Higher prevalence of CTX-M-27-producing Escherichia coli belonging to ST131 clade C1 among residents of two long-term care facilities in Southern Spain.

Recently, the emergence of an international lineage of the CTX-M-27-producing clade C1 of Escherichia coli ST131 is being observed. The aim is to see if this strain has also been introduced in our area. Twenty-eight (33%) out of 86 individuals from two LTCFs in Seville were found to be colonized with fluoroquinolone-resistant E. coli ST131 and 46% isolates were ESBL/pAmpC producers. C1 isolates were more common than C2 and more frequently produced blaESBL/pAmpC genes (53% vs 33%). Strain sharing was observed in 6 groups of 2-5 cases (61%). A differentiated cluster of 5 C1-CTX-M-27 isolates was found which lacked the M27PP1 region.