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[Retracted] R plasmid in Escherichia coli O103 coding for colonization of the rabbit intestinal tract.
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Edité par CCSD ; American Society for Microbiology -
Volume 59, no. 6, p. 1888-1892: It was reported that an R plasmid harbored by the Escherichia coli 0103 strain GV wasresponsible for the ability of the strain to colonize the intestinal tract of young rabbits. This result could not be confirmed inlater experiments that we performed with various transconjugants that had acquired the R plasmid of strain GV. Under verystrictly controlled experimental conditions, none of the transconjugants colonized the rabbit intestinal tract.As a result, Fig. 2, 3, and 4 in our article and the corresponding results contained therein can no longer be considered validand our conclusion that the R plasmid codes for colonization of the rabbit intestinal tract can no longer be substantiated. Weare therefore retracting these parts of the article. Further experiments are being carried out to assess the exact role of the Rplasmid.See: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC281197/?page=1. One rabbit pathogenic Escherichia coli strain, belonging to serogroup O103, harbors a self-transferable 117-kb plasmid (pREC-1) encoding resistance to several antibiotics. The role of this R plasmid in the colonization of the digestive tract in specific-pathogen-free (E. coli O103-free) rabbits was studied. Five-week-old rabbits were inoculated with the wild-type strain, with its variant cured of the plasmid, with an E. coli K-12 strain, or with an untypeable E. coli strain from a healthy rabbit. No symptoms and no mortality were observed in animals inoculated with strains without the plasmid pREC-1, but 87.5% of the rabbits infected by the wild strain died, generally with bloody diarrhea, between days 5 and 15 postinfection. The weight gain of animals was strongly reduced. Transfer of the plasmid to the cured strain or to nonvirulent strains led these strains to induce the same pathology but with a lower mortality. Colonization of the gut by the O103 strain and symptoms of bloody diarrhea are thus related to the presence of the pREC-1 plasmid. The GV strain, which does not produce classical heat-labile enterotoxin or heat-stable enterotoxin and is not invasive, could be considered an enteropathogenic E. coli-like strain. The presence of a conjugative plasmid such as pREC-1 encoding both antibiotic resistance and virulence determinants in O103 E. coli from rabbits could represent a prominent epidemiological hazard under selective pressure by antibiotic therapy.
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