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Overview of antibacterial susceptibility testing

Sarah E Turbett, MD
Virginia M Pierce, MD
Section Editor
Stephen B Calderwood, MD
Deputy Editor
Allyson Bloom, MD


The clinical microbiology laboratory serves as a valuable ally to clinicians in the diagnosis and treatment of infectious diseases. In particular, the isolation of bacteria from clinical samples yields information that can be used to guide the selection of appropriate antibiotic regimens based on knowledge of the most likely susceptibility profile of certain bacterial species. Through the use of in vitro antimicrobial susceptibility testing, the laboratory can specifically determine which antibiotics effectively inhibit the growth of a given bacterial isolate, allowing for targeted therapy. Antimicrobial resistance is a growing concern in both community and health care settings; as such, decisions surrounding empirical antibiotic treatment are becoming more complicated, and the importance of routine antimicrobial susceptibility testing to guide therapeutic decisions has increased.

Multiple different methods for antimicrobial susceptibility testing exist, including conventional methods, automated systems, and newer molecular techniques. Understanding these methods allows clinicians to correctly interpret susceptibility testing results reported by the clinical microbiology laboratory. In general, antimicrobial susceptibility testing methods used in clinical laboratories should:

Provide rapid and accurate information to the clinician

Be relatively inexpensive

Be relatively easy to perform

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Literature review current through: Dec 2017. | This topic last updated: Oct 04, 2017.
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