Emergence of IncX3 Plasmid-Harboring bla NDM- 5 Dominated by Escherichia coli ST48 in a Goose Farm in Jiangsu, China

Abstract

Twelve carbapenem-resistant Escherichia coli strains were obtained from goose farms in Jiangsu, China. These isolates were resistant to multiple antimicrobials, and positive for the bla _{NDM- 5}. The carbapenem-resistance of all strains mediated by bla _{NDM- 5} were successfully conjugated to E. coli J53. S1-PFGE and WGS results showed bla _{NDM- 5} was located on IncX3 conjugative plasmids with a size of ca. 46 kb. All bla _{NDM- 5}-bearing IncX3 plasmids shared the same genetic context almost identical to pNDM_MGR194-bla _{NDM- 5} and pNDM-QD28-bla _{NDM- 5} reported in India and China, respectively. The twelve strains belonged to three STs, in which the dominant type of E. coli isolated from breeding goose farm carrying bla _{NDM- 5} was ST48. The emergence of bla _{NDM- 5}-bearing strains in goose farms and the clonal transmission of E. coli within the breeding goose farm highlighted the potential reservoir of carbapenemase genes in waterfowl farming system, which may further contaminate environments and pose a threat to public health. Comprehensive surveillance of carbapenem-resistant bacteria in goose farms warrants further study to evaluate the underlying risks.

Keywords: E. coli; blaNDM–5; carbapenemase genes; long-read sequencing; plasmids.

FIGURE 1

Sequence alignment analysis of IncX3 bla_NDM–5 plasmids. (A) Linear alignment of four bla_NDM–5-bearing E. coli strains. pNDM-QD28 (GenBank accession no. KU167608.1) and pNDM_MGR194-bla_NDM–5 (GenBank accession KF220657.1) were the reported bla_NDM–5-bearing plasmids. Plasmids pL41-1-4, pL53-4, pL65-9 and pL103-2-5 shown identical structure with pL100-4. (B) Circular comparison between the bla_NDM–5-bearing IncX3 plasmid pL37-3 and the assembled contigs of other six bla_NDM–5 positive strains without MinION data and based on Illumina data.