Dissemination of IncI plasmid encoding bla CTX-M-1 is not hampered by its fitness cost in the pig's gut.
Antimicrob Agents Chemother
; 67(10): e0011123, 2023 10 18.
Article
in En
| MEDLINE
| ID: mdl-37702541
ABSTRACT
Multiresistance plasmids belonging to the IncI incompatibility group have become one of the most pervasive plasmid types in extended-spectrum beta-lactamase-producing Escherichia coli of animal origin. The extent of the burden imposed on the bacterial cell by these plasmids seems to modulate the emergence of "epidemic" plasmids. However, in vivo data in the natural environment of the strains are scarce. Here, we investigated the cost of a bla CTX-M-1-IncI1 epidemic plasmid in a commensal E. coli animal strain, UB12-RC, before and after oral inoculation of 15 6- to 8-week- old specific-pathogen-free pigs. Growth rate in rich medium was determined on (i) UB12-RC and derivatives, with or without plasmid, in vivo and/or in vitro evolved, and (ii) strains that acquired the plasmid in the gut during the experiment. Although bla CTX-M-1-IncI1 plasmid imposed no measurable burden on the recipient strain after conjugation and during the longitudinal carriage in the pig's gut, we observed a significant difference in the bacterial growth rate between IncI1 plasmid-carrying and plasmid-free isolates collected during in vivo carriage. Only a few mutations on the chromosome of the UB12-RC derivatives were detected by whole-genome sequencing. RNA-Seq analysis of a selected set of these strains showed that transcriptional responses to the bla CTX-M-1-IncI1 acquisition were limited, affecting metabolism, stress response, and motility functions. Our data suggest that the effect of IncI plasmid on host cells is limited, fitness cost being insufficient to act as a barrier to IncI plasmid spread among natural population of E. coli in the gut niche.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Escherichia coli
/
Escherichia coli Infections
Type of study:
Health_economic_evaluation
Limits:
Animals
Language:
En
Journal:
Antimicrob Agents Chemother
Year:
2023
Document type:
Article
Affiliation country: