A Study of Regional Antibiograms in Hampton Roads, Virginia to Evaluate and Monitor Antimicrobial Resistance

Background: Most antimicrobial drug prescriptions in communities are provided by primary care physicians, and national resources on antimicrobial resistance often are not used.

Methods: We studied recent antibiograms from 12 hospitals in the Hampton Roads area, Virginia that refer patients to Sentara Norfolk General Hospital (SNGH), a tertiary-care teaching facility. We combined the data into a regional antibiogram and compared sensitivity rates of common isolates from SNGH to referring hospitals grouped by locale. The incidence of multidrug resistance was determined based on National Healthcare Safety Network (NHSN) definitions. The results were discussed in various forums including medical staff meetings and shared with all participants.

Results: The most common isolate tested was Staphylococcus aureus and the next commonest was Eschericia coli. 53% of S. aureus was oxacillin-resistant, and all tested isolates were susceptible to vancomycin. There was a broad scatter of minimum inhibitory concentration (MIC) of vancomycin within the susceptibility range, and MIC of 4 μg/mL was reported in the year 2012. Meropenem and amikacin were the most active antimicrobials for E. coli. Most variation in antimicrobial susceptibility was noted amongst isolates of Acinetobacter baumannii. The unequal number of isolates tested and the variability in methodology, interpretation and reporting may have contributed to variation.

Conclusion: A regional antibiogram based on referral patterns among hospitals is a useful tool to evaluate and to monitor antimicrobial resistance. A regional-level task force and cooperation among hospital microbiology laboratories will result in standardization of methods and optimal interpretation. Annual updates of the regional antibiogram will allow tracking of resistance and will facilitate antimicrobial management, including patients transferred with HAIs. Incorporation of local microbiology results and resistance patterns into clinical pathways is among the Grade A recommendations in the IDSA/SHEA guidelines for institutional programs to enhance antimicrobial stewardship. Partnership among local institutions and health systems resulting in reduction of antimicrobial resistance can benefit multiple hospitals, their patients, and the community.