Make AST faster with FAST method for antimicrobial susceptibility testing

FAST method for antimicrobial susceptibility testing

After a long lead-in, the first description of our FAST method has just stepped out of the shadows for all to see. FAST stands for flow-assisted antimicrobial susceptibility testing. It is an ultra-rapid method for one of the species on the World Health Organization’s top priority multidrug resistant bacteria hit list.

The FAST Lab team of bacterial flow cytometrists shortly after the 1st FAST method’s publication.

Introducing the lab team.

The FAST Lab team on the QE2 Medical Campus in Perth, Western Australia have been working on multi-drug resistant Klebsiella for several years now. They have witnessed an increase in carbapenem resistance. The mechanisms of resistance to carbapenems are getting increasingly complicated. This can make the pathology laboratory’s task a bit tricky, prolonging the time it takes to come up with a definitive antimicrobial susceptibility. This rapid method is our response to the challenge. It’s now up to the FAST Lab and our international partner labs to work out how to bring this rapid method into wider use.

See the FAST Lab team here.

The need for a faster AST method.

The FAST scanner. Thinking the task through from the pointy, clinical end, the overriding problem is that the antibiotic pipeline is very dry. It will take a decade or more to bring any major new antibiotic into widespread clinical use. That is why we need better, faster diagnostic methods to target our dwindling stock of antibiotics more effectively. At the moment, conventional antimicrobial susceptibility tests take 18-36 hours after initial detection of bacteria in a clinical sample. The internationally recognised Minimum Inhibitory Concentration (MIC) takes 24hr. MIOC tests start with a pure culture of the bacterial species in question and depend on culture. Our method takes around three hours because it uses an acoustic flow cytometer to detect early changes in antibiotic-exposed bacteria. As a flow cytometer is a very sophisticated automated microscope, you can imagine how much more efficient it is than the human eye.

Speed dating AMR

The race is on. Can FAST get even faster? At present, the first iteration of our method removes the delay caused by the second culture stage in the clinical lab process. True culture-independent antimicrobial susceptibility testing has to remove the primary culture stage as well if the treating physician is going to get antibiotic decision support at the point of care. The time it takes to complete the decision pathway is particularly important in sepsis. We may be fast, but we’re not yet on the inside track with severe drug resistant infections. There are some promising technologies that could lead to practical improvements, but you will have to wait a bit longer for the lab team to bring them to fruition.

Additional information