Two Multidrug-Resistant Escherichia coli Isolates from Blood Cultures After Cervical Conization in a Patient with...

Patients undergoing cervical conization for cervical intraepithelial neoplasia grade II (CIN II) may develop postoperative bloodstream infections (BSIs), and multidrug-resistant (MDR) Escherichia coli isolates with distinct resistance profiles can complicate antimicrobial management. In this case-based study, two E. coli strains, HBFY-1 and HBFY-2, were recovered from blood cultures obtained from a 38-year-old CIN II patient with postoperative fever. The isolates were characterized by antimicrobial susceptibility testing, whole-genome sequencing, conjugation assays, and comparative genomics against publicly available genomes matched by sequence type and serotype. Fever occurred on postoperative day 2. HBFY-1 was fluoroquinolone-resistant; belonged to ST744/O101:H9; carried the extended-spectrum β-lactamase (ESBL) gene bla_CTX-M-27; was phenotypically confirmed as an ESBL producer; and grouped within a multi-source near-neighbor clade consistent with a conserved fluoroquinolone-associated resistance backbone in ST744/O101:H9. HBFY-2 was carbapenem-resistant; belonged to ST48/O113:H32; carried bla_NDM-5 on an IncY-associated plasmid bin; was phenotypically confirmed as a metallo-carbapenemase producer; and did not harbor any ESBL gene. Within the matched ST48/O113:H32 dataset, bla_NDM-5 was detected only in HBFY-2, which clustered within an Asia-enriched lineage, including China-derived human and swine genomes. The bla_CTX-M-27-associated and bla_NDM-5-associated elements were transferred to E. coli C600 at frequencies of 5.3 × 10^-2 and 4.6 × 10^-6, respectively, and transfer of the bla_NDM-5-associated element imposed no detectable growth penalty under the tested conditions. As this study is based on a single clinical case, the findings should be interpreted cautiously, yet they still highlight the potential value of integrating susceptibility testing with rapid genomic characterization for identifying mobilizable carbapenem-resistance platforms.