Yes, this is O157:H7, not ExPEC. Bully for you. One thing
regarding popular accounts of antibiotic resistance I’ve noticed
is that there is an overemphasis on the evolution of resistance,
and an underemphasis on the spread of resistant bacteria. While
the evolution of resistance is important, most of what we see in
a hospital is not the de novo change of a sensitive strain into
a resistant one (i.e., evolution), but, instead, the survival
and spread of already resistant bacteria in this antibiotic-
laden environment. What this means is that changes in the
frequency of resistant organisms, for better or for worse,
depend not only on antibiotic use, but also on other ecological
dynamics–that is, because of clonal spread. In other words, a
resistant strain might not become more common because it is
resistant, but because it does something else better than most
other strains (e.g., it might be hard for the immune system to
recognize and attack it). A recent paper about antibiotic
resistance in E. coli that cause u