title: Molecular analysis of chromosomally florfenicol-resistant Escherichia coli isolates from France and Germany.
abstract: The aim of this study was to analyse chromosomally florfenicol-resistant Escherichia coli isolates for their genetic relatedness, and also for the presence of the floR gene and its adjacent regions, in order to compare these regions with those associated with a floR gene located on a conjugative plasmid from E. coli. Twenty-two bovine E. coli from France and Germany were examined. Florfenicol resistance was determined by MIC determination. The presence of the floR gene was confirmed by hybridization and PCR analysis. The E. coli isolates were investigated by macrorestriction analysis. The 22 florfenicol-resistant E. coli (MICs 64->128 mg/L) differed in their BlnI macrorestriction patterns. Single or double copies of the floR gene were detected by hybridization on different-sized chromosomal EcoRI, BamHI and BglI fragments. The floR-flanking regions also proved to be variable as confirmed by hybridization experiments. The detection of chromosomal floR gene copies in unrelated E. coli isolates supplements the observations of floR genes on plasmids in E. coli and confirms their potential to integrate into the chromosome. The RFLPs of floR gene-carrying restriction fragments might suggest variable chromosomal integration sites.
authors.affiliation: Station de Pathologie Aviaire et Parasitologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Doublet
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwarz
authors.forename: Erika
authors.initials: E
authors.lastname: Nussbeck
authors.forename: Sylvie
authors.initials: S
authors.lastname: Baucheron
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Martel
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Chaslus-Dancla
authors.forename: Axel
authors.initials: A
authors.lastname: Cloeckaert
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D002876:Chromosomes, Bacterial / Q000187:drug effects / Q000235:genetics*; D015342:DNA Probes / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D005602:France / Q000453:epidemiology; D005858:Germany / Q000453:epidemiology; D008826:Microbial Sensitivity Tests / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods; D013839:Thiamphenicol / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015342:DNA Probes; C035534:florfenicol; D013839:Thiamphenicol