Differences Between Staphylococcus And Streptococcus

When studying bacteria and other small organisms, you may come across two very similar terms called staphylococcus and streptococcus.

Differences Between Staphylococcus And Streptococcus

Just like with other things that have similar names but are actually very different – such as stalagmite and stalactite in caves – it’s very common for people to mix up the two and forget which one is which. 

If you are struggling to remember the differences between staphylococcus and streptococcus, then here are all the differences laid out for you so you can remember them much more clearly in the future. 


Both staphylococcus and streptococcus have different arrangements although they are both cocci in shape.

Staphylococcus are arranged in clusters that resemble bunches of grapes while streptococci are arranged in a chain, kind of like a conga line. 

A way you can try and remember this difference in the future is through streptococcus’ name. The ‘Strep’ part sounds like ‘step’ as in ‘steps’ in a dance, like a conga line.

This means that Streptococcus must be the one arranged in a chain and by process of elimination, Staphylococcus is the organism that is arranged in clusters. 


These two organisms also divide in different directions. Staphylococcus divides in lots of different directions on multiple axes while Streptococcus divides in a linear line – which is why it is always arranged in a chain. 

Habitat And Disease

Staphylococcus is found on skin while Streptococcus is found inside the respiratory tract instead.

This difference in habitat is one of the main differences between these two organisms because it also affects which diseases they are affected by. 

Staphylococcus is caused by diseases like conjunctivitis, bacterial infections, impetigo, cellulitis, and toxic shock syndrome – common ailments that affect the skin.

Streptococcus instead is caused by more viral infections including strep throat, scarlet fever, pneumonia and meningitis in newborn babies. 

Catalase Test Results

The catalase test  is a test that detects the presence of the catalase enzyme by searching for the decomposition of hydrogen peroxide which in turn releases oxygen and water. In layman’s terms – does it make bubbles? 

Staphylococcus does when it is submerged in water, which means it tests positive in the catalase test and does feature catalase, while Streptococcus does not so it tests negative. 

Species Number 

There are around 40 different species of Staphylococcus that have been identified, while Streptococcus has around 50 different identified species. 

Fastidious Vs Non Fastidious

For a microbial organism to be classed as fastidious, it needs enriched media to grow with the correct nutrients.

Streptococcus needs an enriched media in order to grow, while Staphylococcus does not. This means that Streptococcus is fastidious while Staphylococcus is not. 


Hemolysis is the breakdown of red blood cells, but Streptococcus and Staphylococcus both break down red blood cells differently.

Streptococcus can be an alpha, beta or gamma in hemolysis depending on its species, while Staphylococcus can only be a beta or gamma. 


Those are all the differences between Streptococcus and Staphylococcus. If you are ever in doubt of which is which, just check out the above information when you need it! 

Jennifer Dawkins