Bacteria, just like sperm cells, have flagella which assist in movement. But, sperm cells only have one flagellum, whereas bacteria contain flagella at several locations throughout their body surface. Although most bacteria are not harmful, a small fraction of them are responsible for many diseases. These bacterial pathogens have affected humans throughout history. Also, such a disease as tuberculosis, a disease responsible for the lives of many, is caused by bacterial pathogens ingested into the body.
Bacteria affect everyone in their daily life because they are found nearly everywhere.
They are found in the air, in food, in living things, in non-living things, and on every imaginable surface. Escherichia coli is a disease causing gram-negative bacillus. These bacteria are commonly found within the intestines of humans as well as other vertebrates. This widely spread bacteria is known to cause urinary tract infections as well as diarrhea. Microcococcus Luteus are gram-positive parasitic spherical bacteria which usually grows in grapelike clusters.