Streptococcus pneumoniae diseases caused

Streptococcus pneumoniae remains the commonest cause of pneumonia and responds well to penicillin. In addition, a number of atypical infections may cause pneumonia and include Mycoplasma pneumoniae, Legionella pneumophila, psittacosis and occasionally Q fever. With psittacosis there may be a history of contact with parrots or budgerigars while Legionnaires disease has often been acquired during hotel holidays... 

Streptococcus pneumoniae is the most common bacterial cause of community-acquired respiratory tract infections. S. pneumoniae causes approximately 3000 cases of meningitis, 50,000 cases of bacteremia, 500,000 cases of pneumonia, and over 1 million cases of otitis media each year. The increasing prevalence of drug-resistant S. pneumoniae has highlighted the need to prevent infection through vaccination. Both licensed pneumococcal vaccines are highly effective in preventing disease from the common S. pneumoniae serotypes that cause human disease. 

Mescher and many others suspected that nuclein (nucleic acid) was associated in some way with cell inheritance, but the first direct evidence that DNA is the bearer of genetic information came in 1944 through a discovery made by Oswald T. Avery, Colin MacLeod, and Maclyn McCarty. These investigators found that DNA extracted from a virulent (disease-causing) strain of the bacterium Streptococcus pneumoniae, also known as pneumococcus, genetically transformed a nonvirulent strain of this organism into a virulent form (Fig. 8-12). 

Qll Acute exacerbations of chronic bronchitis can be caused either by viral or bacterial infections. Production of thick, green sputum suggests Chandra has a bacterial infection. Common bacterial pathogens affecting the lung include Streptococcus pneumoniae and Haemophilus influenzae. It is recommended that COPD patients receive influenza vaccine each year pneumoccocal vaccine is also often recommended in chronic lung disease and may prevent recurrence of chest infection in the elderly. 

Disease that is segmental or lobar in its distribution is usually caused by Streptococcus pneumoniae (pneumococcus). Haemophilus influenzae is a rare cause in this group, although it more often leads to exacerbations of chronic bronchitis and does cause pneumonia in patients infected with HIV. Benzyl-penicillin i.v. or amoxicillin p.o. are the treatments of choice if pneumococcal pneumonia is very likely alternatively, use erythromycin/clarithromycin in a penicillin-allergic patient. Seriously ill patients are best given benzylpenicillin (to cover the pneumococcus) plus ciprofloxacin (to cover Haemophilus and atypical pathogens). Where penicillin-resistant pneumococci are prevalent, i.v. cefotaxime is a reasonable best guess choice. 

Azithromycin, an azalide macrolide antibiotic (500 mg p.o. as a single dose on day 1, followed by 250 mg daily on days 2 to 5 total accumulation dose is 1.5 g), is indicated in the treatment of acute bacterial exacerbations of chronic obstructive pulmonary disease caused by Haemophilus influenzae, Moraxella (Branhamella) catarrhalis, or Streptococcus pneumoniae mild community-acquired pneumonia caused by H. influenzae or S. pneumoniae uncomplicated skin and skin-structure infections caused by Staphylococcus aureus, Streptococcus pyogenes, or S. agalactiae second-line therapy of pharyngitis or tonsillitis caused by S. pyogenes and in nongonococcal urethritis or cervicitis caused by Chlamydia trachomatis. 

Not all bacteria are pathogenic or harmful to humans. Some microorganisms are harmless or even some are very useful for human beings. An example is the lactobacilli in human stomach that helps in converting lactose and other sugars to lactic acid. However, these bacteria will cause disease if they are detected in environments that are not their normal habitat. Thus, the presence of certain bacteria out of their normal habitat is an indicator of a certain disease or contamination. For example. Enterococcus species is used as an indicator of fecal pollution in environmental waters, while the detection of species-specific Enterococcus faeciutn is used as an indicator of human fecal pollution [13]. On the other hand, the presence of some bacteria almost certainly indicate an infection for example, Mycobacterium tuberculosis causes tuberculosis, and Streptococcus and Pseudomonas cause pneumonia. 

This vaccine is indicated for immunization of infants and toddlers against disease caused by Streptococcus pneumoniae due to capsular serotypes included in the vaccine (4, 6B, 9V, 14, 18C, 19F, and 23F). S. pneumoniae causes invasive infections such as bacteremia, meningitis, pneumonia, and upper respiratory infections including otitis media and sinusitis [16], Table 8 [14] lists the IgG and IgM mouse antibody responses for types 9V, 14, 18C,... 

The important role of anti-polysaccharide antibodies in protection from diseases caused by encapsulated bacteria was demonstrated in the seventies for Haemophilus influenzae type b. Neisseria meningitides and Streptococcus pneumoniae. 

According to the time of diagnosis, VAP can be subdivided into early-onset (diagnosed within the first 4 days of ventilation) and late-onset disease (diagnosed after more than 4 days of ventilation) (11). Early-onset VAP is usually caused by community-acquired bacteria colonizing the upper respiratory tract before hospital admission (e.g.. Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus), these are presumably aspirated... 

Atmospheric particle concentrations have been linked with hospital admissions for pneumonia among the elderly (41). Pneumonia is a common complication of COPD, and it is often the precipitating terminal event. An increase in the incidence of pneumonia would thus be consistent with adverse effects on patients with COPD or other chronic respiratory diseases. All of the host defense factors listed in the foregoing for COPD could be important in particle effects on the risk of developing pneumonia interference with host defense mechanisms would be expected to increase this common cause of respiratory morbidity and mortality. Data are lacking that would allow assessment of particle effects on defense against specific pathogens important in humans, such as Streptococcus pneumoniae. 

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