Clinical Outcome Studies Urged to Evaluate Antimicrobial Susceptibility Detection Tools

The ideal technology can be used at the bedside, produces highly accurate results within 30 minutes, and can detect both resistance and susceptibility.

BOSTON – There are several new and exciting technologies for detecting antimicrobial susceptibility and resistance either under development or making their way into laboratories, said UCLA professor Romney M. Humphries, PhD. But, she added, these new techniques and tools need to be evaluated in clinical trials and should undergo outcomes testing to justify their added cost.

Dr. Humphries, assistant professor and section chief of Clinical Microbiology in the Department of Pathology and Laboratory Medicine at the David Geffen School of Medicine, gave her remarks Friday at ASM Microbe 2016.

The ideal technology, she said, can be used at the bedside, produces highly accurate results within 30 minutes, and can detect both resistance and susceptibility.

“Importantly, because these technologies will be done in the lab, they really should be higher throughput and low complexity. This is one of the challenges we’re facing right now,” she said. “Most of the new technologies are one isolate at a time. At my lab, when we show up in the morning, we can have 20 positive blood cultures. How do you pick which of those 20 which gets to go on the instrument first?”

She added that these new technologies must replace current tools or they have no reason to exist. “It’s very difficult to justify added expense for testing,” she said.“If it’s just another added-on cost, it’s very difficult to justify, not only to hospital administration, but also to your really overworked technologists in the lab.”

Dr. Humphries delivered an overview of the strengths and weaknesses of 5 technologies currently in development: multiplexed automated digital microscopy from Accelerate Diagnostics, GeneWeave/Roche’s pathogen-specific bioparticles, laser light scattering from BacterioScan, microbial weighing from LifeScale Technologies, and the CLSI rapid disk diffusion method. Dr. Humphries presented preliminary data on each method, but added that each need to be evaluated in a randomized, controlled trial to demonstrate efficacy. The lack of such trials has been an ongoing challenge, she said.

“These new technologies are very expensive,” she said. “What we really need are clinical outcomes studies to justify the value of these technologies. Unfortunately, even when we have molecular tests for quite some time, there are very few outcomes studies that are not observational/retrospective.”


  1. Humphries RM, et al. New Technologies for Detecting Susceptibility and Resistance. Presented at the American Society for Microbiology Microbe 2016; June 16-20, 2016; Boston, MA.