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Fitness Advantage of mcr-1–Bearing IncI2 and IncX4 Plasmids in Vitro
- Source :
- Frontiers in Microbiology, Vol 9 (2018), Frontiers in Microbiology
- Publication Year :
- 2018
- Publisher :
- Frontiers Media SA, 2018.
-
Abstract
- The objective of this study was to assess the impact of diverse plasmids bearing colistin resistance gene mcr-1 on host fitness. Forty-seven commensal E. coli isolates recovered from the pig farm where mcr-1 was first identified were screened for mcr-1. mcr-1-bearing plasmids were characterized by sequencing. The fitness impact of mcr-1-bearing plasmids was evaluated by in vitro competition assays. Twenty-seven (57.5%) E. coli isolates were positive for mcr-1. The mcr-1 genes were mainly located on plasmids belonging to IncI2 (n = 5), IncX4 (n = 11), IncHI2/ST3 (n = 8), IncFII (n = 2), and IncY (n = 2). InHI2 plasmids also carried other resistance genes (floR, blaCTX-M, and fosA3) and were only detected in isolates from nursery pigs. Sequences of the representative mcr-1-bearing plasmids were almost identical to those of the corresponding plasmid types reported previously. An increase in the fitness of IncI2- and IncX4-carrying strains was observed, while the presence of IncHI2, IncFII and IncY plasmids showed a fitness cost although an insignificant fitness increase was initially observed in IncFII or IncY plasmids-containing strains. Acquisition of IncI2-type plasmid was more beneficial for host E. coli DH5α than either IncHI2 or IncX4 plasmid, while transformants with IncHI2-type plasmid presented a competitive disadvantage against IncI2 or IncX4 plasmid containing strains. In conclusion, IncI2, IncX4, and IncHI2 were the major plasmid types driving the dissemination of mcr-1 in this farm. Increased fitness or co-selection by other antimicrobials might contribute to the further dissemination of the three epidemic mcr-1-positive plasmids (IncI2, IncX4, and IncHI2) in this farm and worldwide.
- Subjects :
- 0301 basic medicine
Microbiology (medical)
media_common.quotation_subject
030106 microbiology
lcsh:QR1-502
Biology
mcr-1
medicine.disease_cause
Microbiology
Competition (biology)
lcsh:Microbiology
03 medical and health sciences
Plasmid
plasmid
medicine
Escherichia coli
colistin
Gene
media_common
Original Research
Genetics
Host (biology)
In vitro
fitness
Colistin
MCR-1
hormones, hormone substitutes, and hormone antagonists
medicine.drug
Subjects
Details
- Language :
- English
- ISSN :
- 1664302X
- Volume :
- 9
- Database :
- OpenAIRE
- Journal :
- Frontiers in Microbiology
- Accession number :
- edsair.doi.dedup.....61b6c62b6dd6cd842b391a37d25fe576
- Full Text :
- https://doi.org/10.3389/fmicb.2018.00331