What is The Current Process for Clearance of Antimicrobial Susceptibility Testing in the US?

Romney Humphries, PhD, D(ABMM), section chief of Clinical Microbiology at the University of California, Los Angeles, sat down with Contagion^® to discuss the process for receiving clearance on antimicrobial susceptibility tests in the United States.

Interview Transcript (slightly modified for readability):

“In the United States, the process for clearing an antimicrobial susceptibility test includes submission of, typically, a 510(k) clearance to the US Food and Drug Administration (FDA). What that entails is a set of studies that are done to show that the test is accurate as compared to a reference standard. What we use as the reference standard is the CLSI Broth Microdilution Susceptibility Method. What happens is, at 3 different sites, they test a number of isolates that are resistant and susceptible to the given antibiotic and compare [the results] to the reference broth microdilution and make sure that they get the same results, within a certain margin of error.

Some of the challenges associated with this is that the FDA is very strict, both on the process by which this is done, as well as which drug-bug combinations they will approve. For example, if a given organism isn’t listed in the ‘Indications for Use’ for an antibiotic, it [might] not get cleared through the FDA as a susceptibility test. The FDA does not want to promote ‘off-label’ use of antibiotics. However, we know that in the United States, as well as across the world, people use antibiotics all the time off-label, both for difficult infections as well as organisms that we don’t typically see in clinical trials, for example with Acinetobacter baumannii.”