Divergence of affinities, serotypes and virulence factor between CTX-M Escherichia coli and non-CTX-M producers.

This study was undertaken to discern the differences of the multi-locus sequence typing (MLST), O serogroups, and virulence factors among 34 CTX-M-1 Escherichia coli, 49 CTX-M-9 strains and 23 non-CTX-M isolates from chickens in Henan province, China. The MLST scheme yielded 34 sequence types, in which ST155 and ST359 were frequent (17% and 15%, respectively) and associated with zoonotic disease. The irp-2 (20% versus 2%, P = 0.

Complete Sequence of pEC012, a Multidrug-Resistant IncI1 ST71 Plasmid Carrying bla CTX-M-65, rmtB, fosA3, floR, and oqxAB in an Avian Escherichia coli ST117 Strain.

A 139,622-bp IncI1 ST71 conjugative plasmid pEC012 from an avian Escherichia coli D-ST117 strain was sequenced, which carried five IS26-bracketed resistance modules: IS26-fosA3-orf1-orf2-Δorf3-IS26, IS26-fip-ΔISEcp1-bla CTX-M-65-IS903D-iroN-IS26, IS26-ΔtnpR-bla TEM-1-rmtB-IS26, IS26-oqxAB-IS26, and IS26-floR-aac(3)-IV-IS26. The backbone of pEC012 was similar to that of several other IncI1 ST71 plasmids: pV408, pM105, and pC271, but these plasmids had different arrangements of multidrug resistance region. In addition, the novel ISEc57 element was identified, which is in the IS21 family.