Associations of molecular types, virulence-gene profiles and virulence patterns in the murine sepsis model of the 23 ST131 E. coli isolates studied.

aVirotypes (including new assigned E) and subtypes of virotype D.bNumber of mice dead within 24 h postinjection. Isolates were classified as rapidly lethal if ≥80% of mice challenged with them died within 24 h postinjection.cNumber of mice dead within 25–48 h postinjection.dTotal number of mice dead within 7 days of experiment.eTotal number of mice dead within 7 days of experiment (final lethality) plus number of mice with local presence of lesion (acute inflammation in the region of bacterial inoculation) when euthanatized.fVirulence-gene profile obtained by PCR for detection of 40 ExPEC-associated virulence genes.gVirulence-gene (VG) score calculated as the sum of all virulence genes detected in an isolate.hExPEC status defined as presence ≥2 of papEF, sfa/focDE, afa/draBC, iutA and kpsM II.iIsolates FV 9873, FV 7563 and H1659 exhibited afa operon FM955459.