Abstract
Klebsiella pneumoniae resistant to both carbapenems and colistin imposes severe challenges for management. Here we report a cluster of five carbapenem-resistant K. pneumoniae clinical strains belonging to ST1 and K57 types, four of which were also resistant to colistin, from two hospitals.
The five strains were subjected to whole genome sequencing (WGS) using the short-read Illumina HiSeq platform and two strains were also selected for long-read WGS using MinION. Clonal relatedness of the five strains was determined based on single nucleotide polymorphisms (SNPs). Conjugation experiments were performed to obtain self-transmissible plasmids.
All five strains carried the carbapenemase-encoding gene blaNDM-1, whereas the four colistin-resistant strains also harbored a new variant of the mcr-8 colistin resistance gene, namely mcr-8.2. Mcr-8.2 differs from Mcr-8.1 by four amino acid substitutions (A51V, A232S, N365Y, and N480K). mcr-8.2 was located on a large, hybrid, non-self-transmissible plasmid containing IncQ, IncR, and IncFII replicons, whereas blaNDM-1 was carried by self-transmissible IncX3 plasmids. Phylogenetic analysis based on SNPs revealed that the five strains were likely to have a common origin.
Both the intra- and inter-hospital transfer of strains carrying mcr-8 and blaNDM-1 were identified, which represents an emerging threat for clinical management and infection control.
The post A cluster of colistin- and carbapenem-resistant Klebsiella pneumoniae carrying blaNDM-1 and mcr-8.2 appeared first on Healthier Environment Living Program.