What is the Difference Between Streptococcus Pneumoniae and Diplococcus Pneumoniae?

The key difference between Streptococcus pneumoniae and Diplococcus pneumoniae lies in their morphology and cell arrangement. Both are Gram-positive, capsule-forming, α-hemolytic cocci that are catalase-negative. They are commonly found in the respiratory tract and can cause pneumonia. Here are the main differences:

• Morphology: Streptococcus pneumoniae exists as chains of paired cocci cells, while Diplococcus pneumoniae exists as pairs of cocci.
• Naming: The organism was initially termed Diplococcus pneumoniae in 1920 due to its characteristic appearance in Gram-stained sputum. It was later renamed Streptococcus pneumoniae in 1974 because it was very similar to streptococci.

Both Streptococcus pneumoniae and Diplococcus pneumoniae can cause pneumonia, an acute respiratory disease that affects the lungs. In healthy individuals, these bacteria may reside asymptomatically in the sinuses and nasal cavity. However, in susceptible individuals with weaker immune systems, such as the elderly and young children, the bacterium may become pathogenic and spread to other locations to cause disease.

Comparative Table: Streptococcus Pneumoniae vs Diplococcus Pneumoniae

Here is a table comparing the differences between Streptococcus pneumoniae and Diplococcus pneumoniae:

Both Streptococcus pneumoniae and Diplococcus pneumoniae are Gram-positive bacteria that commonly reside in the respiratory tract. Streptococcus pneumoniae is known to cause pneumonia and otitis media infections. Diplococcus pneumoniae, on the other hand, is less well-characterized in terms of its infectious potential. The key difference between these two bacteria is their morphology: Streptococcus pneumoniae forms chains of paired cocci cells, while Diplococcus pneumoniae consists of pairs of cocci.