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Objectives: To characterize the genetic environment of the carbapenem resistance determinant in Proteus vulgaris of swine origin.Methods: The carbapenem-resistant P. vulgaris strain BC22 was isolated from a faecal swab from a diseased pig with diarrhoea in Sichuan Province of China in 2018. The presence of carbapenemase genes was screened by PCR. WGS and bioinformatics analysis were performed to analyse the genetic environment of the carbapenem resistance determinant.Results: P. vulgaris strain BC22 was found to harbour the carbapenemase gene blaNDM-1. WGS data revealed that blaNDM-1 was located in a truncated ISAba125 composite transposon. The carbapenem resistance gene blaNDM-1 and 20 other resistance genes, including the multiresistance gene cfr and the bifunctional aminoglycoside/quinolone resistance gene aac(6')-lb-cr, were located in a novel SXT/R391 integrative and conjugative element (ICE). This new SXT/R391 ICE of 148.7 kb was chromosomally located, and could be transferred to Escherichia coli.Conclusions: Here, we report a carbapenemase gene, blaNDM-1, integrated into an SXT/R391 ICE. Our study highlights that this SXT/R391 ICE may facilitate the dissemination of clinically important resistance genes such as blaNDM-1, cfr and aac(6')-lb-cr. [ABSTRACT FROM AUTHOR]

IncC plasmids are of great concern as vehicles of broad-spectrum cephalosporins and carbapenems resistance genes bla CMY and bla NDM . The aim of this study was to sequence and characterize a multidrug resistance (MDR) IncC plasmid (pPm14C18) recovered from Proteus mirabilis . pPm14C18 was identified in a CMY-2-producing P. mirabilis isolate from chicken in China in 2014, and could be transferred to Escherichia coli conferring an MDR phenotype. Whole genome sequencing confirmed pPm14C18 was a novel type 1/2 hybrid IncC plasmid 165,992 bp in size, containing fifteen antimicrobial resistance genes. It harboured a novel MDR mosaic region comprised of a hybrid Tn 21 tnp -pDU mer , in which bla CTX-M-65 , dfrA32 and ereA were firstly reported in IncC plasmid. Phylogenetic relationship reconstruction based on the nucleotide sequences of the 52 IncC backbones showed all type 1 IncC plasmids were clustered into one clade, and then merged with pPm14C18 and finally with the type 2 IncC plasmids and another type 1/2 hybrid IncC plasmid pYR1. The MDR IncC plasmids in P. mirabilis of animal origin might threaten public health, which should be drawn more attention. [ABSTRACT FROM AUTHOR]