coccus (plural - cocci) are any spherical or near spherical bacteria. When they are formed in pairs they are known as diplococcus , in beadlike chains as streptococcus, in grapelike clusters as staphylococcus, and in groups of eight as (sarcina )

Some diseases that can be caused by coccus-type bacteria: staphylococci infections, food poisoning, urinary tract infections, toxic shock syndrome, meningitis, gonorrhea, throat infection s, pneumonia, and sinusitis.