Rapid time to results and high sensitivity of the CarbaNP test on early cultures.

For rapid results, we adapted the CarbaNP test by using 5-hour-old cultures; the sensitivity and specificity for detection of carbapenemase production were 100% for non-OXA-producing organisms. The sensitivity from early cultures was 94% for detection of carbapenemase production in Enterobacteriaceae strains. Utilizing younger cultures allows the test to be incorporated into a single day's workflow, facilitating timely patient care and antimicrobial stewardship.