title: Molecular basis of bacterial resistance to chloramphenicol and florfenicol.
abstract: Chloramphenicol (Cm) and its fluorinated derivative florfenicol (Ff) represent highly potent inhibitors of bacterial protein biosynthesis. As a consequence of the use of Cm in human and veterinary medicine, bacterial pathogens of various species and genera have developed and/or acquired Cm resistance. Ff is solely used in veterinary medicine and has been introduced into clinical use in the mid-1990s. Of the Cm resistance genes known to date, only a small number also mediates resistance to Ff. In this review, we present an overview of the different mechanisms responsible for resistance to Cm and Ff with particular focus on the two different types of chloramphenicol acetyltransferases (CATs), specific exporters and multidrug transporters. Phylogenetic trees of the different CAT proteins and exporter proteins were constructed on the basis of a multisequence alignment. Moreover, information is provided on the mobile genetic elements carrying Cm or Cm/Ff resistance genes to provide a basis for the understanding of the distribution and the spread of Cm resistance--even in the absence of a selective pressure imposed by the use of Cm or Ff.
authors.affiliation: Institut für Tierzucht, Bundesforschungsanstalt für Landwirtschaft (FAL), Höltystrasse 10, 31535 Neustadt-Mariensee, Germany. stefan.schwarz@fal.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwarz
authors.forename: Corinna
authors.initials: C
authors.lastname: Kehrenberg
authors.forename: Benoît
authors.initials: B
authors.lastname: Doublet
authors.forename: Axel
authors.initials: A
authors.lastname: Cloeckaert
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002701:Chloramphenicol / Q000494:pharmacology*; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D002702:Chloramphenicol Resistance / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000235:genetics; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D013839:Thiamphenicol / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002701:Chloramphenicol; C035534:florfenicol; D015500:Chloramphenicol O-Acetyltransferase; D013839:Thiamphenicol