Escherichia coli ST131: Prevalence, Resistance, and Virulence in Boston vs Minneapolis

Segment Description: Elizabeth Hirsch, PharmD, assistant professor at the University of Minnesota College of Pharmacy, and Mélanie Mahoney, PharmD candidate at the University of Minnesota College of Pharmacy, discuss their poster on Escherichia coli ST131 in Boston vs Minneapolis at ECCMID 2019.

Interview transcript (modified slightly for readability):

Contagion®: What sparked your interest in this topic?

Mélanie Mahoney: Our research is on ST131 E coli, specifically UTIs, so we're interested in ST131 because it's found to be associated with a lot of resistance, specifically fluoroquinolone resistance, so that's why we were specifically interested in this sequence type of E coli.

Contagion®: What were the main findings of your study?

Elizabeth Hirsch: We used 2 isolate sets, 1 collected from patients in Boston, Massachusetts, and 1 collected from patients in Minneapolis, Minnesota, and these 2 isolate sets were collected from roughly the same time period in 2013 and 2014 and so we were collaborating with Jim Johnson, who's an ST131 expert. When we compared the 2 isolate sets...

Mahoney: We found that overall their phylogenetic distribution was pretty similar. We looked at their resistance genes profiles [and] they were pretty similar. One key finding was that the CTX-M27 was found uniquely in the Boston isolates, so none in the Minneapolis set. Also the ESBL prevalence was slightly greater in the Boston isolate set than the Minneapolis set so that's been a new finding. The CTX-M27 has been found in Japan, in Europe, but we've found it now in United States clinical isolates.

Contagion®: To what do you attribute the differences in findings between the 2 cities?

Hirsch: We're not sure entirely what accounts for the difference between the 2 cities, but we hypothesize that, with Boston being on the coast, there may be more international patients who are seen at the hospital where the isolates were collected as opposed to patients seen in Minneapolis maybe from more rural settings in the midwest of the United States. However, we're not exactly sure what accounts for the difference.

Mahoney: Those isolates were also from 2013 and 2014. It's possible that now there might be some of that CTX-M27 in Minneapolis, as well.

Contagion®: What is next in this line of research?

Mahoney: Now we're interested in some of the clinical outcomes associated with this ST131, specifically the H30, possibly the C1-M27 clade infections as well. We'd like to do some studies to see if the ST131-H30 is associated with worse clinical outcomes if it's also associated with increased resistance.

Hirsch: We're also interested in doing a comparison of a more contemporaneous isolate set so collecting more isolates from Minneapolis to see if there have been changes from what we saw in the 2013 isolate set so that's something else that we plan to collect more isolates and see if those have changed over time.

The poster, "Escherichia coli ST131 in Boston versus Minneapolis: prevalence, virulence genes, and antibiotic resistance," was presented Monday, April 15, at ECCMID 2019.