Ke Ma1,2,3, Yu Feng1,2,3, Lu Liu1,2,3, Zhihong Yao1,2,3, Zhiyong Zong1,2,3,4. 1. Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China. 2. Division of Infectious Diseases, State Key Laboratory of Biotherapy, Chengdu, China. 3. Center for Pathogen Research, West China Hospital, Sichuan University, Chengdu, China. 4. Department of Infection Control, West China Hospital, Sichuan University, Chengdu, China.
Abstract
BACKGROUND: Klebsiella pneumoniae resistant to both carbapenems and colistin imposes severe challenges for management. In this study, we report a cluster of 5 carbapenem-resistant K pneumoniae clinical strains belonging to ST1 and K57 types, 4 of which were also resistant to colistin, from 2 hospitals. METHODS: The 5 strains were subjected to whole-genome sequencing (WGS) using the short-read Illumina HiSeq platform, and 2 strains were also selected for long-read WGS using MinION. Clonal relatedness of the 5 strains was determined based on single-nucleotide polymorphisms (SNPs). Conjugation experiments were performed to obtain self-transmissible plasmids. RESULTS: All 5 strains carried the carbapenemase-encoding gene blaNDM-1, whereas the 4 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, nonself-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 5 strains were likely to have a common origin. CONCLUSIONS: Both the intra- and interhospital transfer of strains carrying mcr-8 and blaNDM-1 were identified, which represents an emerging threat for clinical management and infection control.
BACKGROUND:Klebsiella pneumoniae resistant to both carbapenems and colistin imposes severe challenges for management. In this study, we report a cluster of 5 carbapenem-resistant K pneumoniae clinical strains belonging to ST1 and K57 types, 4 of which were also resistant to colistin, from 2 hospitals. METHODS: The 5 strains were subjected to whole-genome sequencing (WGS) using the short-read Illumina HiSeq platform, and 2 strains were also selected for long-read WGS using MinION. Clonal relatedness of the 5 strains was determined based on single-nucleotide polymorphisms (SNPs). Conjugation experiments were performed to obtain self-transmissible plasmids. RESULTS: All 5 strains carried the carbapenemase-encoding gene blaNDM-1, whereas the 4 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, nonself-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 5 strains were likely to have a common origin. CONCLUSIONS: Both the intra- and interhospital transfer of strains carrying mcr-8 and blaNDM-1 were identified, which represents an emerging threat for clinical management and infection control.
Authors: Tamara Salloum; Balig Panossian; Ibrahim Bitar; Jaroslav Hrabak; George F Araj; Sima Tokajian Journal: Antimicrob Resist Infect Control Date: 2020-06-26 Impact factor: 4.887
Authors: C M Dierikx; A P Meijs; P D Hengeveld; F R M van der Klis; J van Vliet; E F Gijsbers; M Rozwandowicz; A H A M van Hoek; A P A Hendrickx; J Hordijk; E Van Duijkeren Journal: JAC Antimicrob Resist Date: 2022-04-19