What is the Difference Between Enterococcus and Streptococcus?

Enterococcus and Streptococcus are two genera of gram-positive bacteria that belong to the phylum Firmicutes. Both genera include non-spore forming, nonmotile, facultative anaerobes that are spherical in shape. However, there are some key differences between the two:

1. Hemolysis: Enterococcus species are generally nonhemolytic, while Streptococcus species are hemolytic.
2. Oxygen Requirement: Both genera are facultative anaerobes, but some Streptococcus species are obligate anaerobes.
3. Pathogenicity: Streptococcus species are known to cause a wide array of diseases, ranging from minor soft tissue infections to life-threatening sepsis. Important pathogens in this group include Streptococcus pyogenes (group A streptococcus), Streptococcus agalactiae (group B streptococcus), and Streptococcus pneumoniae (pneumococcus). Enterococcus species, on the other hand, are part of the oropharyngeal flora and some species can be found in the gastrointestinal tract. They are relatively avirulent organisms, but they can cause dental caries (S. mutans) and are the most common cause of subacute infective endocarditis.
4. Taxonomy: DNA homology studies have established Enterococcus as a separate genus, distinct from Streptococcus.

Some species of Streptococcus, such as Streptococcus pneumoniae and viridans, are beta-hemolytic, while group A and group B streptococci are usually alpha or gamma-hemolytic. Enterococci, formerly classified as streptococci, have been separated into their own genus based on DNA analysis.

Comparative Table: Enterococcus vs Streptococcus

Here is a table comparing the differences between Enterococcus and Streptococcus:

Both Enterococcus and Streptococcus are Gram-positive bacteria with similar cell shapes and growth habits. They can both cause various types of infections, but they have different patterns of hemolysis and sensitivities to antimicrobials. Additionally, DNA homology studies have established Enterococcus as a separate genus, distinct from Streptococcus.