pCESC3 was identified as an A/C plasmid by replicon typing (Moran
et al., 2015) of a collection of commensal E. coli strains (Bailey et al.,
2010). The replicon was sequenced and confirmed that pCESC3 is an
IncC (A/C2) plasmid. The strain carrying pCESC3, 21.1-S1, was susceptible
to all antibiotics tested, suggesting that pCESC3 could represent an
ancestral IncC plasmid that existed prior to the acquisition of antibiotic
resistance islands.