Dangerous bacteria are microorganisms that can cause serious illnesses and even death. Staph, or Staphylococcus aureus, is a type of bacteria that can cause skin infections, pneumonia, and food poisoning. GERMS, or microorganisms, are microscopic organisms that can cause disease. E. coli, or Escherichia coli, is a type of bacteria that can cause diarrhea, urinary tract infections, and other illnesses. All three of these dangerous bacteria can be spread through contact with an infected person or contaminated food or water.