Final answer:
Staphylococcus and streptococci can be differentiated mainly by the catalase test, where staphylococci are catalase-positive and streptococci are catalase-negative. Additionally, their distinct cell arrangements, such as grape-like clusters for Staphylococcus and chain formations for streptococci, can aid in identification.
Step-by-step explanation:
Staphylococcus can be differentiated from streptococci on the basis of several laboratory tests. The key distinguishing factor is the catalase test. Staphylococcus species are catalase-positive, meaning they produce the enzyme catalase, which breaks down hydrogen peroxide. On the other hand, streptococci do not produce catalase and are thus catalase-negative.
Another distinction involves the microscopic arrangement of the bacteria. Staphylococcus bacteria typically display a grape-like cluster formation, whereas streptococci are known for their chain-forming cocci structure. Both of these genera are gram-positive, which means they stain dark blue or violet by the Gram stain method, so Gram stain reaction alone cannot be used to differentiate them.
In addition to these tests, other biochemical assays can be carried out to further identify and differentiate between various species within these genera, by assessing their metabolic activities and the substances they can ferment.