File:Staph.jpg

Bacterial cells of the bacteria (Staphylococcus aureus) which is one of the causal agents of mastitis in dairy cows. Its large capsule protects the organism from attack by the cow’s immunological defenses.

Source:USDA, ARS, EMU. "All of the micrographs on the web site are in the public domain and can be freely used."

http://emu.arsusda.gov/typesof/pages/staph.html