Detection of Klebsiella pneumoniae Co-Producing KPC-2 and MCR-8 in the Feces of an ICU Patient From China

Abstract

It is critical to acknowledge that the coexistence of genes related to carbapenem and polymyxin resistance can exacerbate challenges in antimicrobial therapy. In this study, we identified Klebsiella pneumoniae isolate L2425 from the feces of an ICU patient in China. The isolate belongs to sequence type 11 and carries the antimicrobial resistance genes bla KPC-2, bla CTX-M-65 and mcr-8. Through S1-nuclease pulsed-field gel electrophoresis and Southern blotting analysis, we confirmed the presence of a ~ 110 kb plasmid harboring the mcr-8 gene with a conserved structure (inhA-mcr-8-ompR-dgkA-IS903B). Furthermore, another ~130 kb plasmid carrying bla KPC-2 was detected along with a composite transposon flanked by insertion sequence IS26. Conjugation experiments demonstrated that both pL2425-KPC-2 and pL2425-MCR-8 plasmids were transferable. Importantly, this is the first instance of clinical fecal samples from China containing a K. pneumoniae strain carrying both bla KPC-2 and mcr-8 genes. These findings underscore the significance of surveillance for carbapenemases and mobile colistin–resistance variants.