Molecular Mechanisms of Colistin Resistance in Klebsiella pneumoniae in a Tertiary Care Teaching Hospital

• DOI: 10.3389/fcimb.2021.673503
• Publication Date: 2021-10-26T05:49:10Z
• Authors: Yanling Liu; Yiqing Lin; Ziwen Wang; Niya Hu; Qiong Liu; Wenkai Zhou; Xiuzhen Li; Longhua Hu; Jian Guo; Xiaotian Huang; Lingbing Zeng
• Keywords: Colistin; MCR-1

Background Over the last two decades, prevalence of colistin resistance among members Enterobacteriaceae has been increasing, particularly Klebsiella pneumoniae isolates; this limits potential use and leads to worsened clinical outcomes. Methods We investigated genetic characteristics colistin-resistant K. (COLR-KP) in isolates using genomic sequencing. Results In total, 53 K . (4.5%, 53/1,171) were confirmed as COLR-KP, which eight carried mobile ( mcr ) gene. Although overall rate (0.7%, 8/1,171) -like genes remained relatively low, presence (15.1%, 8/53) COLR-KP indicated that gene was already widespread hospital setting. randomly selected 13 (four -bearing nine non- isolates) for whole-genome sequencing, including pandrug-resistant four sequence type 11 (ST11) isolates. Phylogenetic analysis revealed all genetically diverse. Among isolates, three (KP4, KP18, KP30) positive mcr-1 one (KP23) mcr-8 ; none other detected. The KP4 KP30 located an IncX4 plasmid (approximately 33 kb) could be successfully transferred Escherichia coli J53AZ R contrast, KP23 IncFII ), not by conjugation. mcr-1-producing isolate KP18 coexists a novel plasmid-carried tigecycline tmexCD1-toprJ1. most common chromosomal mutation associated with T246A amino acid substitution PmrB, identified (11/13, 84.6%). All ST11 additionally had R256G substitution. Critical virulence factors hypervirulent detected these included aerobactin, salmochelin, yersiniabactin. Conclusion found emerged our growing at increasing rate. Simultaneous emergence hypervirulence colistin–tigecycline–carbapenem epidemic clone also observed; highlights significance active continuous surveillance.