Pneumococcal pneumonia

Abstract

Pneumococcal pneumonia accounts for about one-sixth to two-thirds of all cases of community-acquired pneumonia. Its high frequency of occurrence worldwide and the high number of deaths associated with it--especially with bacteremic (invasive) disease--mark its importance. Invasive disease is associated with case-fatality rates of 15% to 25% among elderly adults. Penicillin-resistant Streptococcus pneumoniae (PRSP) first appeared in the 1970s, and its increased incidence in the late 1980s signaled its emerging importance. In individual patients in whom PRSP infection is suspected, the clinician must follow guidelines for empiric antibiotic therapy for community-acquired pneumonia until microbiological test results are known. When a diagnosis of pneumococcal pneumonia is established, the clinician should change to a regimen that targets the pneumococcus. Adults at highest risk for death from pneumococcal pneumonia include immunocompetent persons with underlying chronic diseases, immunocompromised persons, elderly persons, and unvaccinated residents of nursing homes and other chronic care facilities. Safe and effective, polyvalent polysaccharide pneumococcal vaccine should be used in persons 2 years of age and older who are at increased risk for serious pneumococcal pneumonia and in all persons 65 years of age and older.

Secretory-IgA Antibodies Play an Important Role in the Immunity to Streptococcus pneumoniae

“…We are currently testing functional properties of anti-PspA IgG Abs in nasal secretions. Severity and mortality caused by infectious pathogens invading mucosal surfaces including the bacterial pathogen S. pneumoniae have sharply increased in the elderly (44)(45)(46). Indeed, the pneumococcus is a major human bacterial pathogen and a significant cause of morbidity, resulting in .40,000 deaths in the United States each year (47).…”

Systemic cytokine response in patients with community-acquired pneumonia

“…One reason could be that S. pneumoniae is an extracellular pathogen and causes a more invasive disease [51]. A number of the other causative pathogens are intracellular bacteria and therefore the nature of the cytokine response will differ [52,53].…”

Concerted Action of Lactate Oxidase and Pyruvate Oxidase in Aerobic Growth of Streptococcus pneumoniae : Role of Lactate as an Energy Source

“…(i) As long as glucose is available, approximately one-fourth of the pyruvate formed is converted to acetate by the sequential action of pyruvate oxidase and acetate kinase with acquisition of additional ATP; (ii) the rest of the pyruvate is reduced by lactate dehydrogenase to form lactate, with partial achievement of redox balance; (iii) the lactate is oxidized by lactate oxidase back to pyruvate, which is converted to acetate as described above; and (iv) the sequential reactions mentioned above continue to occur as long as lactate is present. As predicted by this model, exogenously added lactate was shown to increase the final growth yield in the presence of both oxidases.The gram-positive bacterium Streptococcus pneumoniae, also known as pneumococcus, is often a commensal resident of the human upper respiratory tract but also represents an important human pathogen, causing invasive diseases such as pneumonia, otitis media, and meningitis (18,20,22). Recently, a sharp rise in the incidence of drug resistance among clinical isolates of S. pneumoniae has been posing serious problems (13).…”

“…The gram-positive bacterium Streptococcus pneumoniae, also known as pneumococcus, is often a commensal resident of the human upper respiratory tract but also represents an important human pathogen, causing invasive diseases such as pneumonia, otitis media, and meningitis (18,20,22). Recently, a sharp rise in the incidence of drug resistance among clinical isolates of S. pneumoniae has been posing serious problems (13).…”