title: A new tetracycline-resistance determinant, class E, isolated from Enterobacteriaceae.
abstract: A fifth tetracycline(Tc)-resistance determinant, designated class E, has been identified on a transferable plasmid found in a fecal strain of Escherichia coli. This determinant does not show homology by DNA-DNA hybridization at high stringency with any of four other Tc resistance determinants (classes A, B, C and D) previously described among the Enterobacteriaceae. Resistance is inducible by 1 microgram Tc/ml and increases the minimum inhibitory concentration 130-fold for Tc and 3.5-fold for minocycline. The mechanism, like that of the other four determinants examined, appears to involve an active efflux of the drug. Using a 32P-labeled cloned fragment containing the resistance determinant, we have found the determinant in Aeromonas, but not in any of over 200 other E. coli strains tested.
mesh_terms: D000333:Aeromonas / Q000187:drug effects / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D008911:Minocycline / Q000494:pharmacology; D011815:R Factors; D013752:Tetracycline / Q000494:pharmacology
chemical_list: D004262:DNA Restriction Enzymes; D013752:Tetracycline; D008911:Minocycline