The prompt initiation of antibiotics to treat infections has been proven to reduce morbidity and save lives.  However, up to 50% of all antibiotics prescribed in acute care hospitals are either unnecessary or inappropriate.  Antibiotics have potential serious side effects, including adverse drug reactions and Clostridium difficile infection.  In addition, antimicrobial resistance can emerge from the inappropriate use of antibiotics leading to increased morbidity, mortality, and costs of health care. Prevention of the emergence of resistance and the dissemination of resistant microorganisms has the potential to reduce these adverse effects and their associated costs.

The appropriate use of antimicrobials is an essential part of patient safety and an effective antimicrobial stewardship program can limit the emergence and transmission of antimicrobial-resistant bacteria.  In addition, antimicrobial stewardship can reduce health care costs without adversely impacting quality of care.  This lecture will discuss different facets of an antimicrobial stewardship team as well as the role of the microbiology laboratory in the team.  Practical examples of the impact of microbiology on antimicrobial stewardship, using blood cultures as an example, will be provided.