Rapid impedance-based Antimicrobial Susceptibility Testing (iFAST) of Enterobacterales in urinary tract infections
Classical MIC testing for antimicrobial susceptibility can be time-consuming with results taken up to 48 hrs with culture. This study evaluates the use of a reagent free technology termed impedance-based Fast Antimicrobial Susceptibility Test (iFAST) as a more rapid alternative to broth based MIC testing. The technology works by measuring the change in impedance across the bacterial membrane following antibiotic exposure. A panel of 58 Escherichia coli and Klebsiella pneumoniae strains were exposed to antibiotics commonly used to treat urinary tract infections (UTI's) at concentrations defined by EUCAST breakpoints. Following a 2-hour exposure to the antibiotic, results showed a high level of correlation with those obtained by broth microdilution MIC testing. These results show the potential of a rapid susceptibility test, with results obtained in less than five hours, to help support and speed up decision making for effective treatment of UTI's.