Cocci

Bacteria with a round shape are called cocci (from the Greek Kokkos, which marked the fruits such as blueberry). Bacterial cells can be grouped into clusters, which are characteristic for different types of bacteria. The connection of individual bacterial cells in these units is however relatively free and cells can exist independently. The specific shapes of these clusters depend on the method how bacterial cells divide. There are therefore diplococci such as Neisseria gonorrhoeae, which causes the venereal disease gonorrhea. Some of this group of bacteria can be found on human skin. For example it can be staphylococci such as Staphylococcus aureus or tetrads such as Micrococcus Iuteus. They are usually harmless for a healthy person. Under certain circumstances, however, they can cause inflammation of the skin or even pneumonia. Similarly, streptococcus such as Streptococcus pyogenes can cause for example skin infections or a larynx inflammations. Bacterium shaped Sarcina can be for instance Sarcina ventriculi, the bacteria commonly found in soil and harmless to humans.