Introduction Normal flora login to view 13 more bullets Normal Bacterial Flora Site Predominant Bacteria Skin Staphylococcus epidermidis Staphylococcus aureus Propionibacterium acnes Nose Staphylococcus epidermidis Staphylococcus aureus (in some people) Oropharynx Anaerobes Viridans group Streptococcus Streptococcus mutans (grows on biofilms on teeth) Gastrointestinal tract Helicobacter pylori Anaerobes Bacteroides Escherichia coli Urogenital tract Staphylococcus saprophyticus Escherichia coli Group B streptococcus (Streptococcus agalactiae) Lactobacillus