Antimicrobial Susceptibility Monitoring

Use of antimicrobics has increased in both human and veterinary. Although use may result in a portion of bacteria that are resistant, the exact fate of this population in terms of persistence and transmission has been difficult to determine. Additionally, while transmission of resistant bacteria from animals to humans occurs, it has been difficult to assess the extent to which this occurs. To track emerging resistance, the National Antimicrobial Resistance Monitoring System-Enteric Bacteria (NARMS) was established for both human and veterinary pathogens. Salmonella was chosen as the sentinel organism. Campylobacter (animal isolates starting in 1998) and E. coli 0157:H7 (when available) are also tested. Testing for the Salmonella and E. coli isolates is conducted using a semi-automated system (SensititreTM, TREK Diagnostics). Plates are custom made with 17 antimicrobics in an MIC format. Campylobacter testing is done using the E-test (AB BIODISK). Results from this program will facilitate the identification of resistance in humans and animals as it arises, provide descriptive data on the extent and temporal trends of antimicrobial susceptibility, provide timely information to veterinarians and physicians, prolong the lifespan of approved drugs by promoting the prudent and judicious use of antimicrobics, and identify areas for more detailed investigation.