Pitfalls Associated With Antibiograms

An accurate, appropriately collated antibiogram represents an integral resource for health care providers when assessing bacterial resistance and guiding antimicrobial selection and formulary decisions. Interpretation of bacterial susceptibility statistics is problematic yet frequent and unrecognized pitfalls may be avoided by following the M39-A2 guidelines to ensure correct analysis and presentation of cumulative antimicrobial susceptibility test data. This review addresses guideline recommendations related to antibiogram development, CLSI breakpoint interpretation, antimicrobial inclusion decisions, and the avoidance of duplicate and surveillance isolates. Unit-specific antibiograms in critical care units is encouraged for differentiation between hospital-wide ecology and these specific areas harboring more resistant pathogens. Antibiograms cannot track the emergence of microbial resistance during therapy and discrepancies exist between automated microbiology surveillance systems and their agreement with manual surveillance methods. When striving to improve overall patient outcomes, the use of a well-produced and disseminated antibiogram helps guide clinical decision making for patients requiring antimicrobial therapy.