JAC Advance Access published online on July 22, 2005
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dki255
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Bristol Centre for Antimicrobial Research, Department of Pathology and Microbiology, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
* To whom correspondence should be addressed. Objectives: Little is known of the fitness cost that antibiotic resistance exerts on wild-type bacteria, especially in their natural environments. We therefore examined the fitness costs that several antibiotic resistance elements imposed on a wild-type Escherichia coli isolate, both in the laboratory and in a pig gut colonization model. Methods: Plasmid R46, Tn1 and Tn7 and a K42R RpsL substitution were separately introduced into E. coli 345-2 RifC, a rifampicin-resistant derivative of a recent porcine isolate. The insertion site of Tn1 was determined by DNA sequencing. The fitness cost of each resistance element was assessed in vitro by pairwise growth competition and in vivo by regularly monitoring the recovery of strains from faeces for 21 days following oral inoculation of organic piglets. Each derivative of 345-2 RifC carrying a resistance element was grown in antibiotic-free broth for 200 generations and the experiments to assess fitness were repeated. Results: RpsL K42R was found to impose a small fitness cost on E. coli 345-2 RifC in vitro but did not compromise survival in vivo. R46 imposed a cost both before and after laboratory passage in vitro, but only the pre-passage strain was at a disadvantage in vivo. The post-passage isolate had an advantage in pigs. Acquisition of Tn7 had no impact on the fitness of E. coli 345-2 RifC. Two derivatives containing Tn1 were isolated and, in both cases, the transposon inserted into the same cryptic chromosomal sequence. Acquisition of Tn1 improved fitness of E. coli 345-2 RifC in vitro and in vivo in the case of the first derivative, but in the case of a second, independent derivative, Tn1 had a neutral effect on fitness. Conclusions: The fitness impact imposed on E. coli 345-2 RifC by carriage of antibiotic resistance elements was generally low or non-existent, suggesting that once established, resistance may be difficult to eliminate through reduction in prescribing alone.
Received March 4, 2005
Revised June 3, 2005
Accepted June 23, 2005
Original article
Assessment of the fitness impacts on Escherichia coli of acquisition of antibiotic resistance genes encoded by different types of genetic element
2 Division of Animal Health and Husbandry, Department of Clinical Veterinary Science, University of Bristol, Langford BS40 5DU, UK
V. I. Enne, E-mail: v.i.enne{at}bristol.ac.uk
Abstract 
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Sundqvist, P. Geli, D. I. Andersson, M. Sjolund-Karlsson, A. Runehagen, H. Cars, K. Abelson-Storby, O. Cars, and G. Kahlmeter Little evidence for reversibility of trimethoprim resistance after a drastic reduction in trimethoprim use J. Antimicrob. Chemother., November 8, 2009; (2009) dkp387v1. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. M. Hawkey and A. M. Jones The changing epidemiology of resistance J. Antimicrob. Chemother., September 1, 2009; 64(suppl_1): i3 - i10. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Bibbal, V. Dupouy, M. F. Prere, P. L. Toutain, and A. Bousquet-Melou Relatedness of Escherichia coli Strains with Different Susceptibility Phenotypes Isolated from Swine Feces during Ampicillin Treatment Appl. Envir. Microbiol., May 15, 2009; 75(10): 2999 - 3006. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. C. Chee-Sanford, R. I. Mackie, S. Koike, I. G. Krapac, Y.-F. Lin, A. C. Yannarell, S. Maxwell, and R. I. Aminov Fate and Transport of Antibiotic Residues and Antibiotic Resistance Genes following Land Application of Manure Waste J. Environ. Qual., April 27, 2009; 38(3): 1086 - 1108. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Pallecchi, C. Lucchetti, A. Bartoloni, F. Bartalesi, A. Mantella, H. Gamboa, A. Carattoli, F. Paradisi, and G. M. Rossolini Population Structure and Resistance Genes in Antibiotic-Resistant Bacteria from a Remote Community with Minimal Antibiotic Exposure Antimicrob. Agents Chemother., April 1, 2007; 51(4): 1179 - 1184. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. H. Dahl, D. D. G. Mater, M. J. Flores, P. J. Johnsen, T. Midtvedt, G. Corthier, and A. Sundsfjord Transfer of plasmid and chromosomal glycopeptide resistance determinants occurs more readily in the digestive tract of mice than in vitro and exconjugants can persist stably in vivo in the absence of glycopeptide selection J. Antimicrob. Chemother., March 1, 2007; 59(3): 478 - 486. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. I. Enne, A. A. Delsol, J. M. Roe, and P. M. Bennett Evidence of Antibiotic Resistance Gene Silencing in Escherichia coli. Antimicrob. Agents Chemother., September 1, 2006; 50(9): 3003 - 3010. [Abstract] [Full Text] [PDF]
|
|