Culture is microbial growth on or in a nutritional solid or liquid medium; increased numbers of organisms simplify identification. Culture also facilitates testing of antimicrobial susceptibility.
Communication with the laboratory is essential. Although most specimens are placed on general purpose media (eg, blood or chocolate agar), some pathogens require inclusion of specific nutrients and inhibitors (see table Selective Media for Isolation of Common Bacteria) or other special conditions for incubation (eg, a specific temperature, oxygen or carbon dioxide concentration, or duration). If one of these more fastidious pathogens is suspected or if the patient has been taking antimicrobials, the laboratory should be advised. The specimen’s source is reported so that the laboratory can differentiate pathogens from site-specific normal flora.