What is a key characteristic of staphylococci bacteria?

A key characteristic of staphylococci bacteria is that they grow in clusters like grapes. This distinctive arrangement is due to the way the bacteria divide; they undergo binary fission and remain clumped together rather than separating after dividing. This clustering can be visually identified under a microscope, which can differentiate staphylococci from other bacterial types.

While some strains of staphylococci are usually harmless and can inhabit human skin and mucous membranes, this is not a defining trait of the bacteria themselves. They are known for their ability to cause infections, not for thriving only in specific environments, nor can it be stated that they cause no infections in humans—many strains, such as Staphylococcus aureus, are pathogenic and can lead to serious health issues. Therefore, the characteristic of clustering in groups is the most defining aspect of staphylococci.