Host-specific differences in the contribution of an extended spectrum β-lactamase (ESBL) IncI1 plasmid to intestinal colonisation by Escherichia coli O104:H4

Research output: Contribution to journalArticlepeer-review


  • Michaela Giles
  • Shaun Cawthraw
  • Manal AbuOun
  • Diana Munera
  • Matthew Waldor
  • Roberto La Ragione
  • Jennifer Ritchie

Colleges, School and Institutes

External organisations

  • Animal and Plant Health Agency
  • Brigham & Womens Hosp
  • Harvard Medical School
  • University of Surrey


To assess stability and contribution of a large extended spectrum β-lactamase (ESBL)-containing IncI1 plasmid to intestinal colonization by Escherichia coli O104:H4 in two different mammalian hosts.
Specific-pathogen-free 3-day old New Zealand White rabbits and conventionally-reared 6-week-old weaned lambs were orally infected with wild-type E. coli O104:H4 or the ESBL-plasmid cured derivative, and the recovery of bacteria in intestinal homogenates and faeces monitored over time.
Carriage of the ESBL plasmid had differing impacts on
E. coli O104:H4 colonisation of the two experimental hosts. The plasmid cured strain was recovered at significantly higher levels than wild type during late-stage colonization of rabbits, but at lower levels than wildtype in sheep. Regardless of the animal host, the ESBL plasmid was stably maintained in virtually all in vivo passaged bacteria that were examined.
These findings suggest that carriage of ESBL plasmids has distinct effects on the host bacterium depending upon the animal species it encounters and demonstrates that, as for E. coli O157:H7, ruminants could represent a potential transmission reservoir.


Original languageEnglish
JournalJournal of Antimicrobial Chemotherapy
Early online date28 Feb 2018
Publication statusE-pub ahead of print - 28 Feb 2018