Publication details
Comparative study of plasmids carrying mcr-1 gene in Gram-negative bacteria from raw meat products
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| Year of publication | 2019 |
| Type | Article in Proceedings |
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| Description | Currently, there are described several types of horizontally transmitted plasmids carrying multiple variants of mcr genes encoding colistin resistance, the most prevalent is mcr 1. This study was focused on plasmid characteristics of Enterobacteriaceae carrying mcr 1 gene obtained from retailed raw meat products. In total 16 isolates carrying mcr-1 were obtained from 11 meat samples. They belonged to various species - Escherichia coli (12), Klebsiella pneumoniae (2) and Citrobacter braakii (1). The sequencing was performed using Illumina MiSeq and Oxford Nanopore MinION platforms and the sequences of plasmids carrying mcr-1 gene were obtained by hybrid assembly. The content of plasmid sequences was analysed and the comparison of plasmid sequences was performed. The outcome showed three plasmid types (IncX4, IncHI2 and IncI2) carrying mcr-1 gene. The most prevalent plasmid type was IncX4 detected in E. coli (8) and K. pneumoniae (2) with size between ~33 to ~34 kb with two exceptions. IncHI2 plasmid was isolated from E. coli (4), it varied in size (~153 kb to 284 kb) and carried also other resistance genes. E. coli (1) and C. braakii (1) isolates from one meat sample carried mcr-1 on IncI2 plasmid (~60 kb). The results of this study indicate a possible spread of plasmid mediated colistin resistance genes via bacteria contained in raw meat. While most of the tested IncX4 and IncI2 plasmids were found to be conserved and carried only mcr-1, the tested IncHI2 plasmids carrying mcr-1 were diverse in size and in the content of genes encoding resistance to other antibiotics. |