Encapsulated Streptococcus pneumoniae

This image is a Gram stain of a sputum specimen from a patient with pneumonia. The Gram stain shows encapsulated lancet-shaped gram-positive cocci associated with the polymorphonuclear leukocytes. Note the clear zone surrounding the organisms. This zone is consistent with a large polysaccharide capsule that is not picked up by the Gram stain. These Gram stain findings are consistent with Streptococcus pneumoniae.

S. pneumoniae is a bacterium that can be found in the lung. This disease can be divided into two forms, lobar pneumonia and bronchial pneumonia. Bronchial pneumonia is prevalent in infants, young children, and older adults. Lobar pneumonia is more likely to occur in young adults. S. pneumoniae is a Gram-positive, lanceolate shaped coccus that is usually seen in pairs of cocci (diplococci