Aerobic and Facultatively Anaerobic Bacteria

Abstract

Bacteria are identified whenever their presence is considered clinically significant. Isolates, therefore, from normally sterile sites require identification and antimicrobial susceptibility testing. Those without recognized clinical importance from sites normally harboring indigenous flora (Table 1–1) seldom require identification. Indeed, reporting normal flora may be highly misleading since specific identification by the laboratory would generally appear to ascribe clinical importance to any organisms reported. For this reason, reports of throat cultures can usually be limited to whether or not group A streptococci are present, and reports of stool cultures can be limited to whether or not recognized enteric pathogens are present. No useful purpose is served by identifying and reporting organisms indigenous to the oropharynx or gastrointestinal tract, despite the fact that their isolation from other sites may be clinically significant. By the same token, when cultures fail to yield recognized pathogens, the report should clearly state that cultures were negative for the specific pathogens sought (e.g., Salmonella, Shigella, Yersinia, and Campylobacter jejuni in feces) rather than simply to report the cultures were negative.