Fig. 3
blaCTX-M genes present on short chromosomal insertions in E. coli. a Zam_UTH_41. This E. coli ST8767 strain carried blaCTX-M-14 on a 3,095 bp chromosomal insertion with ISEcp1 located 249 bp upstream of blaCTX-M-14. Zam_UTH_26 (not shown) also had a similar genetic context for its insertion. b Zam_UTH_43. This E. coli ST131 O107:H5 strain harbored blaCTX-M-15 on a 6,036 bp chromosomal insertion, with ISEcp1 located 255 bp upstream of blaCTX-M-15. About 2.5 kb downstream of this insertion was another insertion that harbored genes conferring resistance to chloramphenicol (cat), β-lactams (blaOXA-1), and aminoglycosides/quinolones (aac(6′)-Ib-cr5). F1, F2, F3, R1, R2, R3; primers used for confirmation of insertions