How much normal flora is associated with the human body? Where is it located? When is it acquired?
- ~1014 bacteria associated with the ~1013 body cells (the majority in the large bowel)
- Viruses, fungi, and protozoa form only a minor component
- Internal organs and tissues are normally sterile
- Acquired rapidly during and shortly after birth
- Continuously changes throughout life
- Normal flora occur in parts that are exposed to the environment (skin, nose, mouth, intestinal tract, urinogenital tract)