The human body harbors several species of bacteria, viruses, fungi, and protozoa. The excellent majority of these are commensals, or “normal flora,” defined as organisms that live symbiotically on or inside the human host but rarely cause disease.

Anatomic sites where bacteria are usually discovered include the skin (staphylococci and diphtheroids), oropharynx (streptococci, anaerobes), large intestine (enterococci, enteric bacilli), and vagina (lactobacilli). Determining when an isolate is a component from the typical flora rather than an invasive pathogen may be difficult.

Showing all 15 results