A Nosocomial Respiratory Infection Outbreak of Carbapenem-ResistantEscherichia coliST131 With Multiple TransmissibleblaKPC-2Carrying Plasmids

Escherichia colisequence type 131 (ST131) is well known for its multidrug resistance profile. Carbapenems have been considered the treatment of choice forE. coliST131 infections, and resistance to carbapenems is emerging due to the acquisition of carbapenemase-encoding genes. In this study, 45 carbapenem-resistantE. colistrains were collected in a hospital. The resistance mechanisms, plasmid profiles, and genetic relatedness of these strains were determined. Phylogenetic relationships between these strains were assessed by molecular profiling and aligned with patient clinical details. The genetic context ofbla(KPC-2)was analyzed to trace the potential dissemination ofbla(KPC-2). The 45 carbapenem-resistantE. coliST131 strains were closely related. Initially prevalent only in a single ward, ST131 subsequently spread to other ward, resulting in a respiratory infection outbreak of carbapenem-resistantE. coliST131. Eight of the 30 patients died within 28 days of the first isolation ofE. coliST131. Thebla(KPC-2)-positive plasmid profiles suggest that the carbapenem resistance was due to the acquisition byE. coliST131 of transmissible plasmids pE0272_KPC and pE0171_KPC carryingbla(KPC-2). Additionally, diverse multidrug resistance elements were transferred and rearranged between these plasmids mediated by IS26. Our research indicates that clinical attention should be paid to the importance ofE. coliST131 in respiratory infections and the spread ofbla(KPC)-carryingE. coliST131.