноземні мови · додано 06.05.2014 17:36 · від Juliettus · Додати в закладки
Streptococcus pneumoniae (the pneumococcus) is the classic example of a highly invasive, Gram-positive, extracellular bacterial pathogen. It is a major cause of morbidity and mortality globally causing more deaths than any other infectious disease. Pneumococcal diseases range from mild respiratory tract mucosal infections such as otitis media and sinusitis to more severe diseases such as pneumonia, septicemia, and meningitis.
Medically, the three major bacterial pathogens of young animals have historically been the pneumococcus, Haemophilus, and meningococcus. All three are naturally transformable and undergo autolysis in the stationary phase. They share the same progression of disease from the nasopharynx to blood and brain and use phosphorylcholine on their surfaces to bind to the same series of receptors in the pathway of innate invasion (Thornton et al. 2010). This uniquely shared pattern of disease and microbial biology makes understanding this group of enormous importance.
Haemophilus and meningococcus, pneumococcus remains a poorly controlled outlier. The huge number of pneumococcal serotypes (compared to the small number for the other two pathogens) remains the main challenge in developing strategies to control this global pathogen.
Pneumococcal serotypes causing invasive disease have been shown to differ between geographic areas and the distribution is also dependent on the time period studied. This is especially important because current pneumococcal vaccines are based on a limited number of capsular polysaccharides.