Amy Mathers
Infectious disease physician and professor of medicine and pathology at the University of Virginia; co-chair of the CLSI Antimicrobial Susceptibility Testing Subcommittee and associate director of clinical microbiology.
2
APPEARANCES
2
PODCASTS
Sep 12, 2026
Flora LichtmanHOST
Have we measured that, you know, at how much bacteria you lose after seven days versus 14 days?
Amy MathersGUEST
So some of that research is emerging, and depending on the antibiotic and the situation, um, not all of that's been filled out completely, but there is a dose effect.
Amy MathersGUEST
And some scientists have shown the longer you're on an antibiotic or the more broad-spectrum the antibiotic, that may have a different impact on your gut flora.
Amy MathersGUEST
So some antibiotics that might be more targeted won't cause as much selection for resistance as other antibiotics, and the duration, we know, makes a difference.
Amy MathersGUEST
It also can select for other infections such as C. diff, which may be a, a microbe that you select for when you kill everything else off.
Amy MathersGUEST
C. diff is, is left behind and can cause a gut infection because your normal flora is not there taking up the nutrients.
Amy MathersGUEST
C. diff has a chance to get a foothold in and overgrow and then cause a, a bad colon infection.
Flora LichtmanHOST
I mean, do we have a sense of what the Goldilocks zone is for different antibiotics and different infections?
Amy MathersGUEST
CLSI is a standards development organization, much like UCAST, and it has a large footprint in lab medicine as a standard development organization, even though we're going to just talk about susceptibility testing today.
Amy MathersGUEST
CLSI writ large is a volunteer-led organization, so we don't get paid for all the work that we do.
Amy MathersGUEST
And on that note, we're always looking for more volunteers that are interested in helping us set breakpoints.
Amy MathersGUEST
And I would say that we are looking to do stuff for the United States, but also internationally.
7 MINS LATER
