LCN2 and infection: This is consistent with previous observations that (i) ybt is enriched amongst clinical infection isolates compared to asymptomatic carriage isolates (in the range of >30% vs <10%);22,24,51 (ii) a recent report that ybt+ ST258 have a higher attack rate than ybt- ST258 in colonised patients;26 and (iii) the known mechanism by which yersiniabactin can enhance the potential for extraintestinal infection, by evading Lcn2-mediated host immunity25,52.